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Tectonic, magmatic, and metallogenic evolution of the Tethyan orogen: From subduction to collision
Abstract
This paper reviews the tectonic, magmatic, and metallogenic history of the Tethyan orogen from the Carpathians to Indochina. Focus is placed on the formation of porphyry Cu ± Mo ± Au deposits, as being the most characteristic mineral deposit type formed during both subduction and collisional processes in this region. Relatively little is known about the history of the Paleotethys ocean, which opened and closed between Gondwana and Eurasia in the Paleozoic, and few ore deposits are preserved from this period. The Neotethyan ocean opened in the Permian–Early Triassic as the Cimmerian continental fragments (the cores of Turkey, Iran, Tibet, and Indochina) rifted from the northern Gondwana margin and drifted northwards. These microcontinents docked with the Eurasian margin at various points in the Mesozoic and Cenozoic, and formed a complex archipelago involving several small back-arc basins and remnants of the Paleotethyan ocean. The main Neotethyan ocean and these smaller basins were largely eliminated by collision with India and Africa–Arabia in the early Eocene and early-mid Miocene, respectively, although Neotethyan subduction continues beneath the Hellenic arc and the Makran.
... The Tethys metallogenic domain ranges across the European Alps, Carpathians, Caucasus, Iran Plateau, Tibetan Plateau, and Southeast Asia (e.g., Zhu et al., 2022), extending over 120,00 km west to east. It is one of the major metallogenic provinces globally (Richards, 2015). In terms of ages, the Tethyan belt can be divided into Proto-Tethys, Palaeo-Tethys, and Neo-Tethys stages, representing the oceans during the Early Palaeozoic, Late Palaeozoic, and Mesozoic to Cenozoic eras, respectively (e.g., Zhu et al., 2022;Cao et al., 2023a). ...
... In terms of ages, the Tethyan belt can be divided into Proto-Tethys, Palaeo-Tethys, and Neo-Tethys stages, representing the oceans during the Early Palaeozoic, Late Palaeozoic, and Mesozoic to Cenozoic eras, respectively (e.g., Zhu et al., 2022;Cao et al., 2023a). Evolution of the Neo-Tethys Ocean persisted from the Mesozoic to Paleogene-Neogene (Richards, 2015;Zhu et al., 2022). On the Tibetan Plateau, evolution traces of the Neo-Tethys Ocean have been completely preserved, including the Bangong-Nujiang Tethys suture zone (closed at $ 140 Ma) on the northern side of the Lhasa Terrane and the Indus-Yarlung Zangbo Tethys suture zone (closed at $ 65 Ma) on the southern side of the Lhasa Terrane 2023) (Fig. 18). ...
... In southeastern Europe, subduction of Neo-Tethyan oceanic slab produced a set of Late Cretaceous calc-alkaline arc magmas across the Apuseni-Banat-Timok-Panagyurishte belt of Romania, Serbia and Bulgaria (e.g., Ciobanu et al., 2002). The belt hosts a series of porphyry Cu-Au, skarn Cu-Fe, and epithermal Cu-Au deposits that formed between 92-84 Ma, including the Elatsite porphyry Cu-Au (92 Ma (Ciobanu et al., 2002;Yigit, 2009;Richards, 2015;Knaak et al., 2016, and references therein). From the Caucasus to Iran Plateau, Late Cretaceous mineralization is scarce. ...
... The Tethyan metallogenic domain is rich in mineral resources with various deposit types, including porphyry-skarn Cu-Mo-Au deposits and epithermal Cu-Au deposits around the world (Wang et al., 2020a,b;Richards, 2015b). The spatial distribution of the deposits is extremely fragmented, with the majority concentrated in the Neo-Tethyan orogenic belt (Bao et al., 2023), whereas deposits in the Paleo-Tethyan orogenic belt are rare (Fig. 1a;Richards, 2015b;Richards and Ş engör, 2017). ...
... The Tethyan metallogenic domain is rich in mineral resources with various deposit types, including porphyry-skarn Cu-Mo-Au deposits and epithermal Cu-Au deposits around the world (Wang et al., 2020a,b;Richards, 2015b). The spatial distribution of the deposits is extremely fragmented, with the majority concentrated in the Neo-Tethyan orogenic belt (Bao et al., 2023), whereas deposits in the Paleo-Tethyan orogenic belt are rare (Fig. 1a;Richards, 2015b;Richards and Ş engör, 2017). For example, the Sanjiang region (Jinshajiang, Lancangjiang and Nujiang) in southwestern China, which is located in the eastern Paleo-Tethyan orogenic belt, lacks porphyry Cu deposits directly associated with the Paleo-Tethyan oceanic subduction. ...
... In reduced magmatic-hydrothermal systems, S solubility is limited and exists as S 2- (Jugo et al., 2010;Alex and Zajacz, 2022;Boulliung and Wood, 2023), leading to extensive saturation and segregation of early magmatic sulfide phases and thus a relative chalcophile deficit in the residual magma, which is not conducive to the formation of Cu-rich hydrothermal fluids (Sillitoe, 2010;Sun et al., 2015;Richards, 2015b;Hou et al., 2015;Kim et al., 2023). This process is thought to have inhibited the formation of porphyry Cu deposits in the Paleo-Tethyan orogenic belt (Richards and Ş engör, 2017;Zhu et al., 2022). ...
... The Daralu Porphyry Copper Deposits (PCDs) are defined as high-tonnage, low-to medium-grade deposits (Sinclair, 2007), and they are globally the most important reserves of copper (Richards, 2015;Sillitoe, 2010). These deposits were formed by the evolution of high temperature (300−700ºC) magmatic-hydrothermal fluids (Li et al., 2012;Richards, 2011). ...
... An adakite-related genesis has been suggested for PCDs in post-collisional margins (e.g. southern Tibet: Hou et al., 2015;Mao et al., 2014;Yang et al., 2008, and western Asia: Hezarkhani and Williams-Jones, 1998;Richards, 2015;Shafiei et al., 2009). The adakitic magmas which have high potential for forming the major PCDs (Hollings et al., 2005), show high ratios of La/Yb and Sr/Y, coupled with low Yb and Y, with no Eu anomalies (Eu/ Eu * ≥1). ...
... The Urmieh-Dokhtar Magmatic Arc (UDMA, Fig. 1A) is a well-known Cu-bearing region, where a wide range of world class porphyry copper systems have been reported and studied (e.g. Asadi, 2018;Atapour and Aftabi, 2021;Hassanzadeh, 1993;Hezarkhani and Williams-Jones, 1998;Khosravi et al., 2019;Mohammaddoost et al., 2017;Richards et al., 2012;Richards, 2015;Shafiei et al., 2009;Zarasvandi et al., 2019). According to Zarasvandi et al. (2015) this is one of the best examples, in the world, of prolonged continental arcs, where the Neo-Tethys oceanic plate was subducted beneath the central Iran continental plate. ...
The Miocene Daralu Porphyry Copper Deposits (PCDs) is found associated with other porphyries such as Sarcheshmeh and Meiduk in the Kerman Cenozoic Magmatic Arc (KCMA), southern Iran. In this research, we provided whole-rock geochemical data, characteristics of hydrothermal fluid and sulfur isotope composition of the Daralu intrusive body, and discussed the nature, tectonic setting and fluid evolution of this deposit aiming to investigate its fertility. The Daralu porphyry shows adakites affinity, that is, high Sr/Y and La/Yb ratios and positive Eu anomalies. The REEs patterns indicate a strong fractionation ([La/Yb]n= 28.73). High La/Sm and Dy/Yb ratios suggest enrichment of amphibole and garnet as residual phases in melt source, whereas partial melting of plagioclase increases Eu and Sr in the parent magma. The presence of garnet implies a pressure equivalent to the thickness of more than 40km of crust. To elucidate the evolutionary history of fluids and the origin of the Daralu deposit, we focused on the origin and composition of the fluid through petrography, laser Raman, and microthermometry studies of fluid inclusions. The fluid inclusions have been divided into four types: vapor (type I), aqueous-vapor (type II), CO2-bearing (type III), and multiphase (type IV). The Raman shifts included 1284 and 1388 cm−1 for CO2 and 2750–3900 cm−1 for H2O. The events such as NaCl supersaturation, exhausting of CO2-rich components, high oxygen fugacity and temperature decreasing through mineralization stages were critical in controlling the fertility of the Daralu PCD. The obtained δ34S data for sulfides yielded an average of +5.5‰. Based on the observed features, it was concluded that Daralu porphyry shares formation conditions with other productive porphyries of the KMCA.
... The enrichment in LILE and negative trough of Nb, Ta, and Ti (Fig. 13B) indicates a magma sourced from asthenospheric mantle metasomatized by slab-derived fluids may have been involved for generation of the granitoids (Richards, 2003;Sillitoe, 2010;Tatsumi et al., 1986). Based on these geochemical signatures, it can be inferred that the Bayanbulag intrusive complex was sourced from previously subduction-modified lithosphere in a post-collisional setting as the postsubduction magmas share similar geochemical signatures with precursor arc magmas (Richards, 2009(Richards, , 2015. It is noted that similar geochemical signatures were demonstrated in porphyry Cu-Mo deposits formed in a postcollisional setting such as the Qulong, Bairong, and Chongjiang porphyry Cu-Mo deposits in the Gangdese porphyry Cu belt (Li et al., 2011). ...
... Magmas with calc-alkaline affinities dominate in mature continental arcs and post-collisional zones as opposed to tholeiites that dominate in immature island arcs and nascent continental arcs (Hildreth and Moorbath, 1988;Richards, 2015;Richards et al., 2012). The origin of calc-alkaline signatures is still controversial whether the signature: (1) originates from a mantle wedge (Carmichael, 1991); (2) develops through magma fractionation (Audétat, 2010;Soesoo, 2000); or (3) forms through contamination and mixing with Si-rich and Fe-poor crustal materials while ascending (Hoshino et al., 2016). ...
... The broadly accepted hypothesis is that calc-alkaline magmas are sourced from the metasomatized mantle wedge and form through early fractionation of Fe-rich minerals such as magnetite, amphibole, and garnet (Sisson and Grove, 1993;Tang et al., 2018) as a consequence of high water contents in a mature arc setting (Richards, 2003;Richards et al., 2012). Additionally, partial melting of the previously subduction-modified lithosphere and juvenile lower crust share many similarities with respect to geochemical signatures with the arc magmas, and therefore, have calcalkaline to mildly alkaline character (Richards, 2009(Richards, , 2015. The fact that the formation of Zuun Mod is spatiotemporally associated with the calc-alkaline to high-K calc-alkaline granitoids of the Bayanbulag complex implies that the host granitoids are the most extreme representative of these calc-alkalic differentiation trend (Loucks, 2014) and formed in a thickened crust because calc-alkalinity of magma is linearly correlated with crust thickness (Chiaradia, 2014). ...
... Porphyry copper deposits (PCD) have generally been linked to the evolution of magmatic arcs above subduction zones (Richards 2003;Sillitoe 2010), and are directly related to the petrogenesis of arc magmas, mostly derived by partial melting of a metasomatized mantle wedge (Richards 2009(Richards , 2011. However, a suite of PCD has been recently recognized in post-collisional settings along the Tethyan metallogenic belt (Hou et al. 2015a;Richards 2015;Moritz et al. 2016). Previous investigations suggested that magmas responsible for the formation of post-collisional PCD were predominantly formed by partial melting of a lower crust previously fertilized in metals (Richards 2009(Richards , 2015Asadi et al. 2014;Hou et al. 2015a;Zheng et al. 2019). ...
... However, a suite of PCD has been recently recognized in post-collisional settings along the Tethyan metallogenic belt (Hou et al. 2015a;Richards 2015;Moritz et al. 2016). Previous investigations suggested that magmas responsible for the formation of post-collisional PCD were predominantly formed by partial melting of a lower crust previously fertilized in metals (Richards 2009(Richards , 2015Asadi et al. 2014;Hou et al. 2015a;Zheng et al. 2019). Although the origin of subduction-and post-collision-related PCD has been investigated in numerous studies (e.g., Richards 2009Richards , 2011Hou et al. 2015a), the genetic link between both types of PCD is still poorly understood. ...
... B During the Miocene, underplating of hydrated and oxidized mantle-derived melts beneath thickened lower crust triggered melting of Jurassic lower crustal cumulates, which led to the formation of the Miocene giant PCD in a post-collision setting (Wang et al. 2014bHou et al. 2015a;Yang et al. 2015). Because of the Cu-enrichment of sulfides in the Jurassic lower crustal cumulates in the northern back-arc zone, the Miocene PCD were preferentially generated in the northern subbelt formation of PCD are characterized by high fO 2 and high H 2 O concentration (Richards 2003(Richards , 2015Sillitoe 2010;Wang et al. 2014a, b;Lu et al. 2015;Yang et al. 2016a). A high fO 2 in magmas promotes sulfide solubility, and explains the inhibition of sulfide segregation from magmas at depth, which otherwise may sequester Cu before it can be partitioned into the aqueous phase derived from melts and form PCD at shallower levels (Sillitoe 2010;Richards 2015;Sun et al. 2015). ...
The genetic link between subduction- and collision-related porphyry Cu deposits (PCD) is still not well understood. The Gangdese porphyry Cu belt (GPCB) in southern Tibet hosts two parallel E–W-oriented metallogenic subbelts, including a southern Jurassic subduction-related and a northern Miocene post-collision PCD subbelt. In this study, we combine new and published whole-rock major and trace element data, Cu isotopic compositions and zircon trace element data of Jurassic magmatic rocks from the GPCB. Combined Sr/Y and La/Yb crustal thickness proxies confirm the south to north geometry of the Jurassic arc-back-arc system across the GPCB. The southern Jurassic magmatic arc rocks have systematically higher whole-rock V/Yb ratios, δ⁶⁵Cu values and zircon Eu/Eu* ratios compared to those of the northern back-arc region. This suggests that Jurassic southern arc magmas had higher oxygen fugacity and H2O concentration than the contemporaneous northern back-arc magmas, which was controlled by a steep subduction geometry of the Neo-Tethyan oceanic slab. Hydrous and oxidized magmas resulted in Cu enrichment during magma evolution and generation of Jurassic PCD in the southern magmatic arc by inhibiting early sulfide saturation at deep crustal levels. In contrast, the northern back-arc magmas were less oxidized and less hydrous, which triggered early sulfide saturation, resulting in segregation of Cu-bearing sulfides in lower crustal cumulates that provided a favorable metal source for later Miocene PCD in the northern subbelt. Our study indicates that the Jurassic subduction geometry controlled the formation and distribution of Jurassic subduction-related and Miocene post-collision-related PCD in the GPCB.
... While most of these tectonic units were targeted by several studies (e.g. Artemieva & Thybo, 2008;Brückl et al., 2010;Lordkipanidze et al., 1989;Mjelde et al., 2009a;Nance et al., 2010;Richards, 2015). I will briefly discuss the results of the study area in comparison with previously estimated sediment thickness and geophysical studies. ...
... The convergence of the African plate led to the subduction of different branches of the Tethys Ocean at ca. 65 Ma. The collision and later ongoing continues northward convergence of the African-Arabian lithosphere toward Eurasia formed the Tethys deformation zone (Coward & Dietrich, 1989;Stampfli et al., 2001), extending from Pyrenees to the Zagros mountains; including Alps, Caucasus, and orogenic belts north of the Mediterranean Sea and north of Africa (Castellarin & Cantelli, 2000;McKenzie, 1970;Okay, n.d.;Richards, 2015;Ş engör et al., 2019). The convergence affected even further north structures e.g., the Pannonian Basin (Cloetingh et al., 2004). ...
