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(a) Outcrops of the subduction‐accretion complexes, ophiolites, and magmatic arc rocks in western and central Turkey (based on Maden Tetkik ve Arama Genel Müdürlüğü, 2016). (b) Tectonic map of the Eastern Mediterranean‐Black Sea region (Okay & Tüysüz, 1999).
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The İzmir‐Ankara suture represents part of the boundary between Laurasia and Gondwana along which a wide Tethyan ocean was subducted. In northwest Turkey, it is associated with distinct oceanic subduction‐accretion complexes of Late Triassic, Jurassic, and Late Cretaceous ages. The Late Triassic and Jurassic accretion complexes consist predominantl...
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... The southern boundary of the Sakarya Zone, particularly in the Eastern Pontides, is dominated by accretionary complexes of middle Permian, Late Triassic, Jurassic, and Late Cretaceous ages, as well as middle Permian, Jurassic, and Late Cretaceous ophiolites, implying that the southern boundary of the Sakarya Zone formed an active margin at least from the middle Permian to Late Cretaceous with intermittent periods of subduction erosion and accretion of intraoceanic arcs (Pickett and Robertson 1996;Okay and Monié 1997;Okay et al. 2002Okay et al. , 2013Okay et al. , 2020Okay et al. , 2022Topuz et al. , 2014Topuz et al. , 2018 2015; Robertson et al. 2023). The accretionary complexes crop out mostly close to the Izmir-Ankara-Erzincan suture. ...
... The pre-Jurassic rocks of the Sakarya Zone are limited to small inliers beneath Mesozoic and Cenozoic volcanic and sedimentary cover ( Figure 1). The dominant pre-Jurassic basement exposures are made up of (i) Early to Middle Devonian granites intrusive into undated low-to medium-grade metamorphic rocks (Okay et al. , 2006Sunal 2012), (ii) early Carboniferous high T-middle to low P metamorphic rocks (Topuz et al. , 2007(Topuz et al. , 2020Ustaömer et al. 2013), (iii) early to late Carboniferous high-K calc-alkaline I-type granitoids and minor ultramafic-mafic intrusions (Topuz et al. 2010Dokuz 2011;Ustaömer et al. 2012Ustaömer et al. , 2013Kaygusuz et al. 2012Kaygusuz et al. , 2016Karslı et al. 2016;Gücer et al. 2016), (iv) upper Carboniferous-lower Permian sedimentary rocks and minor early Carboniferous rhyolites (Okay and Leven 1996;Çapkınoğlu 2003;Dokuz et al. 2017), and (v) Permo-Triassic low-to medium-grade metabasite-marble-phyllites (Pickett and Robertson 1996;Okay and Monié 1997;Okay et al. 2002Okay et al. , 2020Okay and Göncüoğlu 2004;Topuz et al. , 2014Topuz et al. , 2018Robertson and Ustaömer 2012). These basement rocks can be divided mainly into two domains such as (i) a mainly Devonian-Carboniferous continental domain and (ii) Permo-Triassic accretionary complexes. ...
The Sakarya Zone (northern Turkey) is characterized by the emplacement of voluminous granitoids during the late Carboniferous. In this study, we present geological, U-Pb zircon age, elemental abundance and Sr-Nd-Pb isotopic data on two highly evolved Carboniferous granite bodies within the Early to Late Jurassic volcaniclastic rocks in the Şiran region. The largest body forms a roughly E-W trending ~30 km long and 0.5–2.5 km wide stripe the southern boundary of which is a southvergent thrust, and the other one a subcircular outcrop, ~5 by ~3 km, unconformably overlain by Lower Jurassic volcaniclastic rocks. Their emplacement ages are constrained by LA-ICP-MS U-Pb zircon dating to 310–313 ± 7 Ma (2, late Carboniferous). The granitic rocks consist of quartz, microperthitic K-feldspar, plagioclase and minor biotite, and are characterized by highly evolved compositions with high concentrations of SiO2, Na2O, K2O and Ba, and low concentrations of TiO2, Fe2O3*, MgO, CaO, P2O5 and Sr. Geochemical characteristics indicate a highly fractionated high-K calc-alkaline peraluminous I-type affinity. Chondrite-normalized rare-earth element (REE) patterns are slightly fractionated, with light REEs enriched with respect to middle and heavy ones, and showing variable negative Eu anomalies. On the N-MORB-normalized multi-element variation diagrams, samples display negative anomalies of Ba, Nb, Sr, P, Zr, Eu and Ti, and positive anomalies of K, and Pb. Initial 87Sr/86Sr and Nd values are 0.70432–0.70610 and -6 to -11, respectively, similar to other Carboniferous high-K calc-alkaline granites and mafic-ultramafic intrusions in the region. The compositional characteristics of the Şiran granites can be explained mainly by fractional crystallization involving hornblende, plagioclase and biotite and without the involvement of significant amounts of garnet. There is no need to invoke magma mixing and/or melting of a heterogeneous source to account for the geochemical variation. We propose that the late Carboniferous granites formed by remelting of middle- to high-K calc-alkaline mafic rocks at lower crustal depths, followed by extensive fractionation at the upper crustal depths. A thorough review of data from the literature reveals that highly fractionated granites constitute a significant component of the late Carboniferous granites in the Eastern Pontides.
... The early Carboniferous high-temperature, middle-to low-pressure metamorphic units comprise metasedimentary rocks mainly of late Neoproterozoic to early Paleozoic protolithic ages and acidic to ultrabasic metaigneous rocks with Ordovician to early Carboniferous igneous crystallization ages (e.g., Dokuz et al., 2022;Karsli et al., 2020;Topuz et al., 2020). The Permo-Triassic accretionary complexes include (1) greenschist-blueschistfacies and epidote-amphibolite-facies metamorphic rock assemblages, consisting of metabasite, marble, phyllite, and minor metachert and serpentinite (the Lower Karakaya Complex), and (2) non-metamorphic to very low-grade sand-stone, basalt, and limestone (the Upper Karakaya Complex; Pickett and Robertson, 1996;Okay et al., 2002Okay et al., , 2020Okay and Göncüoğlu, 2004;Topuz et al., 2004aTopuz et al., , 2014Topuz et al., , 2018Robertson and Ustaömer, 2012). Ar-Ar phengite dating on the Lower Karakaya Complex gave metamorphic ages ranging from 262 Ma to 195 Ma (middle Permian to earliest Jurassic; Okay and Monié, 1997;Okay et al., 2002Okay et al., , 2020Topuz et al., 2004aTopuz et al., , 2014Topuz et al., , 2018. ...
... The Permo-Triassic accretionary complexes include (1) greenschist-blueschistfacies and epidote-amphibolite-facies metamorphic rock assemblages, consisting of metabasite, marble, phyllite, and minor metachert and serpentinite (the Lower Karakaya Complex), and (2) non-metamorphic to very low-grade sand-stone, basalt, and limestone (the Upper Karakaya Complex; Pickett and Robertson, 1996;Okay et al., 2002Okay et al., , 2020Okay and Göncüoğlu, 2004;Topuz et al., 2004aTopuz et al., , 2014Topuz et al., , 2018Robertson and Ustaömer, 2012). Ar-Ar phengite dating on the Lower Karakaya Complex gave metamorphic ages ranging from 262 Ma to 195 Ma (middle Permian to earliest Jurassic; Okay and Monié, 1997;Okay et al., 2002Okay et al., , 2020Topuz et al., 2004aTopuz et al., , 2014Topuz et al., , 2018. The metaophiolitic fragments record early to middle Permian igneous crystallization ages (274-263 Ma;Topuz et al., 2018;Okay et al., 2020). ...