Despite several geological and geophysical studies that have focused on the estimation of the geometry of the sedimentary basins, the seismic documentation of sediment thickness is inadequately constrained due to the sparse spatial resolution of the expensive seismic and borehole measurements. To provide a new complementary insight into the morphology of the crystalline basement, I have re-examined the radially averaged power spectrum of magnetic anomalies for mapping depth to magnetic basement (DMB). DMB is a proxy of the non-magnetized sediment cover thickness over the magnetized crystalline basement. Synthetic models suggest that the accuracy of the method is not significantly influenced by the unknown magnetic fractal parameter and depth to the bottom of the magnetic slab. The windowing and window size effect on the estimated DMB can be substantial. Our synthetic tests suggest that the uncertainty of the calculated DMB increases with depth if the chosen window size is less than eight times the real DMB. I applied this method to the European, Greenland and North Atlantic regions because of the availability of seismically constrained sediment thickness or depth to the seismic basement (DSB), which allows comparison between DMB and DSB. The estimation of DMB was done by assuming a constant fractal parameter of three within a sliding window and with a variable size from 100 × 100 km in 10 km steps to a maximum size of 200 × 200 km until the estimated DMB is less than one eighth times of the window size. Comparison of DMB with DSB indicates a striking long-wavelength correlation along major sedimentary basins, while discrepancies may indicate limitations in the estimation methods for DMB and DSB.
... Carbonate formations of the Paleozoic basement and Mesozoic-Cenozoic cover contain MVT type deposits (about 15%) in Ireland (Navan, Abbeytown, Ballinalack, Tatestown, etc.), Figure 3. Location of polymetallic deposits and geodynamic regions of Europe (based on materials from [Hasterok et al., 2022;Richards, 2015]). 1 -foredeeps, 2 -accretionary complexes, 3 -island arcs, 4 -magmatic arcs, 5 -orogenic belts, 6superimposed basins, 7 -rifts, 8 -passive margin, 9 -shields, 10 -cratons; 11-13 -age of orogenesis: 11 -Alpides (Ap, MZ-KZ basins), 12 -Hercynides (Hz, Hz+Ap), 13 -Caledonides (Kd); 14 -contours of the Tethys belt. ...
... Polymetallic deposits of Europe and the ratio (from 4:1 to 1:11) of the lower and middle layers of the earth's crust (based on materials from[Laske et al., 2013;Richards, 2015; USGS, 2012]). 1 -troughs of the sedimentary crust, 2 -oil and gas provinces. ...
For the first time, the results of modern studies of the earth's crust based on gravity data from the GOCE satellite Project are used for a comparative regional metallogenic analysis of the geodynamic settings of the formation of polymetallic deposits in Western Europe and the Mediterranean segment of the Tethys belt. It is shown that exhalative sulfide deposits (SEDEX) and cuprous sandstones and shales (SSC) are mainly located in the earth's crust with a predominant development of the lower "basalt" layer of the earth's crust. Pyrite copper and lead-zinc deposits in volcanogenic rocks (VMS), as well as some occurrences of the SEDEX type, are found in supra-subduction island-arc and accretionary crustal settings with a predominant development of the middle "granite" layer. Lead-zinc ores of the Mississippi type (MVT) are localized in deep pericratonic sedimentary basins with petroleum-bearing specialization on the shelf and continental slope, regardless of the stratification of the earth's crust. The results obtained can be used for regional forecasting and metallogenic constructions, prospecting and assessment of new deposits.
... They are subdivided into two main groups, namely deep porphyry copper systems, transitional into shallower porphyry-related base-metal vein and replacement deposits (Henley and Adams, 1992;Hemley and Hunt, 1992;Einaudi et al., 2003;Baumgartner et al., 2008;Sillitoe, 2010;Catchpole et al., 2012), and ultimately near the surface termed high, intermediate, and low-sulfidation epithermal deposits (HS, IS, and LS) (Hedenquist et al., 1998;Muntean and Einaudi, 2001;Einaudi et al., 2003;Wang et al., 2019). The Mesozoic to Cenozoic Alpine-Himalayan Orogenic Belt (Tethyan orogenic belt, TOB), stretching from the Alps, through the Balkan Peninsula, Turkey, Iran, Pakistan, Tibet, Indochina and ultimately into the southwest Pacific, has the best-known concentration of epithermal-porphyry systems (Blundell et al., 2005;Schettino and Turco, 2011;Richards, 2015). Located in the middle of this extensive TOB, Iran hosts many porphyry-epithermal ore mineralized systems along (i) the NW-SE trending Urumieh-Dokhtar Magmatic Arc (UDMA) (e.g., Richards, 2015 and references therein), (ii) the E-W trending Alborz Magmatic Arc (AMA) (Shamanian et al., 2004;Mehrabi and Siani, 2012;Tale Fazel et al., 2019), and (iii) the East Iran Magmatic Assemblage (Richards et al., 2012 and references therein). ...
... The Mesozoic to Cenozoic Alpine-Himalayan Orogenic Belt (Tethyan orogenic belt, TOB), stretching from the Alps, through the Balkan Peninsula, Turkey, Iran, Pakistan, Tibet, Indochina and ultimately into the southwest Pacific, has the best-known concentration of epithermal-porphyry systems (Blundell et al., 2005;Schettino and Turco, 2011;Richards, 2015). Located in the middle of this extensive TOB, Iran hosts many porphyry-epithermal ore mineralized systems along (i) the NW-SE trending Urumieh-Dokhtar Magmatic Arc (UDMA) (e.g., Richards, 2015 and references therein), (ii) the E-W trending Alborz Magmatic Arc (AMA) (Shamanian et al., 2004;Mehrabi and Siani, 2012;Tale Fazel et al., 2019), and (iii) the East Iran Magmatic Assemblage (Richards et al., 2012 and references therein). The western Alborz, here known as the Alborz-Azerbaijan Magmatic Belt, is subdivided into the northwestern Ahar-Arasbaran Belt (AAB) and the southeastern Tarom-Hashtjin Metallogenic Province (THMP) (Ghasemi Siani et al., 2015;Fig. ...
... At the boundary of India Plate and Eurasian Plate, they stuck together, resulting in the stratum for each continental tangled together and formed the Nappe tectonic system. This geologic movement exerted stress on the stratum and caused the movement of different layers [3][4][5][6]. And due to the difference in the rock physical properties, such activity caused the relative slide, some layer went over anther, and some went under another, forming interlayer-gliding facture zone. ...
The Gangdise metallogenic belt has been a popular mineral mine since it was discovered due to its various types of mineral elements, such as copper, iron, zinc, molybdenum, silver, gold, and bismuth, attracting millions of researchers. Moreover, the possible copper output that has been indicated here has already reached 3,000,000 tons. The deposit here is a typical skarn type ore rich in garnet. The article mainly introduces how the minerals in Gangdise metallogenic belt is distributed and investigates how the Gangdise metallogenic belt is formed. Some hypotheses in this article refer to previous investigations in the Gangdise metallogenic belt. This paper concludes that the reasons for the formation of the major ore deposit in Gangdise metallogenic can be regarded as the movement of the Eurasian Plate and India Plate, which can also be defined as the main collision phase, though other geologic changes altered the distribution of the ore body later.
... The SMMP ore deposits are spatially and temporally associated with Oligocene and Miocene magmatism (e.g. Palinkaš et al. 2013;Šoštarić et al. 2013;Cvetković et al. 2016a;Hoerler et al. 2022) that occurred during the transition from collision to post-orogenic extension (late Eocene-early Miocene), roughly between 35 and 20 Ma, pre-dating widespread Miocene extension-related magmatism in the Pannonian Basin (Seghedi et al. 2004;Richards 2015). These Cenozoic magmatic rocks intrude or overlie the basement composed of Mesozoic ophiolites and flysch sediments of the Vardar zone, metamorphic crystalline of the European derived units and limestones of the Adria derived units (Janković, 1990;Heinrich and Neubauer 2002). ...
This study presents and discusses first detailed petrographic, microthermometric and Raman spectroscopic data from quartz-hosted fluid inclusions at Rudnik Zn-Pb-Cu-Ag skarn deposit (Serbia) and combines them with the information on skarn- and ore paragenesis. Three periods in the metamorphic-hydrothermal history of the deposit are recognized: 1) the pre-ore prograde skarn period when garnet-clinopyroxene skarns formed, 2) the syn-ore period that encompasses a retrograde stage marked by epidote and zoisite and a quartz-sulfide stage characterized by quartz, pyrrhotite, sphalerite, galena and chalcopyrite, and 3) the post-ore period associated with precipitation of calcite and quartz. The hydrothermal evolution is inferred from studying six groups of quartz-hosted fluid inclusions (FI). Two-phase FI of high- (Group A) and moderate salinity (Group B) are found in quartz cores and homogenized at 380–390 °C (mode) and 370–380 °C (mode), respectively. Group A FI consists of H2O-NaCl liquids and CO2-CH4 gas mixtures and likely represents the original fluid composition, whereas Group B FI records dilution of the original fluid at constant temperature, with a slight increase in CH4 contents. The quartz cores also contain Group C as volatile-rich FI (mostly CO2 with up to 10 mol% CH4 and H2S) of a moderately low salinity and liquid-rich Group D FI composed of pure water with homogenization temperatures of 180–200 °C (mode). The transitional zones of quartz crystals show overgrowth textures and host Group E FI with low salinity that homogenized at 235–401 °C, which vapour phase is a CO2-CH4 mixture with up to 17 mol% CH4. Group F comprises FI found within the rim zones of quartz crystals and they exhibit a low salinity and homogenization temperatures between 259–365 °C. Accordingly, the hydrothermal history at Rudnik involved: a) mixing of different salinity fluids at high temperatures (Groups A and B—retrograde stage), b) introduction of fluids with high volatile contents (Group C) and cooling of fluids with constant salinity (between Groups E and F), which likely correspond to the quartz-sulfide stage, and c) inflow of meteoric water (Group D—the post-ore quartz-calcite stage).
... Some of these deposits include Qulong porphyry Cu-Mo deposit (Yang et al., 2009;Yang et al., 2015), Lakange porphyry Cu deposit (Leng et al., 2015), Chongjiang porphyry Cu-Mo deposit (Yang et al., 2016), Zhunuo porphyry Cu deposit (Sun et al., 2020) and Jiru porphyry Cu deposit (Zheng et al., 2014). Also, the UDMA of Iran is part of the 12,000 km long Alpine-Himalayan orogenic belt, which is one of the main metallogenic belts of Iran and can be known as host to the most important epithermal Cu-Au-(Ag) and porphyry deposits in Iran (Ayati et al., 2013;Richards, 2015;Zarasvandi et al., 2018). It has a NW-SE trend and ends in the Sanandaj-Sirjan zone in the southwest and Central Iran in the northeast (Mohajjel et al., 2003;Azizi and Stern, 2019;Mokhtari et al., 2022) (Fig. 1). ...
The Hajibolagh-Zalibolagh deposit located northeast of the city of Saveh in the central part of the Urumieh-Dokhtar magmatic arc of Iran, demonstrates vein and breccia vein style copper-(silver) mineralization hosted by Eocene volcano-sedimentary rocks. The main mineralization stage can be divided into four phases, respectively (1) jasperoid+quartz veins, chalcopyrite, and pyrite; (2) quartz veins along with chalcopyrite, bornite, chalcocite, arsenopyrite, and pyrite; (3) quartz-barite veins along with chalcopyrite, bornite, chalcocite and pyrite; and (4) veins of quartz, calcite, hematite, and oligist along with a small number of copper sulfides. The main stages of mineralization are cut by barren post-ore quartz and calcite veinlets. As a result of supergene processes, minerals are oxidized, and malachite, azurite, chrysocolla, chalcocite, covellite, goethite, and hematite are formed, presenting an important exploration guide. The hydrothermal alteration from the center of the vein-veinlets to the outside includes, respectively, silicification, sericitization, intermediate argillic, and propylitic. The average salinity and homogenization temperature (Th) of fluid inclusions is 14.2 wt.% NaCl equiv. and 288 °C, respectively. The coexistence of the vapor phase, liquid-rich phase, and halite-bearing fluid inclusions is a sign of boiling in this hydrothermal system, which has contributed to copper saturation. Sulfur isotope values for pyrite, chalcopyrite, chalcocite, and bornite are mainly from –0.16 to 2.98‰, indicating a probable magmatic source for sulfur. Boiling, dilution, and mixing are the mechanisms for the ore deposition and facilitated the mineralization. The Hajibolagh-Zalibolagh deposit shows the highest similarity to intermediate-sulfidation epithermal deposits. The best environment for the mineralization and fluid circulation in these epithermal deposits is the intersection of faults with the Eocene volcanic and volcano-sedimentary rocks.
... The Tethyan orogen is an important metallogenic belt that hosts various types of ore deposits with quantities of metal resources (Richards, 2015;Moritz and Baker, 2019). The eastern part of the Tethyan metallogenic belt, represented by the Tibetan Plateau, has been reported with large amounts of porphyry Cu-Mo-Au, graniterelated Sn-W, podiform chromite, sediment-hosted Pb-Zn deposits, volcanogenic massive sulfide Cu-Pb-Zn deposits, epithermal and orogenic Au, as well as skarn Fe, and base metal deposits (Hou and Zhang, 2015), mostly distributed in the Xinansanjiang (Hou et al., 2003;Hou et al., 2007;Liang et al., 2009), Gangdese (Yang et al., 2009;Yang et al., 2014;Yang et al., 2015;Zheng et al., 2016), and Himalaya metallogenic belts Tang et al., 2017). ...
The Bangong–Nujiang metallogenic belt consists of scattered Tethyan oceanic blocks, mainly distributed underneath the margins of the Qiangtang and Lhasa terranes in central Tibet. A new world-class metallogenic belt has been reported in this region recently, based on the geological mapping and ore deposit prospecting over the last two decades. It currently comprises inferred resources of 30 Mt Cu and 500 t Au, together with several Cr–Ni, Fe, and W (Mo) resources, forming a significant potential area for future mineral exploration. These metals are mainly hosted in porphyry copper, skarn copper, skarn iron, orogenic gold, quartz-vein tungsten, and ophitic chromite deposits. The mineral deposits in the Bangong–Nujiang metallogenic belt have been widely recognized in different localities, including the southern edge of the southern Qiangtang block, part of the north Lhasa block, and even part of the central Lhasa block, indicating they were formed in variable geological settings, from the initial opening, subduction, and collision to the extension of the Bangong–Nujiang Ocean. Specifically, five major tectonic events contributed to mineralization, including the stage 1 (240–165 Ma) initial opening of the Bangong–Nujiang Ocean, stage 2 (165–145 Ma) oceanic subduction, stage 3 (145–100 Ma) close of the ocean, stage 4 (100–65 Ma) continent–continent collisional orogenesis, and stage 5 (65–0 Ma) post-orogenesis. At stage 1, Cr–Ni deposits were formed during the initial opening of the ocean; porphyry–epithermal Cu (Au), skarn Fe, and minor orogenic Au deposits were formed at stage 2 and stage 3; a younger pulse of a few porphyry–skarn Cu ± Mo and orogenic Au deposits were formed during stage 4; finally, W(Mo) deposits were generated in stage 5. In general, porphyry Cu systems, orogenic Au, and skarn Cu polymetallic deposits that occurred in the subduction and post-collision settings related W(Mo) deposits have the most potential for future exploration. An in-depth investigation of several scientific problems, such as addressing the tectonic setting, magmatism, and metallogeny of this region and genetic linkage of these deposit preservations to plateau uplift, is essential for the future success of exploration in the Bangong–Nujiang metallogenic belt.