... Ar-Ar phengite dating on the Lower Karakaya Complex gave metamorphic ages ranging from 262 Ma to 195 Ma (middle Permian to earliest Jurassic; Okay and Monié, 1997;Okay et al., 2002Okay et al., , 2020Topuz et al., 2004aTopuz et al., , 2014Topuz et al., , 2018. The metaophiolitic fragments record early to middle Permian igneous crystallization ages (274-263 Ma;Topuz et al., 2018;Okay et al., 2020). The metabasic and basaltic rocks in both the Lower and Upper Karakaya complexes exhibit mainly anorogenic alkaline affinities similar to those found in seamounts, which suggests seamount accretion during the Late Triassic (Pickett and Robertson, 1996;Sayit and Göncüoğlu, 2009). ...
The Sakarya Zone of northern Turkey contains a well-preserved Early–Middle Jurassic and Late Cretaceous submarine magmatic arc constructed over pre-Jurassic bedrocks that are considered to be the eastward extension of the Armorican Terrane Assemblage in Europe. In this study, we present U-Pb-Hf isotopic data from the detrital zircons of middle Permian and Lower Jurassic sandstones to reveal episodes of Paleozoic–early Mesozoic magmatic flare-ups. Detrital zircon ages, together with data from the literature, define three major age groups at 400–380 Ma, 326–310 Ma, and 250–230 Ma, which indicates three distinct magmatic flare-ups. In addition, there are minor age clusters at 460–430 Ma and 215–195 Ma. Initial εHf values of the detrital zircons indicate significant juvenile input during the Triassic flare-up, the involvement of significantly reworked crustal material during the late Carboniferous magmatic flare-up, and both juvenile and reworked crustal material during the Middle Devonian magmatic flare-up. Within the pre-Jurassic continental basement rocks of the Sakarya Zone, the late Carboniferous igneous rocks are well documented and most voluminous, and the Middle Devonian rocks are known locally, while the Triassic igneous rocks—apart from those in Triassic accretionary complexes—are hardly known. Because the Sakarya Zone is a Gondwana-derived continental block that was later involved in the Variscan and Alpine orogenies, these magmatic flare-ups cannot be explained by subduction-related processes along a single subduction zone. We propose that the Sakarya Zone rifted from the northern margin of Gondwana during the Late Ordovician– Silurian, the Devonian magmatic flare-up (400–380 Ma) was related to the southward subduction of the Rheic Ocean beneath the Sakarya Zone during its northward drift, the late Carboniferous magmatic flare-up (326–310 Ma) occurred following the collision of the Sakarya Zone with 63 Laurussia, and the Triassic flare-up (250–230 Ma) resulted from northward subduction of the Tethys Ocean beneath the Sakarya Zone. Comparison with data from the literature shows that the Triassic and late Carboniferous magmatic flare-ups are also characteristic features of neighboring Armorican domains, such as the Balkans and the Caucasus; however, the Middle Devonian flare-up appears to be restricted to the Sakarya Zone. Along with the late Carboniferous flare-up, the Late Ordovician–Silurian flare-up, which is locally recorded in the Sakarya Zone, is typical of the Armorican Terrane Assemblage as a whole.
... While the new rutile U-Pb age from the eclogite sample constrains the oldest subduction-related timing in the Iranian NeoTethyan region to date, it represents the closest time lagged after the subduction initiation with respect to previous studies (Ahadnejad et al., 2011;Davoudian et al., 2016). Unlike the records in Iran, Early Jurassic ophiolites and accretionary complexes are well documented in Turkey, to the west of Iran, along the strike (Topuz et al., 2013;Okay et al., 2020). The geology in Turkey would help the correlation of the Jurassic subduction zone along the southern Eurasian margin, in southern Iran with the nearby region. ...