... The Rhodope metallogenic province in NE Greece represents one of the most prospective areas for base, precious, and rare metals in the European part of the Tethyan metallogenic belt, where numerous porphyry and epithermal prospects with an exotic mineralogy and element enrichment have been found (Moritz and Baker 2019;Richards 2015;Voudouris et al. 2019). The northward subduction and slab-retreat of the African plate beneath Eurasia since the Cretaceous initiated intrusive and extrusive calc-alkaline to shoshonitic magmatic activity along the ~ 50 km long NE-SW striking age-progressive Maronia Magmatic Corridor in NE Greece (MMC, Fig. 1a; Jolivet and Brun 2010;Moritz and Baker 2019;Perkins et al. 2018). ...
Porphyry-epithermal veins hosting Re-rich molybdenite and rheniite (ReS2) from the Maronia Cu-Mo ± Re ± Au porphyry in Thrace, NE Greece, provide new insights into the hydrothermal processes causing extreme Re enrichment. Quartz trace element chemistry (Al/Ti, Ge/Ti), Ti-in-quartz thermometry, and cathodoluminescence imaging reveal multiple quartz generations in consecutive hydrothermal quartz-sulfide veins associated with potassic, sericitic, and argillic alteration. Fluid inclusions in different quartz generations indicate that phase separation and fluid cooling are the main ore-forming processes in the porphyry stage (~ 500 – 350 °C), whereas mixing of a vapor-rich fluid with metalliferous (e.g., Pb, Zn, Au) meteoric water forms the epithermal veins (~ 280 °C). These processes are recorded by trace element ratios in pyrite that are sensitive to changes in fluid temperature (Se/Te), fluid salinity (As/Sb, Co/As), and mixing between fluids of magmatic and meteoric origin (Se/Ge). Highly variable intra-grain δ³⁴S values in pyrite record S isotope fractionation during SO2 disproportionation and phase separation, emphasizing the importance of in situ δ³⁴S analysis to unravel ore-forming processes. High δ³⁴S (~ 4.5‰) values of sulfides are indicative of low SO4²⁻/H2S fluid ratios buffered by the local host rocks and mixing of the magma-derived fluid with meteoric water. The formation of Re-rich molybdenite (~ 6600 ppm) is favored by cooling and reduction of a magma-derived, high-temperature (~400 °C), oxidized, and Re-rich fluid triggering efficient Re precipitation in early veins in the potassic alteration zone. The systematic temporal fluid evolution therefore reveals that coeval cooling and reduction of oxidized Re-rich fluids cause extreme Re enrichment at the Maronia porphyry system.
... (Şengör ve ılmaz 1981;Yılmaz, 1990;Yılmaz vd., 1994;Şengör vd., 1993;Genç, 1998;Yılmaz vd., 2001) (Yılmaz vd., 2010;Yiğit, 2012;Bozkaya ve Banks, 2015;Richards, 2015; Çiçek ve Oyman, 2016;Sánchez vd., 2016;Menant vd., 2018;Kuşçu vd., 2019;Çiçek vd., 2021;Kıray, 2021;Kıray ve Cengiz, 2023 (Okay ve Tüysüz, 1999), b) Biga Yarımadası'nın genelleştirilmiş jeolojisini gösteren yer bulduru haritası (Duru vd. 2012;Konak vd., 2016;Ersoy vd., 2017a,b;Aydın vd.,2019'den değiştirilerek). ...
Bu çalışma Biga Yarımadası (KB Türkiye)’nda yer alan Karadoru (Biga, Çanakkale) ve Karaköy (Yenice, Çanakkale) arasındaki Pb-Zn-Cu cevherleşmelerinin jeokimyasını ve kükürt izotop oranlarıile kökenini ortaya koymaya yöneliktir. İncelenen cevherleşmeler, Karadoru, Peynirderesi, Madençeşme (Biga, Çanakkale) ve Karaköy (Yenice, Çanakkale) olmak üzere toplam 4 lokasyonda gözlenmektedir. Bölgenin en alt tektonostratigrafik birimini Karakaya Kompleksi oluşturmaktadır. Karakaya Kompleksinin birimi olan ve başlıca metabazik kayaçları içeren Nilüfer birimi onun üzerinde de kireçtaşları, spilitik bazalt, diyabaz ve arkozik kumtaşlarını kapsayan Hodul birimi yer alır. Karakaya Kompleksine ait birimlerini Oligosen-Miyosen yaşlı Karadoru, Sarıçayır ve Soğucak granitoyidleri kesmektedir. Bölgede yüzlek veren birçok plütonik kütlelerin Karakaya Kompleksi (Nilüfer ve Hodul)’ne ait birimleri kestiği lokasyonlarda skarn zonları gelişmiştir. Karadoru, Sarıçayır ve Soğucak granitoyid kayaçları üzerine Miyosen yaştaki Çan volkanitleri gelir. İncelenen Pb-Zn-Cu cevherleşmeleri Karakaya Kompleksi içerisindeki Karadoru ve Madençeşme lokasyonlarında Nilüfer biriminde (epimetamorfikler), Peynirderesi ve Karaköy (Arapuçandere) mevkiilerinde Hodul birimi (metadiyabazve kristalize kireçtaşı) içerisinde damar şeklinde yataklanmaktadır. Cevherleşmenin mineral parajenezini galen, kalkopirit, sfalerit cevher mineralleri ile pirit, limonit, hematit, malakit, manganoksit, kuvars, kalsit ve klorit oluşturmaktadır. Çalışma alanındaki cevherli zonlardan alınan galen ve pirit numunelerinin δ34S değerleri sırasıyla Karadoru ‰ -3,4 ve ‰-3,9, Karaköy ‰-1,7 ve ‰ -1,6, Peynirderesi ‰ -1,7 ve ‰ -4,0 şeklindedir. İncelenen Pb-Zn-Cu cevherleşmelerinde galenlerde Sb/Bi oranının 0,06-0,34 ppm, piritlerde Co/Ni oranı 1-10 ppm arasında olması, kükürt izotop oranlarının negatif değerlerde olması, cevherleşmenin magmatik hidrotermal kökenli ve I-tipi bir magmatik aktiviteye bağlı olduğunaişaret etmektedir. Buna ek olarak, Pb-Zn-Cu cevherleşmelerinin damar şeklinde epijenetik yataklanması, iz element içeriklerinin (Pb, Zn, Cu, Bi, Sb, Ag, Au, W, As) yüksekliği ve silisleşme, serizitleşme, killeşme ve limonitleşme alterasyonlarının gözlenmesi de cevherleşmenin hidrotermal kökenli olduğunu destekler niteliktedir.
... With the opening and closing of the Neotethys ocean basin, the Tethyan-Eurasian Metallogenic Belt developed as a result of the occurrence of the Alpine-Himalayan orogeny during the Mesozoic-Cenozoic periods [57]. This belt, extending from Southern Europe in the west to the Western Pacific in the east, is known as one of the richest metalproducing belts in the world [58]. Turkey forms a part of the western region of this large magmatic-metallogenic zone and hosts many precious (Au, Ag) and base-metal (Pb, Zn, Cu) deposits. ...
In this study, the facies and degrees of hydrothermal alteration related to the low-sulfidation epithermal Kestanelik Au deposit in the Biga Peninsula metallogenic province are identified through petrographic studies and analysis of geochemical characteristics, such as mass changes, molar element ratios, and alteration indices. The gold mineralization is located in silicified zones containing veins and stockwork veinlets of silica. In the Kestanelik Au deposit, common hydrothermal alteration is mainly found in the Permian-Upper Cretaceous Çamlıca basement metamorphics and the Eocene granodiorite, and less often in the Eocene Şahinli volcanic rocks of the Karabiga Massif on the Peninsula. Based on mineralogical and geochemical studies conducted on altered samples, four different alteration facies are defined as silicic, sericitic, argillic, and propylitic, which show remarkable differences in the behavior of REEs, Si, K, Al, Na, and Ca elements. The hydrothermal fluids that caused alteration in the Kestanelik Au mineralization and host rocks had low REE contents because of REE mobilization. In addition, the kaolinization of feldspars and micas, and the chloritization of biotite and feldspars, may have caused negative Eu anomalies. The characterization of rocks subjected to hydrothermal alteration that are most influenced by diverse K-metasomatism with the largest K gains and losses in Na–Ca is illustrated by molar element ratio plots. Depending on the intensity of K-metasomatism, gold mineralization increases with increasing K trends toward gold ore veins. In the Kestanelik Au field, the argillic, sericitic, and propylitic alteration types from the zones enclosing the Au ore veins are revealed using the Ishikawa alteration index and chlorite–carbonate–pyrite index. Mass changes in the altered rocks indicate that there are gains in Si, K, and Al, and losses in Na and Ca with the increasing intensity of alteration toward the ore veins. The results confirm the presence of silicic and K–metasomatic (sericite and argillic) and propylitic (Fe-rich chloride) alteration zoning extending from the inner regions to the outer regions, which characterize the epithermal ore systems.
... During the subduction stage, acid to intermediate magmatic rocks intruded in the Carpathians, forming world-class porphyry deposits (Cu, Au, Mo, Bi) associated with Au-rich epithermal veins systems (the Bananitic magmatic and metallogenic belt-BMMB). The BMMB is a complex calc-alkaline magmatic arc of Late Cretaceous age that extend over Bulgaria, Serbia, and Romania It hosts a variety of magmatic-hydrothermal Cu, Au, Mo, Zn, Pb and Fe deposits [35,[39][40][41]. ...
The main objective of this manuscript is to collect, classify, and compile all available data about secondary mineral sources of REEs in the South-Eastern Europe (SEE). The material is generated from the extracting and processing sector, that might be possibly transformed in the business process becoming an important raw material for another industry. The management inventory guide will strengthen communication and dissemination efforts and simultaneously contribute to Europe’s self-sufficiency and support transitioning to green and digital technology. Identification of the knowledge gaps associated with secondary sources of REEs in SEE will contribute to connections between all partners being involved at the beginning, during the lifetime of products and at the end of the life cycle, represented with deposit owners, technology developers and potential processors, producers, and potential users. At the investigated area it was found 1835 individual landfills, most of them belonging to waste rocks. The total quantity of all material in SRM is about 3.2 billion tons on an area of about 100 km2. The largest 95 individual landfills were selected as potential prospective landfills, containing about 1600 million tons of material. The estimated total potential of REEs (ΣREE) is more than 200 Kt. The largest quantities are found in landfills for coal fly ash and Cu flotation, which correspond to more than 80% of the ΣREE. Most of the promising sites are located in Serbia and North Macedonia. It has been calculated that the valorisation potential and perspectivity of REE2O3 is about 32.5 billion USD (prices from December 2022). According to the average concentrations of REEs, the most prospective are the red mud dams but their total volume is limited compared to massive amounts of coal fly ash landfills. The REEs content in all type of investigated materials, especially in coal fly ash in North Macedonia is twice as high as in other countries.
... With the opening and closing of the Neotethys ocean basin, the Tethyan-Eurasian Metallogenic Belt occurred as a result of the development of the Alpine-Himalayan orogeny during the Mesozoic-Cenozoic periods [72]. This belt, extending from Southern Europe in the west to the Western Pacific in the east, is known as one of the richest metal-producing belts in the world [73]. Turkey forms a part of the western region of this large magmatic-origin metallogenic zone and hosts many precious (Au, Ag) and base metal (Pb, Zn, Cu) deposits ( Figure 1). ...
This study identifies the facies and degrees of hydrothermal alteration related to the low sulphida-tion epithermal Kestanelik Au deposit in the Biga Peninsula metallogenic province through petro-graphic studies and analysis of geochemical characteristics, such as mass changes, molar element ratios, and alteration indices. The gold mineralization is located in silicified zones containing veins and stockwork veinlets of quartz. These zones are found within the Permian-Upper Cretaceous aged Çamlıca basement metamorphics and Eocene aged Kestanelik granodiorite of the Karabiga Massif on the Biga Peninsula. The mineralization is influenced by tectonic structures such as quartz veins and faults. In the Kestanelik Au deposit, common hydrothermal alteration occurs mainly in the metamorphics and granodiorite, and less often in volcanic rocks. Based on miner-alogical and geochemical studies conducted on altered samples, four different alteration facies were defined as silicic, sericitic, argillic and propylitic, which show remarkable differences in the behaviour of REE, Si, K, Al, Na and Ca elements. The characterization of rocks subjected to hy-drothermal alteration that are most influenced by diverse K metasomatism with the largest K gains and losses of Na-Ca, is illustrated by molar element ratio plots. Depending on the severity of K-metasomatism, gold mineralization rises with increasing K trends towards gold ore veins. In the Kestanelik Au field, the alteration types of argillic, sericitic, propylitic and adularia from the alter-ation zones enclosing the Au ore veins, were revealed by the alteration index and chlo-rite-carbonate-pyrite index. Mass changes in the altered rocks indicate that there are gains in Si, K, Al, and losses in Na and Ca with the increasing intensity of alteration towards the Kestanelik ore veins. The results confirm the presence of silicic and K-metasomatic (sericite and argillic) propylit-ic (Fe-rich chloride) alteration zoning extending from the inner regions to the outer regions, which characterize the epithermal ore systems. It has been revealed from the data obtained in this study that the intensity of potassium metasomatism that occurs in acidic rocks is greater than that found in intermediate and mafic rocks. The hydrothermal fluids that cause alteration in Kestanelik Au mineralization and host rocks had low contents of REE due to REE mobilization, and the kaolini-zation of feldspars and micas, and the chloritization of biotite and feldspars, may cause negative Eu anomalies.
... Tetisin jeodinamik evrimi Türkiye'nin bu günkü jeolojik çeşitliliğinde en önemli katkıyı vermiştir. Özellikle son zamanlarda oluşturduğu depremler nedeniyle önemli bir gündem olan Kuzey Anadolu ve Doğu Anadolu Faylarını içine alan aktif tektoniği (Şekil 1 içindeki alıntı şekil), metalojenik özellikleri bu jeodinamik süreçle, özellikle de Paleotetis ve Neotetis'in gelişim ve kapanması süreçleriyle yakın ilişkilidir [1][2][3] Epitermal yataklar ve çoğunlukla yakın ilişkili oldukları porfiri yataklar; çarpışma orojenik kuşaklarında, yitim sonrasında ve bir çarpışma esnası veya sonrası oluşmaktadırlar [2] (Şekil 4c). Epitermal yataklar çoğunlukla Au-Ag ve Hg-Sb yatakları şeklinde yaygın olarak Türkiye'nin kuzeydoğu Anadolu ve Batı Anadolu bölgesinde, Karadeniz ve Marmara'ya paralel bir zon üzerinde bulunmaktadır [5,31]. ...
... The Tethyan mountain ranges represent the longest continuous orogenic belt on Earth, which extends from northwest Africa and western Europe to the southwest Pacific Ocean (Moritz and Baker, 2019). This fertile metallogenic belt has a wide range of ore deposit types developed in various geodynamic environments, which are the source of a diverse range of commodities extracted for societal benefit (Janković, 1977;Janković, 1987;Janković, 1997;Richards, 2015;Richards, 2016). Bauxite and Ni laterite deposits (Herrington et al., 2016), ophiolite-associated chromite deposits (Çiftçi et al., 2019), sedimentary exhalative and Mississippi Valley-type deposits (Palinkaš et al., 2008;Hanilçi et al., 2019), and deposits associated with surficial brine processes (Helvacı, 2019) are among the ore deposit types that occur within this sector (Moritz and Baker, 2019). ...
This study focuses on the evolution of the Kirazlıyayla volcanic-hosted Zn-Pb ± Cu epi-mesothermal vein-type deposit and its relationship to volcanism in NW Turkey. The Kirazlıyayla area has an extensive variety of geological formations, including the Karakaya, Yenipazar, Fındıcak, Sarısu Volcanics, and Mesudiye. The mineralization that formed within the Sarısu Volcanics at Kirazlıyayla mine area exhibits distinctive features, including the occurrence of crosscutting quartz and sulfide veins and veinlets, forming a network of sulfide-bearing stockworks with locally banded/bedded massive sulfide. Three mineralization phases occur across the alterations. Pyrite crystallization and silicification alteration occurred during the first phase. In the next phase, sphalerite develops with the deposition of the first generation of galena and chalcopyrite occurs along with sericite, kaolinite, and quartz in the phyllic alterations. Dolomite and calcite minerals dominate carbonatization in the third phase, with the second generation of galena and chalcopyrite with tennantite. The δ34S of the sulfides exhibited a range of values from 0.7 to 6.8 ‰VCDT, with an average value of 2.13 ‰VCDT. The presence of igneous rocks in the study area provides evidence for a uniform sulfur source having magmatic signature. The variability in sulfur isotope composition can be observed in intermediate and high-sulfidation ore minerals. The use of oxygen isotope analysis has the potential to facilitate the identification of hydrothermal fluids involved in the formation of ore deposits, which often exhibit a combination of magmatic and metamorphic fluids. The fluid inclusion investigations have shown two-phase liquid-vapor inclusions in both the sphalerite and quartz minerals, which could be categorized as both primary and secondary varieties. The indication of these fluid inclusions inside sphalerite and quartz implies a potential meteoric source and may be attributed to the gradual mixing of fluids responsible for ore formation, which is facilitated by the influx of meteoric water along the pathway of fluid flow. Therefore, these fluid inclusions show magmatic-meteoric mixing, resulting in the creation of low-salinity ore-forming fluids due to the interaction between magmatic fluid and diluted meteoric water, resulting in further mineralization at the late stage of mineralization. Zinc, lead, and copper in hydrothermal fluids may supersaturate under fluid mixing conditions, producing Zn-tennantite and second-generation galena minerals.
In conclusion, the Kirazlıyayla deposit is influenced by a variety of physicochemical conditions associated with volcanism and the transportation of hydrothermal fluids. These fluids penetrate the crust, dissolving metals from nearby rocks, and may circulate and flow towards the surface via the NE-trending faults and fractures in the study area. When these hydrothermal fluids reach zones of lower pressure or temperature, mineralization often occurs, allowing dissolved metals to precipitate out of the fluid and create mineralized veins. Therefore, the volcanism played a significant role, both as a heat source and a mechanism for mobilizing hydrothermal fluids, enhancing the understanding of metallogenesis in NW Turkey.
... Precious metal deposits typically form in areas of active tectonism; hence, likely sources occur mostly within the Alpide-Himalaya-Tethys (Alpide) tectonic belt, between Iberia and the Himalayas (Richards 2015), shown in Figure 7. Exceptions include older gold deposits in Egypt, Nubia and Arabia. The geologically active and topographically uplifted regions of the Alpide belt are antithetic to the geological stability and well-watered alluvium favoured by early urban civilizations in lower reaches of the Euphrates and Tigris rivers, and the Nile and Indus valleys; their metal supplies thus relied on expeditions and trade networks. ...
We have documented more than 200 relative values of gold and silver across almost 3000 years (2500 bce –400 ce ) to establish value benchmarks for essentially pure metal. Our aim is to improve understanding of ancient economies by enabling regional and temporal comparisons of these relative values. First, we establish silver as an early, reliable benchmark for valuing gold of varying purity before implementation of parting. Whilst purity accounted for two to threefold variation in the value of gold, we conclude that availability was more influential. Access to Nubian gold until about 1100 bce seems an important influence on gold-silver value ratios in Egypt and the Near East, which increased significantly following loss of this source. This investigation yields a suite of relative values for essentially pure gold and silver, subdivided by regions and intervals from 2500 bce –400 ce . These will enable future comparisons of precious metal-denominated costs of labour and commodities, including with today.
... The UDMA hosts numerous porphyry-type Cu deposits (PCDs) thought to be associated with mid to late Miocene-Pliocene magmatism. Many authors (Shafiei et al., 2009;Haschke et al., 2010;Asadi et al., 2014;Richards, 2015) propose that PCDs are linked to post-collisional magmatic processes with adakitic characteristics (Asadi, 2018), and that their architecture is largely controlled by intra-arc transform faults induced by oblique collision and extensional structures induced by slab breakoff, slab retreat, or lithospheric delamination (Asadi et al., 2014;Ahmadian et al., 2016). ...
This study presents copper isotope compositions of mineralized whole-rock samples from the Kerman porphyry
copper belt (KPCB) southeast of the Urumieh Dokhtar magmatic arc. Samples for this study were specifically
collected from the Sar Cheshmeh, Meiduk, Iju, SarKuh, Darreh Zar, Bagh Khoshk, and Jebal Barez deposits and
investigated to study the application of Cu isotopes to mineral exploration. While in the leached cap zone of the
deposits, δ65Cu values range between -3.41 to 5.82 ‰ (avg. 0.42 ‰), in the supergene enriched zone of these
deposits the relatively higher δ65Cu content ranges from 5.18 to 8.71 ‰ (avg. 7.17 ‰), and in the hypogene zone,
the intermediate δ65Cu values range from 1.49 to 7.31 ‰ (avg: 4.36 ‰). Most measured δ65Cu values in these
investigated porphyry copper deposit are positive, which indicates the presence of a Cu-enriched zone. In the
enriched leached cap zones, the δ65Cu of the Darreh Zar and Sar Cheshmeh deposits are overall higher relative to
the Iju, Meiduk, SarKuh, and Bagh Khoshk deposits, and these higher δ65Cu values are associated with the highest
Cu grade and tonnage in the Sar Cheshmeh and Darreh Zar deposits. It is therefore plausible to conclude that the
higher δ65Cu value in the leached areas are diagnostic of the high concentration of copper.
These findings are complemented by the presence of Cu(II) carbonates, silicates, and Fe-oxides in each
sample that has resulted in the enrichment of 65Cu, relative to the remnant sulfides with a wider copper isotope
range. In addition, there is a general shift toward higher δ65Cu isotope values relative to the inferred precursor
minerals. The overall apparent weathering and oxidative dissolution is likely to have generated isotopically
heavier fluids and lighter residual minerals. The elevated δ65Cu of the bulk samples from porphyry Cu deposits in
KPCB is consistent with a preferential loss of 63Cu into fluids during the segregation of aqueous fluid–melt. This is
best explained by several pulses of hypogene magmatic fluid which led to repeated enrichment in 65Cu in the
magmatic system. It is plausible to conclude that copper isotope values in these mineralized samples can be used
as an effective exploration tool to identify buried porphyry Cu systems.
... The magmatic evolution of the Urumieh-Dokhtar arc is related to the Neo-Tethys subduction and the continental collision between the Arabian and Eurasian plates, which has led to the creation of diverse and different magmatism along different parts of this belt (Shahabpour, 2005;Agard et al., 2011;Richards, 2015;Karimpour et al., 2021). ...
... The roles of arc magmatism in continental crustal growth (Gill, 1981) and ore formation (Tomkins et al., 2012;Richards, 2015) are well established for the Phanerozoic, but much less so for the Neoproterozoic and Archean, although ~20% of the present continental crust formed during the Neoproterozoic (Stern, 2008). This is mainly due to fewer studies of Neoproterozoic arc magmatic systems and associated ore systems than the younger counterparts to date. ...
We use zircon trace elements and Hf–O isotopes, plus whole-rock chemical and Sr–Nd isotope compositions to investigate the controls on the chemistry of Neoproterozoic arc magmas. The samples are from the gabbrodiorite intrusion of the Gaojiacun mafic-ultramafic complex and from the Tongde diorite batholith of the Panxi Neoproterozoic magmatic belt in the western margin of the Yangtze craton, western China. Zircon U–Pb ages reveal that both intrusions are coeval, emplaced at ~820 Ma. Major element compositions of whole rocks and major silicate minerals indicate that the Tongde batholith formed from more evolved magma than the parental magma for the Gaojiacun intrusion. The mantle-normalized trace element patterns of whole rocks from both intrusions are similar, showing light REE enrichments and pronounced negative Nb–Ta anomalies. The Sr–Nd isotopic compositions of the whole rocks are also similar, plotting within or very close to the mantle array, indicating no to minor contamination with the upper crust. Zircon Hf–O isotopes indicate that the Gaojiacun magma has much higher ƐHf (6.26 ± 0.52) and δ18O (7.0 ± 0.3 ‰) than the Tongde magma (ƐHf = 4.81 ± 0.39; δ18O = 5.7 ± 0.2 ‰). The δ18O values of the Gaojiacun zircons are also higher than the normal mantle (δ18O = 5.3 ± 0.6 ‰). Zircon trace element compositions show that, despite their close spatial association (<10 km), the coeval intrusions have contrasting redox states, with the estimated fO2 values of ΔFMQ+1.0 and ΔFMQ-0.7 for Tongde and Gaojiacun, respectively. The former is within the range of modern arc basalts, whereas the latter is lower than the average value of MORBs. The very low fO2 of the Gaojiacun magma could be due to the presence of subducted oceanic sediments enriched in organic matter (OM) in the source or due to contamination with OM-rich sedimentary rocks in the upper crust. Since such crustal rocks have not been reported for the region, we prefer the former explanation. The preferred model is also supported by Sr–Nd–Hf–O isotopes. The results from this study reveal that both reduced and oxidized magma could be produced simultaneously in a subduction zone.
... Porphyry copper deposits (PCDs) are generally formed during composite collision between continents (Groves and Bierlein, 2007;Richards, 2015;Zheng et al., 2019) with intervening arc terrane (accretionary orogeny) but are rare in the simple collisional tectonic setting without intervening arc terrane (collisional orogeny). In the accretionary orogens, PCDs are mainly formed in the magmatic arcs, which are related to hydrous calc-alkaline arc magmas (>4 wt% H 2 O) and derived from the asthenospheric mantle that had been metasomatized by fluids originated from a subducting slab (Richards, 2003). ...
... The Panagyurishte ore district, Bulgaria, is situated in the Srednogorie zone in the western part of the global Cu-Au-dominant Tethyan-Eurasian Cu-Au metallogenic belt (Bogdanov 1987, Popov et al. 2012, Richards 2015 Targets for further prospecting are porphyry-copper and epithermal gold occurrences associated with silica caps around the explored old mines, which need reassessment as possible targets for Cu and Au exploration. ...
... The Panagyurishte ore district, Bulgaria, is situated in the Srednogorie zone in the western part of the global Cu-Au-dominant Tethyan-Eurasian Cu-Au metallogenic belt (Bogdanov 1987, Popov et al. 2012, Richards 2015. The belt extends eastwards from Europe through Turkey, Asia and Malaysia. ...
A UAV-based survey with a combined RGB and TIR camera was utilized and tested for hydrothermal alteration mapping and targeting for copper and gold mineral exploration in the Vlaykov Vruh Cu-porphyry deposit and Pesovets and Petelovo Cu-Au epithermal systems, Panagyurishte ore district, Bulgaria.
The Golden Quadrilateral of the Apuseni Mountains (Romania) represents the richest Au(-Cu-Te) porphyry and epithermal district of Europe and the Western Tethyan metallogenic belt. The Au(-Cu-Te) mineralization is associated with Neogene calc-alkaline magmatism along graben structures growing during the late stages of the Alpine-Carpathian orogeny. We use zircon petrochronology to study the time-space distribution, sources, composition, and timescales of the Au(-Cu-Te)-mineralizing magmatism and explore its link to regional tectonics. Our own and published U-Pb zircon ages document ore-forming magmatic activity between ~13.61 and 7.24 Ma. In combination with available paleomagnetic data, the new zircon ages corroborate the hypothesis that the magmatism in the Golden Quadrilateral evolved in a tectonic environment dominated by major (up to 70°) crustal block rotation. Hafnium isotope composition of Neogene zircon (εHf between –2 and 10) supports the predominant origin of the magmas from a heterogeneous lithospheric mantle, which may have been fertilized during an earlier Cretaceous subduction event and possibly by concurrent Miocene subduction. Xenocrystic zircon shows involvement of crustal sources resembling European continental basement. Fertility indicators, including Eu/Eu* and oxygen fugacity based on zircon composition, show no systematic correlation with the mineralizing events and/or age. High-precision (isotope dilution-thermal ionization mass spectrometry) U-Pb zircon geochronology demonstrates that the magmatic systems exposed at district scale evolved over less than ~100 k.y. and that durations of hydrothermal mineralization pulses were even shorter.
This study aims to review the Jurassic to Cretaceous tectonic setting of the Sanandaj-Sirjan Zone (SaSZ), the inner part of the Zagros orogen. For many years, the SaSZ was interpreted as a part of the Cimmerian microcontinent carrying a Jurassic magmatic arc to the Neo-Tethyan Ocean. Recently, propagating continental rift and mantle plume models have also been considered for this magmatism without taking into consideration the presence of coeval high-pressure metamorphic rocks and S-type granites predating I- and A-type granites. In the middle part of the SaSZ, the association of high-pressure metamorphic basement rocks and S-type granites suggests a collisional tectonic setting during the Early Jurassic, followed by partial melting by decompression and exhumation.
These phenomena are considered to reflect compressive forces from the collision of the Cimmerian microcontinent with the Turan plate contemporaneous with the opening of the Neo-Tethys Ocean. The heterogeneity between the rheologically stiff and heavy Upper Neoproterozoic to Cambrian basement with arc-related mafic magmatic rocks and weak Permian-Mesozoic cover rocks of the SaSZ controlled the downward motion of the former.
We propose that Early Jurassic intracontinental subduction predates subduction of the Neo-Tethys oceanic lithosphere underneath the SaSZ, and the formation of Jurassic magmatism resulted from plate collision and break-off of the subducted slab of the Paleo-Tethyan Ocean and of its associated former passive margin. The Neo-Tethys subduction and formation of the active continental margin started only during Cretaceous times. The lower mantle Mesopotamia anomaly detected by mantle tomography could represent the subducted Paleo-Tethyan slab.