... The Anatolian microplate's development is characterized by continental fragments separated by branches of the Paleoand Neo-Tethyan oceans that collided and ultimately combined by the Late Cretaceous-Eocene. These exposures of ophiolitic and high-pressure/low-temperature (HP/LT) rock assemblages identify suture zones (Fig. 4.5; e.g., Şengör & Yılmaz, 1981;Okay, 2008;Moix et al., 2008;Okay & Tuysuz, 1999;Pourteau et al., 2016;Okay et al., 2020). This section describes the evidence of ancient subduction zones that may be linked to or may have influenced the development of the Hellenic arc. ...
... The Sivrihisar Massif in the eastern portion of the TavŞanlı has eclogite, blueschist, and Barrovian sequences (Gautier, 1984;Seaton et al., 2009). Paleocene-Eocene ages from the TavŞanlı zone granites mark the timing of the closure of the IAESZ (e.g., Okay et al., 2020). ...
The Hellenic arc, where the African (Nubian) slab subducts beneath the Aegean and Anatolian microplates, is a type-locality for understanding subduction dynamics. The subducting African slab is the driver for extension in the Aegean and Anatolian microplates and plays a significant role in accommodating the Anatolian microplate's westward extrusion. The Hellenic arc subduction zone initiation (SZI) age is central for deciphering ancient mantle flow, how plate tectonics is maintained, and mechanisms that triggered the onset of subduction. The SZI for the Hellenic arc is debated. A Late Cretaceous-Jurassic SZI age is proposed using tomography and timing of obducted ophiolite fragments thought to be related to the system. Alternatively, a Late Cenozoic (Eocene-Pliocene) SZI is proposed using the analysis of topography combined with estimates of slab age and depth, paleomagnetism, the timing of metamorphism, volcanic activity, and timing of sedimentation within its accretionary wedge. The younger SZI age is consistent with an induced-transference model, where a new subduction zone initiates following the jamming of an older one. The older SZI suggests induced-transference fails, and a single subduction zone persists. The presence of a long-lived subduction zone has implications for characterizing Earth's mantle dynamics and how plate tectonics operates.
... Interbedded mudrocks, siltstones and volcaniclastic sandstones contain Albian (108-101 Ma) detrital zircons . The mass-transport unit, of inferred Coniacian age, is unconformably overlain by Santonian siltstones and marls (İncirli Formation) and then passes into shallow-marine Campanian-Maastrichtian(?) carbonates with rudist bivalves (Rojay and Süzen 1997;Okay et al. 2020). ...
The classic Neotethyan Ankara Melange formed within the Triassic-Eocene İzmir-Ankara-Erzincan ocean (‘N Neotethys’), bordered in central Anatolia by the Kırşehir and Tauride-Anatolide continental units to the south and by the discontinuous Sakarya continent to the northwest. Farther north, the separate Intra-Pontide ocean probably remained partly open until the early Cenozoic. The Neotethyan Ankara Melange developed via phases of intra-oceanic accretion (mainly pre-Aptian), initial continental accretion (i.e. Coniacian (?)), arc magmatism (Upper Cretaceous) and continent-continent collision (Maastrichtian-Early Eocene). Variably dismembered ophiolitic rocks of Early-Middle Jurassic age within the Ankara Melange formed by supra-subduction zone (SSZ) spreading above a generally northward-dipping subduction zone. Volcanic-sedimentary lithologies of Triassic-Cretaceous age represent fragments of oceanic crust including variably sized oceanic seamounts. The oceanic volcanics and sediments accreted from the downgoing plate, whereas the ophiolites represent fragments of the overriding plate. The main driver of accretion in the Ankara area was collision of a large Upper Jurassic-Lower Cretaceous oceanic seamount (probably plume related) and its capping carbonate platform, with Middle-Late Jurassic fore-arc oceanic lithosphere. Intra-oceanic arc and proximal-distal fore-arc basin units developed above the accretionary complex and within remnant Neotethyan ocean to the north during the Upper Cretaceous. After docking with the Sakarya continent, the Ankara Melange was transgressed by continental margin fore-arc and syn-collisional foreland basin sediments (Campanian-Early Eocene). Comparisons with Neotethyan melanges across Anatolia to the Caucasus indicate exceptional development in the type Ankara area.