The timing and extent of sulfide saturation have been suggested as controlling factors in the formation of economically significant porphyry Cu deposits in subduction zone settings. However, details on the sulfide saturation history in post-collisional porphyry systems remain ambiguous. Accordingly, we have characterized the whole-rock geochemistry, including platinum-group elements (PGE), of igneous intrusions in the post-collisional Chongjiang porphyry Cu–Mo–Au deposit (southern Tibet) and utilize this data in conjunction with zircon U–Pb geochronological results and sulfide chemistry to assess the timing of sulfide saturation, the nature and amount of magmatic sulfide produced. The Chongjiang intrusions (monzogranite, biotite monzogranite porphyry, granodiorite, dacite porphyry, and quartz diorite porphyry) and mafic microgranular enclaves (MMEs) have zircon U–Pb ages of 14.2 to 12.8 Ma. Covariations in whole-rock major and trace elements among the Chongjiang intrusions and MMEs, together with similarities in their Sr–Nd and zircon Hf isotope compositions, indicate that they are co-magmatic and crystallized from a juvenile lower crustal melt that mixed with mafic melt derived from the lithospheric mantle; this hybrid melt subsequently evolved via fractional crystallization. Trace-element ratios in zircon and temperature − ∆FMQ estimates of the different intrusions suggest that they all crystallized from oxidized (average ∆FMQ = 1.9–2.6) and water-rich magmas. Palladium contents and Pd/Pt ratios in the Chongjiang igneous intrusions increase with decreasing MgO up to 3.9 wt % MgO, after which they abruptly decrease. The initial increase in Pd/Pt ratios likely results from the fractionation of a Pt-rich mineral (e.g. Pt–Fe alloy). The decrease in Pd contents and Pd/Pt ratios at 3.9 wt % MgO likely results from sulfide saturation during magma evolution, but prior to volatile exsolution, which occurred at approximately 1.4 to 2.4 wt % MgO. The presence of magmatic sulfide inclusions in amphibole and magnetite in samples with 3.9 wt % MgO, and the geochemical compositions of sulfide inclusions suggest that they represented trapped sulfide liquid and intermediate solid solution. Results of Monte Carlo simulations demonstrate that 0.003 to 0.009 wt % magmatic sulfide is required to have fractionated from the magma to explain the decrease in Pd contents at 3.9 wt % MgO. Highly chalcophile elements, such as Pd, will be sequestered by the magmatic sulfide that saturates at depth, decreasing their concentrations in the residual silicate melt, whereas concentrations of the less chalcophile elements, such as Cu, Mo, and even Au, will not be as significantly affected. Consequently, sufficient concentrations of Cu–Mo–Au will remain in the residual melt and, upon reaching volatile saturation, can be transported by the vapor phase to form porphyry Cu–Mo–Au deposits. In the case of the Chongjiang deposit, sulfide saturation was likely triggered by the high pressures and/or depletion of FeO caused by the thick (~70 km) crust beneath the Gangdese belt. This contribution presents evidence of sulfide saturation in post-collisional magmatic systems, and demonstrates that the amount of magmatic sulfide produced is a critical factor in controlling the formation of post-collisional porphyry Cu deposits.
The Taurus Belt, one of the main tectonic belts of Türkiye, is represented by Paleozoic-aged carbonate rocks. Cilbayir and Gokbelen (Silifke/Mersin) barite deposits located in these rocks were subjected to a detailed investigation to determine their geochemistry, stable isotopic composition, mineralogy, and genetic model. The ore zone contains the veins and lenses necessary for barite, calcite, and hematite paragenesis. A barite vein strikes N35°E and dips 15°NW in the fragments of the limestone-shale sequence in the north of Gokbelen. Another ore zone has been located in the north and northwest of Cilbayir, and it is associated with limestones along a fault line striking N30°E. The veins containing barite, calcite, and hematite paragenesis have approximately the same BaO content (Cilbayir, 65.05%; Gokbelen, 64.96%). The rare earth element (REE) composition of barites is extremely poor (ƩREE is less than 10 ppm), while ƩREE in carbonate host rocks ranges between 40 and 45 ppm. The mean δ³⁴S values of Gokbelen and Cilbayir are 36.45‰ and 41.87‰, respectively. The average imports of δ¹⁸OSMOW barites were 12.98 ‰. The Gokbelen barites have an ⁸⁷Sr/⁸⁶Sr ratio of 0.718796, while the Cilbayir barites have a ratio of 0.717845. Mineralization at Cilbayir is consistent with vein type with a mean SrO content of 1.2%. In contrast, samples from the Gokbelen area show characteristics of hydrothermal vein-type formations with significant SrO content (average 1.47%). The integration of mineralogical, geochemical, and stable isotope data allows for a comprehensive interpretation of the origin and evolution of the carbonate-hosted vein-type barite deposits in the Silifke–Mersin region.
The subduction and closure of the vast NeoTethys ocean between the Arabian and Eurasian plates has left numerous ophiolitic traces, the unique position of Iran in its central part is noticeable. The lack of information, right on the border of Iran with Iraq and Turkey, due to security considerations, has so far prevented the overview of this suture zone in the northwestern border of Iran. Adding Gysian ophiolite in southern Urmia as a missing link in this stretch can partially cover this lack of information. Since peridotites of the oceanic crust often undergo retrograde processes during subduction and exhumation to the surface, therefore the study of serpentinites in ophiolites is very important in reconstructing the processes that occurred during the closure of the NeoTethys. A comparative study of whole rock chemistry of serpentinites in the central part of the NeoTethys ophiolites, considering several sectors from Iran (Kamyaran, Marivan and Gysian), Iraq (Penjwin and Mawat) and Turkey (Guleman and Osmanie) in this article, indicates that they belong to subducted serpentinites, whether they were originally formed in the fore-arc environment or the at abyssal oceanic environment. Composition of the serpentinites of the central part of the suture zone is similar to the average global serpentinites which have mostly lizardite/chrysotile. All of them show depletion of Mg resulting sea floor alteration during serpentinization. The mentioned point may be caused to data deviation from abyssal peridotites field. Considering that the transition metals contents the confirmed the above setting. Almost all of the studied serpentinites are from subducted type which indicates refertilization of LILE evidences as a result of rock/fluid interaction through serpentinization.
Upper crustal faults and fractures control a natural thermal and non-thermal fluid
circulation in the Lece andesite complex (LAC) (southern Serbia, Vardar Zone). By exhibiting differential conduit-barrier behavior, regional faults, and associated tensional fractures are key elements to this effective natural geothermal system. The combination of field-based hydrogeological prospecting and structural geology (water-bearing structural lineaments) yields several types of geothermal and cold mineral groundwaters that appear genetically linked to a cluster of fluid conduit-type extensional faults (hydraulic boundaries). The results further show that geothermal fluid production occurs in the naturally fractured and non-stimulated subsurface reservoirs distributed around the volcanic body (LAC). The geothermal reservoir doublets lie along the external perimeter of the LAC, whereas the abutting geological assemblage is composed of peri-volcanic, much older Neoproterozoic-Paleozoic metamorphic rock. The embedded thermal fluids are formed in the near-surface zones that are controlled by abundant fractures, in particular, those occurring within the propylitized and hydrothermally altered subsegment of the Lece volcanic body. The resulting productivity of these composite aquifers is reaching very high values. The study further yielded several of the most important factors controlling the natural geothermal reservoirs: (i) the important effects of the extensional (neo)tectonic activity and their influence on the reservoirs (fractured lithological assemblage); (ii) the subsurface hydrodynamic conditions within the interval characterized by the highest quantitative mixing of the thermomineral groundwaters, including (iii) the physical and chemical properties of the LAC mineral groundwaters. The study underlines structural hydraulic boundaries (including the tectonically maintained permeability) having implications for a better assessment of the ongoing fault zone-related geothermal extraction. It further contributes to the overall hydrogeological potential (quantitative and qualitative).
Craton destruction belongs to the continental evolution. Continental evolution is an important frontier field of geoscience that cannot be explained by classical plate tectonics theory in many aspects. In recent years, a series of major research plans have been set up to explore the formation and development of continents and try to establish a new theoretical system of continental evolution. The Chinese mainland’s geological conditions richly endowed by nature provide a rare natural laboratory for China’s geoscience community to achieve breakthroughs in geoscience theory.
Yerkürenin gelişimi ve şekillenmesi maruz kaldığı jeolojik-jeotektonik olaylarla yakından ilişkilidir. Bu süreçlerle kıtaların hareketi, birleşmesi, parçalanması, yeni mikro kıtaların oluşumu yanında yitim ve dağ oluşumları gibi birçok devasa küresel olaylar meydana gelmektedir. Büyük ölçekli fay hatlarının, fay zonlarının gelişiminde, hatta günümüzde sosyal ve kültürel olayları dahi etkileyen büyük ve küçük ölçekli depremlerin oluşumunda da en önemli unsur yerkürenin maruz kaldığı jeotektonik evrim sürecidir. Tetis okyanuslarındaki Afrika, Arab ve Hindistan Plakalarının birbirine doğru yaklaşması ve akabinde de Avrasya kıtası ile çarpışması günümüzün en önemli kuşaklarından biri olan Tetis kuşağını ve ilişkili metalojeni kuşağını da oluşturmuştur. Bu kuşak Batı Akdeniz’den Çin’e kadar uzanır. Türkiye’nin en belirgin tektonik çatısı, Pontidleri, Anatolid-Torid platformundan ayıran İzmir-Ankara-Erzincan Zonu ve Arap Levhasının kuzey kenarını oluşturan Bitlis kenet zonu bu kuşak içinde yer almaktadır. Günümüz Türkiye coğrafyası, birbirleriyle karmaşık kenet zonları ile ayrılan ve Tetis okyanuslarının kalıntılarını (Paletotetis ve Neotetis okyanusları) temsil eden alt plakalara ayrılmaktadır. Türkiye’nin Jeodinamik evriminde, Pontid yayı ile Anadolu-Torid platformunun İzmir-Ankara-Erzincan Kenet Zonu boyunca çarpışmasıyla Neotetisin kuzey kolunun Geç Paleosen-Eosen aralığında kapanması önemli bir olgudur. Bu süreç aynı zamanda Türkiye’nin Neotektoniğinin ana çatısı belirlemiş olup, önemli deprem üreticisi Kuzey ve Doğu Anadolu Fay Zonlarını’n da sorumlusudur. Bu fay zonlarının gelişim süreçleri aynı zamanda bu zonlarla ilişkili önemli maden yataklarının oluşumuna da katkı vermiştir. Maden yatakları açısından değerlendirildiğinde, Kuzey Anadolu Fay Zonu’nda hidrotermal süreçler Geç Paleosen’de başlamıştır. Kuzey Anadolu Fay Zonu içinde bulunan maden yatakları dikkate alındığında, fay zonunun şekillenişi ve maden yataklarının oluşumunun ilişkisi görülebilmektedir. Biga Yarımadasındaki Kısacık altın cevherleşmesi ve Alakeçi listvenitlerindeki altın zenginleşmesi bu zondaki cevherleşmelere örneklerdir. Bu cevherleşmeler dışında da bu zonla doğrudan ve dolaylı ilişkili birçok maden yatağı söz konusudur. Dolayısıyla yerküreyi şekillendiren ana tektonik olaylar ve bunlardan kaynaklı aktif tektonik hatlar deprem gibi büyük doğal afetleri oluştururken aynı zamanda da önemli birçok doğal kaynakların da oluşumuna katkı vermektedir. İnsanların imkanları ile engellenmesi mümkün olmayan bu devasa jeolojik olayların meydana getirdiği olumlu imkanlardan yararlanırken, doğası gereği etkili olacağı doğal afetlere karşı da önlem alınarak yaşamanı sürdürmek insanoğlunun en önemli önceliklerinden biri olmalıdır.
This article presents tangible geological evidence for coexistence of porphyry copper and epithermal gold systems within single polygenic deposits and provides a paleothermophysical model for their origins. Brief metallogenic analysis of the Southern Caucasus and Northern Iran has shown that such deposits are confined to long-living calc-alkaline island arcs and were formed during their orogenesis. Examples of complex Sonajil (Iran), Gharta, and Merisi (Georgia) deposits are considered. Investigation has shown that for combined porphyry and epithermal ore formation some preconditions are suggested to exist: (i) Source of anomalous energy, which exceeds thermodynamics of the enclosing environment; (ii) Existence of temperature gradient, which determines conventional flows of fluids composed of endogenous and meteoric constituents (proven by rhythmical zoning of ore lodes); (iii) Stability of such conditions for a period of sulfide ore formation. However, such a process of sulfide ore formation cannot explain formation of high sulfidation gold deposits. Mass precipitation of free gold requires phreatic collapse in the ore conduit channel already after formation of hydrothermally altered rocks, and this event results in creation of either hydrothermal breccias, often with jigsaw-fit texture or brecciated vuggy silica where host rocks and hydrothermally altered rocks are cemented by a gold-bearing quartz matrix.
The Relin Mo–W (–Cu) deposit in the northern Sanjiang area is bound to a Late Cretaceous intracontinental porphyry showing variable alteration. Here we present whole-rock chemistry and Sr, Nd, Pb, Li, and B isotope data to constrain the sources of ore-magmas and to understand how magmatic-hydrothermal processes mobilize the ore elements and alter the magmatic rocks. Chemical variations indicate the ore-bearing porphyries reflect two processes: fractional crystallization and late-magmatic alteration. Fresh and weakly altered porphyries are metaluminous to weakly peraluminous, showing I-type affinity. Chemical variation among these rocks can be explained by fractional crystallization. Most of these rocks show narrow ranges of isotopic compositions with –8.6 to –6.6 for εNd80, 0.70660 to 0.71028 for 87Sr/86Sr80, and high 207Pb/204Pb80 (15.57–15.66) and 208Pb/204Pb80 (39.21–39.51) values at 206Pb/204Pb80 values of 17.37 to 18.96. The chemical and isotopic compositions of these rocks indicate that the porphyries represent mantle melts that mixed with partial melts from the Paleoproterozoic crust. Fresh and weakly altered porphyries have uniform δ7Li (–2.3 to 1.5 ‰) and δ11B (–8.0 to –12.0 ‰). The strong sericite alteration of the porphyries resulted in the loss of Na2O and Sr (breakdown of feldspar) and the strong enrichment of the ore elements Cu, Mo, W, and Sn. Porphyries with varying degrees of alteration show large ranges of δ7Li (–6.0 ‰ to 11.4 ‰) and δ11B (–8.0 to –29.2 ‰). The anomalously high δ7Li and low δ11B values of the altered rocks indicate that the intrusions drove the flow of external fluids that altered the magmatic rocks and leached the ore elements W, Mo, Cu, and Sn from the porphyries and possibly the local wall rocks.
Tourmaline is a borosilicate mineral with general formula of XY3Z6[T6O18](BO3)3V3W. Experimental studies demonstrate a wide range of stability for tourmaline-supergroup minerals to record different geological processes. They occur in metamorphic, granitic pegmatites, and clastic sedimentary rocks and are associated with hydrothermal activities. Textural and compositional features of tourmaline can be used as an indicator of environment in which it crystallized. Tourmaline from porphyry deposits generally show a. frequently crystal zoning, b. development from Fe-rich to Mg-rich, and c. total Mg content is ~2 apfu in copper deposits and 1-2 apfu in Au deposits. It is believed that the world-class Dashkasan gold deposit records the transformation of porphyry to low-sulfide epithermal. The Dashkasan gold deposit located in the Kurdistan Province can be a significant region for better understanding the origin and the evolution of ore-forming fluids using chemistry of tourmaline. For the present study, we also tried to apply fluid inclusions data on quartz-tourmaline-pyrite veins from the Dashkasan deposit.
The Goshgarchay Cu‐Au deposit is located in the central part of the northwest flank of the Murovdagh region in the Lesser Caucasus. The Goshgarchay Cu‐Au deposit is associated with Middle Jurassic volcanic and Late Jurassic‐Early Cretaceous high‐K calc‐alkaline intrusive rocks. Mineralization is commonly related to quartz‐sericite‐chlorite alteration dominantly composed of chalcopyrite, gold, sphalerite, pyrite, bornite, hematite, covellite, chalcocite, malachite, and azurite. The Goshgarchay copper‐gold deposit, which is 600 m wide and approximately 1.2 km long, is seen as a fault‐controlled and vein‐, stockwork‐ and disseminated type deposit. The Goshgarchay Cu‐Au deposit predominantly comprises Cu (max. 64500 ppm) and Au (max. 11.3 ppm), while it comprises relatively less amounts Zn (max. 437 ppm), Mo (max. 47.5 ppm), Pb (max. 134 ppm), and Ag (max. 21 ppm). The homogenization temperatures and salinities of fluid inclusions in quartz for stage I range from 380 to 327°C, and 6.9 to 2.6 wt% NaCl eq., respectively. Th and salinities in quartz for stage II range from 304 to 253°C, and 7.6 to 3.2 wt % NaCl eq., respectively. The calculated δ ³⁴ S H2S values (−1.5‰ to 5.5‰) of sulfides and especially the narrow range of δ ³⁴ S H2S values of chalcopyrite and bornite (between −0.07 and +0.7‰) indicate that the source of the Goshgarchay Cu‐Au mineralization is magmatic. Based on the mineralogical, geochemical, fluid inclusion, and sulfur isotopic data, the Goshgarchay Cu‐Au deposit represents a late stage peripheral magmatic‐hydrothermal mineralization probably underlain by a concealed porphyry deposit.
The research conducted to do an analysis of research productivity related to original character (OC) research based on open access journal indexed in Scopus from 2013 to 2022. The methods used in this research is bibliometric. The results of this research found the number of OC research publications in open access journal from 2013 to 2022 shows a dynamic trend. Publication data with the keyword original character with the highest amount of documents is Plos One with 44 documents. CNRS Centre National de la Recherche Scientifique with 90 documents as an affiliation with the most documents. Subject area in the field of arts and humanities dominates with 722 documents. The most occurrences from the graph shows “species” as the most related item with the original character research trend from 2013 to 2022 in Scopus open access journal database.
The Central Tethys realm including Anatolia, Caucuses and Iranian plateau is one of the most complex geodynamic settings within the Alpine-Himalayan belt. To investigate the tectonics of this region, we estimated the depth to magnetic basement (DMB), as a proxy for the shape of sedimentary basins, and average crustal magnetic susceptibility (ACMS) by applying the fractal spectral method to the aeromagnetic data. Magnetic data is sensitive to the presence of iron-rich minerals in oceanic fragments and mafic intrusions, hidden beneath sedimentary sequences or overprinted by younger tectono-magmatic events. Furthermore, a seismically constrained 2D density-susceptibility model along Zagros is developed to study depth extension of structures.
By comparing the DMB with ACMS, we conclude:
High ACMS indicates steep and gentle lineaments that correlate with known occurrences of Magmatic-Ophiolite Arcs (MOA) and low ACMS coincides with known sedimentary basins in the study region such as Zagros. We identify hitherto unknown parallel MOAs below the sedimentary cover in eastern Iran and the SE part of Urima-Dokhtar Magmatic Arc (UDMA). The result allows for estimation of the dip of paleo-subduction zones.
Known magmatic arcs (Pontides and Urima-Dokhtar) have high-intensity heterogeneous ACMS. We identify a 450 km-long buried (DMB >6 km) magmatic arc or trapped oceanic crust along the western margin of the Kirşehır massif from a strong ACMS anomaly. Large, partially buried magmatic bodies form the Caucasus LIP at the Transcaucasus and Lesser Caucasus and in NW Iran. ACMS anomalies are weak at tectonic boundaries and faults. However, the Cyprus subduction zone has a strong magnetic signature which extends ca. 500 km into the Arabian plate.
We derive a 2D crustal-scale density-susceptibility model of the NW Iranian plateau along a 500 km long seismic profile across major tectonic provinces of Iran from the Arabian plate to the South Caspian Basin (SCB). The seismic P-wave receiver function section is used to constrain major crustal boundaries in the density model.
We demonstrate that the Main Zagros Reverse Fault (MZRF), between the Arabian and the overriding Central Iran crust, dips at ~13° angle towards NE and extends to a depth of ~40 km. The trace of MZRF suggests ~150 km underthrusting of the Arabian plate beneath Central Iran. We identify a new crustal-scale suture beneath the Tarom valley separating the South Caspian Basin curst from the Central Iran. The high density lower crust beneath Alborz and Zagros might possibly be related to partial eclogitization of the crustal root at depths deeper than ~40 km.
The Cenozoic magmatism is mainly concentrated in the Alborz magmatic arc, Urumieh-Dokhtar magmatic arc, Central and Eastern Iran. The Western Alborz magmatic arc known as Alborz-Azerbaijan is hosted numerous porphyry-epithermal deposits. It is divided into Ahar-Arasbaran in the north and Tarom-Hashtjin metallogenic province in the south. The Tarom-Hashtjin metallogenic province is
associated with several epithermal mineral systems (Ghasemi Siani and Lentz, 2022) related to Cenozoic magmatism. It consists mainly of intrusive, subvolcanic rocks, as well as volcanic-sedimentary complexes with acidic to intermediate composition. These rocks with calc-alkaline to shoshonitic nature, are predominantly granite, granodiorite, basalt, andesite, dacite, rhyodacite, rhyolite, and related tuffs. Th main goal of the present paper is to review the available data combined with our new data on the granitoids widespread in the area. An attempt is made to present the lithological, geochemical, and geostructural features of the magma generated in Tarom-Hashtjin metallogenic province.
Detailed Pb isotopic maps of the central Andes, based on 345 (163 previously published, 182 new) analyses of ores, volcanic rocks, and their host rocks, elucidate the gross structure of the basement and reveal that several isotopically distinct basement domains are juxtaposed in this region. The data clearly show that most of the Pb in central Andean igneous and ore samples is derived from the local basement, including Pb in ore deposits of the Bolivian tin belt. Some of the isotopic domain boundaries correspond to geologic structures and the residual gravity pattern, as well as to metallogenic boundaries such as the western edge of the Bolivian tin belt.
Abstract
Recent geochemical studies of volcanic rocks forming part of the ophioliteswithin the Zagros andNaien-Baft orogen indicate thatmost of them were developed as supra-subduction ophiolites in intra-oceanic island arc environments. Intra-oceanic island arcs and ophiolites nowforming the Naien-Baft zone were emplaced southwestward onto the northeastern margin of the South Sanandaj–Sirjan Zone, while those now in the High
Zagros were emplaced southwestward onto the northern margin of Arabia. Thereafter, subduction continued on opposite sides of the remnant oceans. The floor of Neo-Tethys Ocean was subducted at a low angle beneath the entire Sanandaj–Sirjan Zone, and the floor of the Naien-Baft Ocean was subducted beneath the Central IranianMicro-continent. The Naien-Baft Ocean extended into North-West Iran only temporarily. This
failed ocean arm (between the Urumieh-DokhtarMagmatic Assemblage and the main Zagros Thrust) was filled by thick Upper Triassic–Upper Jurassic sediments. TheNaien-BaftOcean finally closed in the Paleocene andNeo-Tethys closed in the Early toMiddle Eocene. After Arabia was sutured to Iran, the Urumieh-Dokhtar Magmatic Assemblage recorded slab break-off in the Middle Eocene.
Keywords: Neo-Tethyan ocean; Zagros orogenic belt; Supra-subduction ophiolite; Slab breakoff
India–Asia collision resulted in crustal thickening and shortening, metamorphism and partial melting along the 2200 km-long Himalayan range. In the core of the Greater Himalaya, widespread in situ partial melting in sillimanite+K-feldspar gneisses resulted in formation of migmatites and Ms+Bt+Grt+Tur±Crd±Sil leucogranites, mainly by muscovite dehydration melting. Melting occurred at shallow depths (4–6 kbar; 15–20 km depth) in the middle crust, but not in the lower crust. ⁸⁷Sr/⁸⁶Sr ratios of leucogranites are very high (0·74–0·79) and heterogeneous, indicating a 100% crustal protolith. Melts were sourced from fertile muscovite-bearing pelites and quartzo-feldspathic gneisses of the Neo-Proterozoic Haimanta–Cheka Formations. Melting was induced through a combination of thermal relaxation due to crustal thickening and from high internal heat production rates within the Proterozoic source rocks in the middle crust. Himalayan granites have highly radiogenic Pb isotopes and extremely high uranium concentrations. Little or no heat was derived either from the mantle or from shear heating along thrust faults. Mid-crustal melting triggered southward ductile extrusion (channel flow) of a mid-crustal layer bounded by a crustal-scale thrust fault and shear zone (Main Central Thrust; MCT) along the base, and a low-angle ductile shear zone and normal fault (South Tibetan Detachment; STD) along the top. Multi-system thermochronology (U–Pb, Sm–Nd, ⁴⁰Ar–³⁹Ar and fission track dating) show that partial melting spanned ~24–15 Ma and triggered mid-crustal flow between the simultaneously active shear zones of the MCT and STD. Granite melting was restricted in both time (Early Miocene) and space (middle crust) along the entire length of the Himalaya. Melts were channelled up via hydraulic fracturing into sheeted sill complexes from the underthrust Indian plate source beneath southern Tibet, and intruded for up to 100 km parallel to the foliation in the host sillimanite gneisses. Crystallisation of the leucogranites was immediately followed by rapid exhumation, cooling and enhanced erosion during the Early–Middle Miocene.
The Chilas Complex is a large mafic-ultramafic body closely associated with the Kohistan Arc sequence in the western Himalaya of northern Pakistan. The arc and the Chilas Complex occupy an area of 36,000 km2, bounded on the north and south by major sutures. The arc formed close to the margin of Eurasia in response to the northward subduction of neo-Tethyan ocean lithosphere in Late Jurassic to middle Creta-ceous time, and consists of intra-arc sediments, calc-alkaline volc.anics, and diorite-tonalite-granite plutons. At its base is the Chilas Complex, which extends for more than 300 km and which has a maximum width of 40 km. Most of the complex consists of massive (although locally layered) gabbro-norites, which comprise variable amounts of plagioclase (Ano+m), orthopyroxene (Ery6-4), clinopyroxene (mg = 75-55), magnetite, ilmenite, +quartz, tK-feldspar, thornblende, +biotite, +rare scapolite. In the central part of the complex, near the base, there are minor discordant dikes and intrusive bodies as large as 5 km2 of a dunite-peridotite-troctolite-gabbronorite-pyroxenite-anorthosite association that displays excellent layering, graded bedding, slump breccias, and syn-depositional faults. These rocks contain olivine (Fosa-zr), relatively Mg-rich orthopy-roxene (En r-os), clinopyroxene (mg = 85-67), and calcic plagioclase (Ang&sr)' thornblende, achrome spinel, sn{ +pleonaste, and represent a more primitive magma batch emplaced into the base of the gabbro-norite magma chamber.
Porphyry Cu-Au-Pd±Pt deposits are significant Au resources, but their Pd and Pt potential is still unknown. Elevated Pd, Pt (hundreds of ppb) and Au contents are associated with typical stockwork magnetite-bornite-chalcopyrite assemblages, at the central parts of certain porphyry deposits. Unexpected high grade Cu-(Pd+Pt) (up to 6 ppm) mineralization with high Pd/Pt ratios at the Elatsite porphyry deposit, which is found in a spatial association with the Chelopech epithermal deposit (Bulgaria) and the Skouries porphyry deposit, may have formed during late stages of an evolved hydrothermal system. Estimated Pd, Pt and Au potential for porphyry deposits is consistent with literature model calculations demonstrating the capacity of aqueous vapor and brine to scavenge sufficient quantities of Pt and Pd, and could contribute to the global platinum-group element (PGE) production. Critical requirements controlling potential of porphyry deposits may be from the metals contained in magma (metasomatized asthenospheric mantle wedge as indicated by significant Cr, Co, Ni and Re contents). The Cr content may be an indicator for the mantle input.
Neogene-Quaternary post-collisional volcanism
in Central Anatolian Volcanic Province (CAVP) is mainly
characterized by calc-alkaline andesites-dacites, with subordinate
tholeiitic-transitional-mildly alkaline basaltic
volcanism of the monogenetic cones. Tepekoy Volcanic
Complex (TVC) in Nigde area consists of base surge
deposits, and medium to high-K andesitic-dacitic lava flows
and basaltic andesitic flows associated with monogenetic
cones. Tepekoy lava flows petrographically exhibit disequilibrium
textures indicative of magma mixing/mingling
and a geochemisty characterized by high LILE and low
HFSE abundances, negative Nb–Ta, Ba, P and Ti anomalies
in mantle-normalized patterns. In this respect, they are
similar to the other calc-alkaline volcanics of the CAVP.
However, TVC lava flows have higher and variable Ba/Ta,
Ba/Nb, Nb/Zr, Ba/TiO2 ratios, indicating a heterogeneous,
variably fluid-rich source. All the geochemical features of
the TVC are comparable to orogenic andesites elsewhere
and point to a sub-continental lithospheric mantle source
enriched in incompatible elements due to previous subduction
processes. Basaltic monogenetic volcanoes of
CAVP display similar patterns, and HFS anomalies on
mantle-normalized diagrams, and have incompatible element
ratios intermediate between orogenic andesites and
within-plate basalts (e.g. OIB). Accordingly, the calcalkaline
and transitional-mildly alkaline basaltic magmas
may have a common source region. Variable degrees of
partial melting of a heterogeneous source, enriched in
incompatible elements due to previous subduction processes
followed by fractionation, crustal contamination, and
magma mixing in shallow magma chambers produced the
calc-alkaline volcanism in the CAVP. Magma generation in
the TVC, and CAVP in general is via decompression
melting facilitated by a transtensional tectonic regime.
Acceleration of the extensional regime, and transcurrent
fault systems extending deep into the lithosphere favoured
asthenospheric upwelling at the base of the lithosphere, and
as a consequence, an increase in temperature. This created
fluid-present melting of a fluid-enriched upper lithospheric
mantle or lower crustal source, but also mixing with
asthenosphere-derived melts. These magmas with hybrid
source characteristics produced the tholeiitic-transitionalmildly
alkaline basalts depending on the residence times
within the crust. Hybrid magmas transported to the surface
rapidly, favored by extensional post-collision regime, and
produced mildly alkaline monogenetic volcanoes. Hybrid
magmas interacted with the calc-alkaline magma chambers
during the ascent to the surface suffered slight fractionation
and crustal contamination due to relatively longer residence
time compared to rapidly rising magmas. In this way they
produced the mildly alkaline, transitional, and tholeiitic
basaltic magmas. This model can explain the coexistence of
a complete spectrum of q-normative, ol-hy-normative, and
ne-normative monogenetic basalts with both subduction
and within-plate signatures in the CAVP.
Keywords Post-collisional volcanism � Calc-alkaline �
Andesite � Residence time � Central Anatolian
Volcanic Province � Turkey
The Phanerozoic evolution of the western Tethyan region was dominated by terrane collisions and accretions, during the Variscan, Cimmerian and Alpine cycles. Most terranes were derived from Gondwana and present a similar early Palaeozoic evolution. Subsequently, they were detached from Gondwana and affected by different deformation and metamorphic events, which permit to decipher their geodynamic history. Lithospheric scale peri-Mediterranean transects show the present-day juxtaposition of these terranes, but do not allow to unravel their exotic nature or their duplication. To create a reliable palinspastic model around these transects, plate tectonics constraints must be taken into consideration in order to assess the magnitude of lateral displacements. For most of the transects and their different segments, thousand km scale differential transport can be demonstrated.