... The presence of such an oceanic domain is evidenced by the widespread Permo-Triassic accretionary complexes with Middle Permian ophiolite fragments in the Sakarya Zone (Pickett and Robertson 1996;Okay and Monié 1997;Okay et al. 2002;Okay and Göncüoğlu 2004;Topuz et al. 2004, 2014Robertson and Ustaömer 2012. These Middle Permian ophiolite fragments in the Permo-Triassic accretionary complexes were dated by U-Pb zircons as 263 and 274 Ma (Topuz et al. 2018;Okay et al. 2020). Despite the widespread presence of the Permo-Triassic accretionary complexes along the Sakarya Zone, a related Permo-Triassic magmatic arc has not been described. ...
... Okay and Nikishin 2015). In contrast to Iran and further east, the Palaeo-and Neo-Tethyan oceans are not distinct oceanic domains in northern Turkey, as the Permo-Triassic, Early to Late Jurassic and Late Cretaceous accretionary complexes occur next to each other without any interweaving continental domain (Okay et al. 2002(Okay et al. , 2013(Okay et al. , 2020Topuz et al. 2013). In Iran, it is commonly accepted that the Palaeo-Tethys was closed by the latest Triassic (e.g. ...
The Istanbul Zone (NW Turkey) forms the eastward extension of Avalonia and was subjected to deformation, uplift and erosion for a time period of 40–50 Ma following the collision with the Sakarya Zone during Early to Late Carboniferous. This paper deals with the petrology and age of the volumetrically minor basic and acidic volcanism at the lowermost horizons of Middle Permian continental red beds, which are overlain by Lower Triassic marine sedimentary rocks in the Kocaeli Peninsula. The volcanic activity is represented mainly by amygdaloidal basalt, rhyolite and minor trachydacite. The amygdaloidal basalt was derived from near-primary middle-K calc-alkaline mantle melts with negligible crystal fractionation. On the other hand, the rhyolite and trachydacite compositionally resemble A2-type rhyolites and underwent low-pressure crystal fractionation as indicated by the presence of a significant Eu anomaly. Initial ɛNd values of amygdaloidal basalt range from 0.0 to 1.5 and those of rhyolite-trachydacite are between −0.4 and −3.4. Amygdaloidal basalt and rhyolite-trachydacite are not directly related to each other by crystal fractionation. Amygdaloidal basalt probably represents the product of the near-primary mantle melts from low-degree melting of a spinel peridotitic source, and the rhyolite-trachydacite originated from highly-fractionated products of basic magmas that are slightly more alkaline than amygdaloidal basalt. However, basic and intermediate products of alkaline basic magmas are unknown in this region to date. U-Pb dating of zircons from a rhyolite sample yielded an igneous crystallization age of 261 ± 3 Ma (2σ), suggesting that the date of deposition of the continental red beds goes back to the latest Middle Permian. Based on the transgressive nature of the Permian-Triassic sequence that starts from the Middle Permian continental red beds and grades into Lower Triassic marine deposits, we suggest that the volcanism likely occurred in an extensional setting. This extension was concurrent with the northward subduction of the Palaeo-Tethys beneath the Sakarya and Istanbul zones after the Variscan orogeny. Therefore, the latest Middle to Late Permian volcanism might have occurred during the initial stage of a back-arc extensional setting.
... with ∼750 km of intra-oceanic extension in Albian-Cenomanian times (van Hinsbergen et al., 2020). In contrast, only the supra-subduction zone ophiolite (associated with ∼750 km of intra-oceanic extension) at and west of the longitude of the Central Sakarya basin has been identified within the İzmir-Ankara suture zone and throughout the Anatolide-Tauride Block (e.g., Collins & Robertson, 1997)-more consistent with flat slab subduction along a single intra-oceanic convergent margin (e.g., Okay et al., 2020). ...