Recent exploration in the region of Bazman in SE-Iran led to the discovery of gold mineralization in different prospects. The epithermal gold mineralization at Chahnali prospect is hosted by late Tertiary andesites and dacites which had been affected by a widespread and intense alteration including propylitization, argillitization, and silicification. The propylitization was of regional scale and predated the mineralizing events. A first-stage gold mineralization occurs along a series of N-S to N30E trending tensional structures, mainly quartz veins. Trace amounts of gold can be found in individual quartz veins and stockworks that exhibit colloform banding and cockade textures, typical of open-space filling. Native gold, both visible and refractory ( < 10 mu m) is present, and a considerable portion of it occurs in grains < 5 mu m (first gold stage). Minor quantities of sulfides (mainly pyrite) are associated with this event too. The main gold-forming event, a second-stage gold mineralization is associated with a late-stage brecciation and subsequent silicification, which most likely were produced as a result of sinistral faulting along NNE-trending zones. Visible and refractory gold formed together with base metals,which include galena,chalcopyrite, sphalerite, and pyrite. Locally, weathering has led to the formation of jarosite-type minerals, which may contain very fine-grained gold. The gold mineralization is closely associated with quartz-adularia alteration. Therefore it is of low-sulfidation type and was generated in an epithermal environment. The initial results of a first reconnaissance study in Chahnali prospect indicate a remarkable potential for gold in the Bazman region. Further studies are needed to confirm the economic significance with an estimated gold grades averaging at 3-4 ppm.
Closure of the Neo-Tethyan Ocean in the Turkish sector of the Alpine-Himalayan orogen by ca. 12 Ma was succeeded by deformation of a domain between the Eurasia plate, presently bounded by the North Anatolian fault, and the Arabian indenter. Facets of this deformation comprise the crustal thickening and uplift that produced the Anatolian plateau, the establishment of transform faults, and tectonic escape as Arabia has continued to impinge into the collage of Anatolian terranes accreted by closure of the Neo-Tethys. We have compiled a database of neotectonic paleomagnetic results from Anatolia to analyze this deformation. Large rotations (up to 5 degrees/10,000 yr) of small fault blocks along the intracontinental transform faults but do not extend away from these zones and show that seismogenic upper crust is decoupled from lower continental lithosphere undergoing continuum deformation. Between the transforms, large fault blocks exhibit slower rotation rates (mostly < 1 degrees/100,000 yr), varying systematically across Anatolia. Large counterclockwise rotations near the Arabian indenter diminish westward, becoming zero, and then move clockwise near the limit of tectonic escape. The view that the collage has rotated counterclockwise as a single plate, either uniformly or episodically, during the Neotectonic era is refuted. Instead, deformation has been distributed and differential as the collage adapted to changing tectonic regimes. Crustal extrusion to the west and south has expanded the curvature of the Tauride arc and combined with back-roll on the Hellenic arc to produce the extensional horst and graben province in western Turkey. The latitudinal motions are close to confidence limits but consistent with similar to 800 km of northward motion of Anatolian terranes over 40 m.y., a figure including up to a few hundred kilometers of closure linked to crustal thickening since the demise of the Neo-Tethys.
The Nyingchi complex, forming the eastern segment of the Gangdese magmatic arc, occurs within the southern Lhasa terrane in
south Tibet, and is composed dominantly of plutons and their metamorphosed equivalents. Together with some metasedimentary
units these rocks record multiple Mesozoic and Cenozoic magmatic and metamorphic events during northward subduction of Neo-Tethyan
oceanic lithosphere beneath the Eurasian continent. Petrological and geochronological studies reveal that the Nyingchi complex
experienced intense Paleocene subduction-related magmatism and almost synchronous granulite-facies metamorphism accompanied
by the formation of S-type granites. Subduction-related I-type granitoids show geochemical features typical of continental
magmatic arcs; zircon separates from them yield 206Pb/238U ages from c. 65 to c. 56 Ma, and commonly display positive εHf(t) values ranging from −1·7 to +13·0. The occurrence of magmatic epidote, as well as the syn-intrusion high-grade metamorphism,
indicates that the plutons were emplaced at middle to lower crustal depths within the Lhasa terrane. Associated S-type granitoids
are peraluminous and contain garnet and muscovite; their zircons yield 206Pb/238U ages ranging from c. 66 to c. 55 Ma, and these have distinct but mostly negative εHf(t) values from −18·4 to +2·1. The zircons from the associated metasedimentary rocks include both detrital and metamorphic
types; the detrital zircons yielded variable inherited 206Pb/238U ages ranging from c. 2910 to c. 235 Ma, constraining the maximum depositional age to the Triassic. The metamorphic zircons from the metaplutonic and metasedimentary
rocks yielded ages from c. 67 to 52 Ma. Phase equilibria modeling shows that the Nyingchi complex experienced peak granulite-facies metamorphism and
partial melting under conditions of 800–830°C and 9–10·5 kbar, and then cooled isobarically to c. 700°C in the lower crust at depths of >30 km. We argue that rollback of the flat-subducted Neo-Tethyan oceanic slab during
Early Paleogene times resulted in a contractional orogeny and intrusion of voluminous mantle-derived magmas, which caused
large-scale crustal heating, partial melting and granulite-facies metamorphism within the deep crust of the Gangdese arc.
The Nyingchi complex represents the exposed lower crust of the Gangdese magmatic arc, and links the granulite-facies metamorphism
with silicic magmatism and crustal growth during Paleocene arc accretion.
The wolf pack unites and cooperates closely to hunt for the prey in the Tibetan Plateau, which shows wonderful skills and amazing strategies. Inspired by their prey hunting behaviors and distribution mode, we abstracted three intelligent behaviors, scouting, calling, and besieging, and two intelligent rules, winner-take-all generation rule of lead wolf and stronger-survive renewing rule of wolf pack. Then we proposed a new heuristic swarm intelligent method, named wolf pack algorithm (WPA). Experiments are conducted on a suit of benchmark functions with different characteristics, unimodal/multimodal, separable/nonseparable, and the impact of several distance measurements and parameters on WPA is discussed. What is more, the compared simulation experiments with other five typical intelligent algorithms, genetic algorithm, particle swarm optimization algorithm, artificial fish swarm algorithm, artificial bee colony algorithm, and firefly algorithm, show that WPA has better convergence and robustness, especially for high-dimensional functions.
The Sistan Suture Zone (SSZ) in eastern Iran extends as a N–S trending belt over more than 700 km along the border area between Iran and Afghanistan. The SSZ formed as a result of eastward-directed subduction of a Neotethyan ocean basin beneath the Afghan block and includes a tectonic mélange consisting of disrupted meta-ophiolitic rocks within a low-grade matrix of ultramafic, mafic and pelitic schists. Some mélange blocks were affected by eclogite-, blueschist- and/or epidote amphibolite-facies P–T conditions. Understanding of the petrological and geochronological record of these rocks plays a key role in unravelling the geodynamic evolution of the SSZ. The main aim of the present study was to assess the geological significance of previously published 40Ar/39Ar ages (c. 116–139 Ma) which have not provided robust age constraints for geodynamic reconstructions on a regional scale. For this purpose, samples were collected within a NNW–SSE trending belt spanning a distance of c. 120 km that exposes the major occurrences of high-pressure/low temperature rocks and epidote amphibolites.
Extensive continental collision-related volcanism occurred in Turkey during Neogene-Quaternary times. In central Anatolia, calc-alkaline to alkaline volcanism began in the Middle-Late Miocene. Here we report trace elemental and isotopic data from Quaternary age samples from central and eastern Anatolia. Most mafic lavas from central Anatolia are basalt and basaltic andesite, with lesser amounts of basaltic trachyandesite and andesite. All magma types exhibit enrichment in LILE (Sr, Rb, Ba and Pb) relative to HFSE (Nb, Ta). Trace element patterns are characteristic of continental margin volcanism with high Ba/Nb and Th/Nb ratios. 87 Sr/ 86 Sr and 143 Nd/ 144 Nd isotopic ratios of central Anatolian lavas range between 0.704105-0.705619 and 0.512604-0.512849, respectively. The Quaternary alkaline volcanism of eastern Anatolia has been closely linked to the collision between the Arabian and Eurasian plates. KaracadaˇgKaracadaˇg and Tendürek volcanic rocks are represented by alkali basalts and basaltic trachyandesites, respectively. As expected from their alkaline nature, they contain high abundances of LIL elements, but Tendürek lavas also show depletion in Nb and Ta, indicating the role of crustal contamination in the evolution of these magmas. 87 Sr/ 86 Sr and 143 Nd/ 144 Nd ratios of the KaracadaˇgKaracadaˇg and Tendürek lavas range from 0.703512 to 0.704466; 0.512742 to 0.512883 and 0.705743 to 0.705889 and 0.512676, respectively. Petrogenetic modelling has been used to constrain source characteristics for the central and eastern Anatolian volcanic rocks. Trace element ratio plots and REE modelling indicate that the central Anatolian volcanism was generated from a lithospheric mantle source that recorded the previous subduction events between Afro-Arabian and Eurasian plates during Eocene to Miocene times. In contrast, The KaracadaˇgKaracadaˇg alkaline basaltic volcanism on the Arabian foreland is derived from an OIB-like mantle source with limited crustal contamination. Tendürek volcanism, located on thickened crust, north of the Bitlis thrust zone, derived from the lithospheric mantle via small degrees (1.5 %) of partial melting.
Ecuador consists of terranes having both continental (Chaucha, Tahuin, Loja terranes) and oceanic (Macuchi, Alao, Salado terranes) affinity, which were accreted to the Amazon craton from Late Jurassic to Eocene. Four main magmatic arcs were formed by the subduction of the Farallon/Nazca plate since the Jurassic: a Jurassic continental arc on the western margin of the Amazon craton, a Jurassic island arc (Alao terrane), an early Tertiary island arc (Macuchi terrane), and a middle-late Tertiary continental arc encompassing the terranes of Macuchi, Chaucha, Tahuin, Loja, and Alao after complete assembly of the Ecuadorian crust. Mineral deposits formed during these magmatic arc activities include porphyry-Cu and gold skarn deposits in association with the Jurassic continental arc, polymetallic volcanic-hosted massive sulfide deposits (VHMS) in association with the Jurassic island arc of Alao, Au-Cu-Zn VHMS deposits in association with the early Tertiary island arc of Macuchi, and porphyry-Cu and precious-metal epithermal deposits in association with the middle-late Tertiary continental-arc magmatism on the newly assembled crust of Ecuador (Macuchi, Chaucha, Tahuin, Loja, and Alao terranes). In this study, we have compiled 148 new and 125 previously published lead isotope analyses on Paleozoic to Miocene metamorphic, intrusive, volcanic, and volcanosedimentary rocks, as well as on Jurassic to Miocene magmatic-related ore deposits of Ecuador. Lead isotope compositions of the magmatic rocks of the four main arc events derive from mixing of various sources including mantle, variably enriched by pelagic sediments and/or by a high 238U/204Pb component, and heterogeneous continental crust rocks.
Lead isotope compositions of the Ecuadorian ore deposits display a broad range of values (206Pb/204Pb = 18.3–19.3, 207Pb/204Pb = 15.54–15.74, 208Pb/204Pb = 38.2–39.2), which is as large as the range previously reported for all magmatic-related ore deposits of the Central Andean provinces I and II combined. Ore deposits formed before complete assembly of the Ecuadorian crust through complete accretion of the several terranes (i.e., pre-Eocene) have lead isotope compositions overlapping those of the associated magmatic rocks, suggesting a largely magmatic origin for their lead. In contrast, post-assembly ore deposits (i.e., post-Eocene) have lead isotope compositions that only partly overlap those of the coeval magmatic rocks of the continental arc. In fact, several ore deposits have lead isotope compositions shifted toward those of the basement rocks that host them, suggesting that lead derives from a mixture of magmatic lead and basement-rock lead leached by hydrothermal fluids.
Most Ecuadorian ores have high 207Pb/204Pb values (>15.55), suggesting a dominant continental crust or pelagic sediment origin of the lead. However, we caution against concluding that chalcophile metals (for example, Cu and Au) also have a continental crust origin.
Ore deposits of the different terranes of Ecuador, irrespective of their age, plot in distinct isotopic fields, which are internally homogeneous. This suggests that lithologic factors had an important control on the lead isotope compositions. Ultimately, lead isotope compositions of the ore deposits of Ecuador mirror the isotopic compositions of the rocks of the host terranes and are consistent with the multiterrane nature of the Ecuadorian crust.
Roşia Montană, Romania, is Europe’s largest gold deposit, with a current identifıed resource of ~400 Mt at 1.3 g/t Au and 6 g/t Ag. The deposit is hosted by a Miocene age maar-diatreme complex emplaced into Cretaceous flysch-type sedimentary rocks and intruded by dacite domes. High-resolution 40Ar/39Ar dating of adularia associated with gold-bearing veins suggests a protracted period of episodic mineralization spanning about 500,000 years. The major gold mineral is electrum, associated with pyrite, base-metal sulfıdes, and a variety of Au-Ag sulfosalts and minor tellurides. The overall aspect of the gangue and alteration mineral assemblages, as well as the sulfıde assemblage, is characteristic of intermediate sulfıdation-state epithermal deposits.
Describes the paleogeographical evolution of the Alpine and Himalayan mountain ranges from early Mesozoic times to the late Tertiary. The review concentrates on the agglomeration of its vast orogenic collage, some 90% of which accreted to Eurasia during the Cimmeride evolution. Major worldwide sea-level lowering correlates with times of major collisions in the Tethysides, as do widespread arid episodes in central Eurasia. -K.Clayton
Plate-tectonic movements made the Cretaceous a time of major change in the area of the modern Oman and Zagros Mountains. Neo-Tethys 1 had been created in the Late Permian by the calving of a microcontinent (Anatolia, Sanandaj-Sirjan/Central Iran) along the NE margin of Arabia. In the Late Triassic, a second spreading axis, Neo-Tethys 2 (more readily recognizable in Iran than in Oman) replaced that of Neo-Tethys 1 by the separation of the Central Iran and Sanandaj-Sirjan-Kawr microcontinents.
Neo-Tethys 1 had a passive continental margin during the Triassic and Jurassic as the Afro-Arabian portion of Gondwana moved westward away from the actively spreading oceanic ridge of Neo-Tethys 2. Shallow-marine sediments along the continental margin were the source of carbonate turbidity currents that flowed basinward to the abyssal plain of Neo-Tethys 1 until the early Late Cretaceous, whereas the floor of Neo-Tethys 2 seems to have been starved of coarse sediment in its Oman sector.
Early in the Cretaceous, the South American and Afro-Arabian portions of Gondwana began to separate to create the South Atlantic Ocean. South America continued to move to the west, but Afro-Arabia reversed its sense of motion. The ensuing buildup of horizontal compressional stresses led to an eastward-dipping subduction zone within the Oman sector of Neo-Tethys 2, leading to obduction of the Late Permian to mid-Cretaceous Hawasina Series (deposited in Neo-Tethys 1) and the Semail Nappe, which was generated by back-arc spreading. North of the Dibba Line, subduction also took place within Neo-Tethys 1.
The latest Cretaceous was a time of tectonic adjustment and shallow-marine carbonate sedimentation across the area of the present Oman Mountains and southern Zagros, but the effects of late Maastrichtian subduction in Neo-Tethys 2 are visible in the Inner Makran. Evidence of subduction beneath the northern half of the Gulf of Oman suggests that this process has been more or less continuous over the Makran area until today. Uplift of the Oman Mountains began in the Mio-Pliocene, about the same time as the Zagros Mountains began to form.