... Closure of the ∼1,000 km wide İzmir-Ankara Ocean in Western Anatolia was followed by collision between 80 and 60 Ma (e.g., Ballato et al., 2011;Cavazza et al., 2012;Gülyüz, 2020;Gülyüz et al., 2019;Mueller et al., 2022;Okay et al., 2020). At this juncture in the region's geodynamic evolution, both the single and double subduction zone models are more or less identical. ...
... Eocene Mihalgazi Formation describes a ∼1.5 km thick section of predominantly terrestrial strata within the Sarıcakaya basin(Figures 2 and 3;Mueller et al., 2019;Şahin et al., 2019;Okay et al., 2020). The Mihalgazi Formation was deposited prior to 51 Ma and after 47 Ma. ...
The number of subduction zones that facilitated the northward translation of the
Anatolide-Tauride continental terrane derived from Gondwana to the southern margin of Eurasia at the longitude of western Turkey is debated. We hypothesized that if two north dipping subduction zones facilitated incipient collision in western Turkey, a late Cretaceous arc would have formed within the Neotethys and along the southern margin of Eurasia. To determine if an island arc formed within the Neotethys we investigated the sedimentary record of the Central Sakarya basin, which was deposited along the southern margin of Eurasia from 85 to 45 million years ago. Detrital zircon deposited within the lower levels of the Central Sakarya basin (the Değirmenözü Formation) are associated with south to north-directed paleocurrents and exhibit a unimodal late Cretaceous age peak sourced from isotopically juvenile mantle melts. Zircon maximum depositional ages from the Değirmenözü Formation cluster between 95 and 90 Ma and are 5–10 Myr older than biostratigraphic depositional ages. Between 95 and 80 Ma, a 12-unit shift from mantle to crustal derived εHf values occurs in the overlying Yenipazar Formation. We explain the absence of Paleozoic, Eurasian-sourced detrital zircon, the rapid shift from mantle to crustal derived εHf values, and lag time in terms of passive margin subduction within an isolated intra-oceanic subduction zone, whose island arc was reworked from south to north into the Central Sakarya basin during incipient collision. Thus, widely outcropping late Cretaceous plutonic rocks within Eurasia must have belonged to an additional convergent margin.
... Genus represented by 32 described and many more still undescribed species. It is distributed from the northwestern part of Asia Minor (in general, north of the Izmir Ankara suture which is treated as part of the boundary between Laurasia and Gondwana (Okay et al. 2020)) in the east through the greater part of the Balkan Peninsula to the foothills of southeastern Alps on the west. A species from Cyprus (based on a juvenile specimen) seems to belong to this genus. ...
A revised composition of the family Sironidae is given. Two North American genera, namely Holosiro Ewing, 1923 and Neosiro Newell, 1943, are resurrected, one new genus, Arhesiro gen. nov., a subgenus, Tillamooksiro sbg.
nov., and two new species, Holosiro ewingi sp. n. and Neosiro (T.) martensi sp. n. are described. Diagnostic characters
of Cyphophthalmi families are presented and discussed.
... The second area is the Haymana basin, which shows a similar stratigraphy as the Central Sakarya Basin (Ünalan et al. 1976;Okay and Altıner 2016). The detrital zircon data from the Upper Cretaceous sandstones from the Haymana Basin are largely taken from Okay et al. (2019Okay et al. ( , 2020 with one new sample (8890) from which we report 95 concordant ages out of 116 analyses. The third area is in the Central Pontides, where we use detrital zircon ages from the seven Upper Cretaceous sandstones reported by Akdoğan et al. (2019). ...
We report detrital zircon ages from the Upper Cretaceous (Campanian–Maastrichtian) turbiditic sandstones from the Pontides and the Anatolide–Tauride Block, which were located on opposite margins of the Tethys ocean during most of the Paleozoic and Mesozoic. The large data set includes both published and new detrital zircon ages from the Upper Cretaceous Pontide sandstones (2730 zircon ages from 26 samples) and new detrital zircon ages from the uppermost Cretaceous Bornova Flysch of the Anatolide–Tauride Block (378 ages from five samples). Phanerozoic detrital zircons from the Upper Cretaceous sandstones of the Pontides are predominantly Late Cretaceous (56%) followed by Carboniferous (7.9%), Devonian (5.3%), Jurassic (3.1%) and Triassic (2.9%). In contrast, there are no Cretaceous and Jurassic detrital zircons in the uppermost Cretaceous Bornova Flysch, and the Phanerozoic detrital zircon populations are mainly Carboniferous (41.3%), Triassic (7.1%), Permian (6.9%) and Devonian (5.3%). The absence of Cretaceous and Jurassic zircons in the Bornova Flysch shows that there was no sediment transport between the Pontides and the Anatolide–Tauride Block during the latest Cretaceous (75–70 Ma); it also shows that the latest Cretaceous – Paleocene deformation of the Bornova Flysch Zone predates the collision between the Pontides and the Anatolide–Tauride Block, and is associated with ophiolite obduction. The dominance of Carboniferous detrital zircons in the Bornova Flysch Zone underlines that Carboniferous magmatic activity in the Anatolide–Tauride Block, and hence on the northern margin of Gondwana, was more significant than hitherto recognized.
... Akdoğan et al., 2021;Okay et al., 2006;Okay and Topuz, 2017;Topuz et al., 2010;Ustaömer et al., 2012Ustaömer et al., , 2013. The southern boundary of the Sakarya Zone is delimited by the Izmir-Ankara-Erzincan suture which represents the trace of a long-lived Paleozoic to earliest Cenozoic oceanic domain (Okay et al., 2020;Topuz et al., 2013). ...
This study deals with the age and petrogenesis of mafic-ultramafic intrusions ranging in size from a few meters to 10 km within the Early Carboniferous high-grade gneisses of the Pulur Complex in the Eastern Pontides. The intrusions comprise dunite, wehrlite, gabbronorite, leucogabbro, anorthosite and ilmenite-bearing gabbronorite of cumulus origin, and are crosscut by dikes of ilmenite-bearing gabbronorite, leucogranite and microdiorite. U-Pb dating on zircons from gabbronorite, anorthosite and leucogranite yielded igneous crystallization ages of 322–326 Ma, indicating that the intrusions were emplaced ca. 5–7 Ma after the peak of high-grade metamorphism, and form part of the Late Carboniferous high-volume magmatism in the region. In most cumulate rocks, Cr-Al spinel, olivine and plagioclase were early crystallizing phases, followed by orthopyroxene, clinopyroxene and hornblende. Whole rock geochemical data suggest that wehrlite, gabbronorite, leucogabbro and anorthosite stem from a common magma, and ilmenite-bearing gabbronorite and dikes of leucogranite and microdiorite from different magmas. Application of mineral/melt partition coefficients to trace element compositions of clinopyroxene and hornblende in cumulate rocks suggests that the main cumulate body was derived from middle- to high-K calc-alkaline basic melts, and relatively late ilmenite-bearing gabbronorites from hypersthene-normative Ca-rich melts. All the rock types display radiogenic Sr and Pb isotopic signatures, and unradiogenic Nd isotopic ratios, which are indistinguishable from those of the coeval voluminous high-K calc-alkaline I-type granites in the region; the isotopic ratios are probably related to the metasomatism of the lithospheric mantle by sediment-derived melts. We suggest that the parental melts of the mafic-ultramafic intrusions and those of the high-K calc-alkaline granites were genetically related, and melts of the high-K calc-alkaline granites were probably derived from the melting of newly underplated calc-alkaline basic material at lower crustal depths, that were compositionally comparable to the parental magmas of the mafic-ultramafic intrusions.