The temporal and geochemical evolution of arc magmatism that culminated in porphyry Cu ± Mo ± Au deposit formation has been studied in three separate Neo-Tethyan arc systems in central and eastern Iran, and western Pakistan. Porphyry Cu-Au deposits in the Lut block of eastern Iran formed in the middle Eocene at the end of a period of extensive Paleocene-Eocene volcanism; porphyry Cu-Mo deposits in the Kerman belt of central Iran formed in the middle Miocene at the end of a period of voluminous Eocene-Oligocene volcanism; and porphyry Cu-Au deposits in the Chagai belt of western Pakistan formed in four pulses during the Eocene, early Miocene, middle-late Miocene, and late Miocene-Pliocene, after a prolonged period of arc magmatism that began in the Late Cretaceous (and is still active). In each region, the late porphyry-related magmas are more geochemically evolved and more hydrous (as evidenced by the presence of hornblende phenocrysts) than the preceding volcanic rocks. We suggest that this reflects maturation of the arc magmatic system over a period of tens of millions of years, leading to the generation of more evolved, volatile-rich magmas at later stages of the arc's history. High magmatic water contents are a prerequisite for the shallow crustal emplacement of arc magmas and the subsequent generation of potentially ore-forming subvolcanic magmatic-hydrothermal systems. It is thus suggested that the fertility of arc magmas within a given arc terrane can be assessed by observing the relative timing of plutonic suites (later suites are more prospective), noting the common presence of hornblende or biotite phenocrysts (indicating high magmatic water contents), and through lithogeochemical fingerprinting of magmatic fractionation processes (relatively high Sr/Y and La/Yb ratios, and Eun/Eu* ratios ̃ 1, indicating abundant early hornblende fractionation and suppression of plagioclase crystallization in hydrous magmas).
The following conclusions can be drawn concerning the genesis of the Recsk deposit:
1.
The mineralization belongs to the Paleogene volcanic arc along the Balaton-Darno line.
2.
The main phases of mineralization, culminating with porphyry copper formation, are products of hydrothermal events related to a diorite porphyry intrusion (a
3 stage).
3.
The two younger (post-intrusion) volcanic cycles have resulted in late-stage near-surface mineralization, which is considered to be a product of remobilization.
In comparison with other porphyry copper mineralization it may be suggested that the Recsk deposit has an affinity with the island-arc-type magmatism. It shows similarities with the diorite model in the zoning of the intrusive rocks and the ore distribution. Morphogenetically it may be termed a “conformable” deposit. Its classification was simplified by the completeness of the ore depositional sequence, although the sequence of superimposed ore-forming stages created difficulties for interpretation.
The Triassic orogeny in North Tibet results from interactions between the South China, North China and Qiangtang (North Tibet) blocks during the closure of the Paleotethys ocean. It is mainly composed, from west to east, by the Bayan Har, Songpan-Garzê, and Yidun (or Litang–Batang) terranes. We focus here on the Triassic Songpan-Garzê fold belt and the actual eastern margin of the Tibetan Plateau which is one of the key areas for understanding the tectonic evolution of the Asian continent and the Tibetan Plateau. At least three major deformation phases are recognized in eastern Tibet and southeast of the South China block: a Neoproterozoic phase (1–0.75 Ga) correlated to the assembly and break-up of the Rodinia Continent , a Late Triassic compression event and finally a Tertiary deformation related to the India–Asia collision. The tectonic and geodynamic history of this part of Asia is very complex and often vigorously debated. For example the Triassic compression event in Tibet is usually associated to the Indosinian Orog-eny originally defined in Vietnam but this is probably an oversimplification. Our purpose is to review the various models proposed in the literature and to synthesize the tectonic and geodynamic history of this area. We show that the Songpan-Garzê fold belt is not a typical collisional belt: the triangular shape of the closing oceanic basin as well as the huge volume of accreted sediments did not allow a complete conti-nent–continent collision. Finally, the tectonic inheritance plays a major role in the evolution of the eastern margin of Tibet as most of the major Tertiary tectonic structures in the Longmen Shan are reactivated Paleozoic and Mesozoic faults.
Gold-poor and gold-rich porphyry and epithermal gold-silver deposits of Cainozoic and Cretaceous age in the western Pacific and central and eastern Europe are confined to predominantly andesitic continental margins and island arcs. The arc volcanic rocks overlie a complex non-oceanic basement of stacked nappes, the uppermost of which is often ophiolitic. Andesitic volcanism and the formation of a strato-volcano were followed by the ascent of magma and porphyry copper mineralization. Magmatic degassing caused advanced argillic alteration, which is commonly unmineralized in perched water-tables, but may sometimes host high-sulphidation gold or enargite-gold at deeper levels within the propylitic zone. The onset of extensional stress up to 3 m.y. after the andesitic volcanism allowed meteoric water to circulate to depths of 5km or more, with consequent cooling of an ascending magma body at depth and the development of low-sulphidation epithermal gold mineralization near and immediately above the sub-volcanic basement surface. -from Author
Ecuador consists of terranes having both continental (Chaucha, Tahuin, Loja terranes) and oceanic (Macuchi, Alao, Salado terranes) affinity, which were accreted to the Amazon craton from Late Jurassic to Eocene. Four main magmatic arcs were formed by the subduction of the Farallon/Nazca plate since the Jurassic: a Jurassic continental are on the western margin of the Amazon craton, a Jurassic island arc (Alao terrane), an early Tertiary island arc (Macuchi terrane), and a middle-late Tertiary continental are encompassing the terranes of Macuchi, Chaucha, Tahuin, Loja, and Alao after complete assembly of the Ecuadorian crust. Mineral deposits formed during these magmatic arc activities include porphyry-Cu and gold skarn deposits in association with the Jurassic continental arc, polymetallic volcanic-hosted massive sulfide deposits (VHMS) in association with the Jurassic island arc of Alao, Au-Cu-Zn VHMS deposits in association with the early Tertiary island arc of Macuchi, and porphyry-Cu and precious-metal epithermal deposits in association with the middle-late Tertiary continental-are magmatism on the newly assembled crust of Ecuador (Macuchi, Chaucha, Tahuin, Loja, and Alao terranes). In this study, we have compiled 148 new and 125 previously published lead isotope analyses on Paleozoic to Miocene metamorphic, intrusive, volcanic, and volcanosedimentary rocks, as well as on Jurassic to Miocene magmatic-related ore deposits of Ecuador. Lead isotope compositions of the magmatic rocks of the four main arc events derive from mixing of various sources including mantle, variably enriched by pelagic sediments and/or by a high 238U / 204Pb component, and heterogeneous continental crust rocks. Lead isotope compositions of the Ecuadorian ore deposits display a broad range of values ( 206Pb/ 204Pb = 18.3-19.3, 207Pb/ 204Pb = 15.54-15.74, 208Pb / 204Ph = 38.2-39.2), which is as large as the range previously reported for all magmatic-related ore deposits of the Central Andean provinces I and II combined. Ore deposits formed before complete assembly of the Ecuadorian crust through complete accretion of the several terranes (i.e., pre-Eocene) have lead isotope compositions overlapping those of the associated magmatic rocks, suggesting a largely magmatic origin for their lead. In contrast, post-assembly ore deposits (i.e., post-Eocene) have lead isotope compositions that only partly overlap those of the coeval magmatic rocks of the continental arc. In fact, several ore deposits have lead isotope compositions shifted toward those of the basement rocks that host them, suggesting that lead derives from a mixture of magmatic lead and basement-rock lead leached by hydrothermal fluids. Most Ecuadorian ores have high 207Pb/ 204Pb values (>15.55), suggesting a dominant continental crust or pelagic sediment origin of the lead. However, we caution against concluding that chalcophile metals (for example, Cu and Au) also have a continental crust origin. Ore deposits of the different terranes of Ecuador, irrespective of their age, plot in distinct isotopic fields, which are internally homogeneous. This suggests that lithologic factors had an important control on the lead isotope compositions. Ultimately, lead isotope compositions of the ore deposits of Ecuador mirror the isotopic compositions of the rocks of the host terranes and are consistent with the multiterrane nature of the Ecuadorian crust.
The tectonic framework of China within the wider Asian context, together with tectono-thermal events that have formed the various mineral systems are presented in this chapter. The geological configuration of present-day China is characterised by terranes and provinces that comprise the North China Craton and Tarim Craton amalgamated during the Archaean and Palaeoproterozoic between 3.2 and 1.8 Ga. The east-west aligned (present day coordinates) North China Craton and Tarim cratonic block are framed to the north by orogens of the Central Asian Orogenic Belt (CAOB), which in China include the Tianshan and Altay in the northwest and the Hinggan fold belt to the east. The CAOB terranes are the result of accretionary events, which attained their main configuration following the closure of oceanic seaways, such as the Mongol-Okhotsk ocean. In east-central and southern China are the Yangtze Craton and Cathaysia Block, bordered to the west and southwest by the Himalayan fold belts of the Tibetan region. These terranes were largely affected by a series of tectono-thermal events and strike-slip structures, in the Mesozoic and continuing to present day. A figure showing an overview of the distribution of Phaneorozoic mineral systems associated to these events is presented in this chapter. Large and small rift basins, containing important hydrocarbon resources and sandstone-hosted U deposits, are superimposed on the older terranes.
Basanites and alkali basalts from Mahabad in the West Azerbaijan province of Iran are part of a widespread series of Late Miocene-Quaternary mantle-derived magmas erupted within the Turkish-Iranian orogenic plateau, itself part of the active Arabia-Eurasia collision zone. New elemental and Sr-Nd isotopic results are combined with geophysical and geological constraints to suggest that these lavas formed predominantly by small degrees of partial melting of the thick (>> 100 km) Eurasian lithospheric mantle within the garnet facies. Samples are highly enriched in large ion lithophile elements (LILE) and the light rare earth elements (LREE), up to 600 times chondritic values. They mostly possess negative primitive mantle-normalised Rb, K, Nb-Ta, Zr-Hf and Ti anomalies, with an overall signature that indicates a mantle source metasomatised by fluids or melts derived from crust during continental collision or the Tethyan oceanic subduction that preceded it. Sr-Nd isotopic values are similar to other Quaternary centres in NW Iran; Sr-87/Sr-86 is slightly depleted with respect to Bulk Silicate Earth, at similar to 0.7045, and Nd-143/Nd-144 is slightly enriched, at similar to 0.5127. Crustal contamination does not appear to be an important process in the chemistry of these samples. Possible triggers for melting may include: breakdown of hydrous phases during lithospheric thickening; hydration of the mantle lithosphere by underthrusting of the Arabian passive margin; small-scale sub-lithospheric convection due to a significant thickness gradient in the Zagros lithosphere. Such processes may account for small-volume syn-collisional mantle-derived magmatism elsewhere in regions of thick lithosphere where recent slab break-off or lithospheric delamination cannot be proven.
The Yangla skarn Cu deposit (150 Mt at 1.03% Cu) is located in the central segment of the Jinshajiang metallogenic belt within the Sanjiang (Three Rivers) region, southwest China. Skarn orebodies are mainly developed between different units of Devonian carbonate and quartz sandstone rocks with stratiform-like shapes, or within the contact zone between granitoids and marbles. Re-Os dating of molybdenite intergrowth with chalcopyrite yielded a well-constrained 187Re-187Os isochron age of 232.0 ± 1.5 Ma with a weighted average age of 231.8 ± 1.3 Ma, both coeval with the related intrusions (233.1 ± 1.4 and 231.0 ± 1.6 Ma at 2σ by zircon U-Pb dating) from our previously published work. Field and textural relationships indicate three hydrothermal stages characterized by assemblages of prograde skarn (pre-ore stage), retrograde skarn and Cu-Fe-Mo-Bi sulfides (main ore stage), and Pb-Zn sulfides associated with calcite and quartz (late ore stage), as well as one supergene stage marked by secondary Cu mineralization (malachite and azurite). Skarns contain garnets with andraditic compositions (Ad96 Gr2~3Py0~1) and clinopyroxene (two series: Hd6Di94 and Hd86Di13Jo1) with low Mn/Fe ratios (0.1), typical of Cu skarn deposits worldwide. Three stages of fluid evolution were observed by a detailed fluid inclusion study: (1) Early fluids were trapped under two-phase conditions, as evidenced by the coexistence of brine (homogenization temperatures = 560°- 600°C, average salinity = 49.4 ± 1.7 wt % NaCl equiv, n = 33) and vapor-rich inclusions in pre-ore stage andradite and diopside (trapped at ~600 bars, or a depth of approximately 2 km assuming lithostatic pressure conditions). (2) Main ore stage fluid inclusions in quartz were also trapped under two-phase conditions (boiling), as identified by the coexistence of vapor- and liquid-rich fluid inclusions; liquid-rich inclusions homogenized between 312° and 389°C (average = 350° ± 24.7°C, n = 20), with salinities of 2.4 to 5.6 wt % NaCl equiv (average = 4.2 ± 0.9 wt % NaCl equiv, n = 13) and a depth of ~2 km (~200 bars, hydrostatic pressure conditions). (3) Late ore stage fluids are represented by inclusions in calcite, characterized by homogenization temperatures ranging from 220° to 290°C (average = 249° ± 27°C, n = 14) and salinities between 2.1 and 8.0 wt % NaCl equiv (average = 4.6 ± 1.5 wt % NaCl equiv, n = 11). Sulfur isotope compositions of sulfide minerals (pyrite, chalcopyrite, pyrrhotite, and molybdenite) from the main and late ore stage have a narrow range of δ34S values from -1.9 to 2.6‰, consistent with a magmatic origin. Calcite in the late ore stage has δ13C values ranging from -3.2 to -5.9‰ and δ18O from 7.2 to 18.0‰, distinct from the host-rock marble compositions (δ13C = 1.2-4.3‰, δ18O = 10.8-23.9‰). When corrected for temperature (250°C, estimated from fluid inclusion analysis in calcites), these calcite data correspond to ore fluid δ13Cfluid values of -2.0 to -4.6‰ and δ18Ofluid values of 0.5 to 11.2‰ (clustering at ~10‰), which are consistent with a magmatic origin. Lead isotope compositions of sulfides (206Pb/204Pb = 18.273-18.369, 207Pb/204Pb = 15.627-15.677, and 208Pb/204Pb = 38.445-39.611) are similar to those of the granitic intrusions and sedimentary wall rocks, but distinct from those of basalts (206Pb/204Pb = 18.282-19.133, 207Pb/204Pb = 15.564-15.665, and 208Pb/204Pb = 38.367-38.942) in the mining area. Taken together, these geologic, geochemical, and isotopic data confirm that Yangla is a typical Cu skarn deposit.
The Pulang porphyry copper deposit recently discovered in northwestern Yunnan province, is located at the south end of the Triassic Yidun island arc. To date, 15 mineralized porphyry deposits have been defined in the Pulang area and the copper resource is estimated to exceed 10 Mt. The Pulang deposit, as currently defined, is made up of five ore-bearing porphyry deposits, covering an area of approximately 9 km2. Intermediate acidic porphyritic intrusions composed of quartz-diorite, monzodiorite, quartz-monzonite, and granodiorite are widespread in the Pulang area. The alteration zones identified with the porphyry deposits include silicic, potassium silicate, quartz-sericite, and propylitic zones. The porphyry deposits have hornfels at the contact with slate, sandstone, and andesite. Re-Os ages of molybdenite, and Ar/Ar and K-Ar dating of biotite indicate that the Pulang porphyry copper deposit formed during the Indosinian tectonic episode, with the main ore formation taking place from 216 to 213 Ma (Late Triassic, Norian); however, the whole process of hydrothermal activity, including overprinting, may have extended from 235 to 182.5 Ma.