Figure 5 - uploaded by R. Damian Nance
Content may be subject to copyright.
800-490 Ma reconstructions of Laurentia-Gondwana-Baltica, emphasizing the history of the peri-Gondwanan terranes. This reconstruction satisfies the paleomagnetic database but Laurentia and Gondwana are permitted to migrate so as to make them compatible with the tectonothermal history of peri-Gondwanan terranes. This reconstruction also incorporates the low latitude option for Laurentia between at about 570 Ma. Click on image to view animation.
Source publication
Current debate regarding the configuration and breakup history of the late Precambrian supercontinent Rodinia has focused on the development of Grenville-aged orogenic belts and the evolution of Neoproterozoic passive margin sequences. However, supercontinent amalgamation and breakup also have profound tectonic effects on the evolution of continent...
Similar publications
Considerable debate surrounds the Late Neoproterozoic paleogeographic position of the Avalon terrane, specifically whether it was adjacent to West Africa or Amazonia. New paleomagnetic results from upper Neoproterozoic rocks in the Avalon terrane challenge the latter position. Samples col- lected from the ca. 580-570 Ma Marystown Group in the south...
Citations
... These correlations were focused on the relationships between America, North Africa (Morocco) and Europe. They were mainly conducted by J.B. Murphy and R.D. Nance (Murphy et al. 2001(Murphy et al. , 2011(Murphy et al. , 2018Nance 2002, 2005;Dennis et al. 2020;Kuiper et al. 2022). A central point of these correlations is related to the evolution of the Rheic Ocean (Murphy et al. 2006(Murphy et al. , 2009(Murphy et al. , 2010Nance and Linnemann 2008;Nance et al. 2010Nance et al. , 2012. ...
The Variscan orogen formed during closure of the Rheic Ocean and the final collision between the North American and West African cratons in the Late Paleozoic. This collision led to the multistage building of the Mauritanide belt to the east of the Variscan suture and to the building of the well-known Appalachian belt to the west. Both led to opposite vergences in this part of the Variscan belt. The earliest records of the main collision episode begin at ~360 Ma and end about 250 Ma ago, while a late extensional phase lasted until ~190 Ma.
... These correlations were focused on the relationships between America, North Africa (Morocco) and Europe. They were mainly conducted by J.B. Murphy and R.D. Nance (Murphy et al. 2001(Murphy et al. , 2011(Murphy et al. , 2018Nance 2002, 2005;Dennis et al. 2020;Kuiper et al. 2022). A central point of these correlations is related to the evolution of the Rheic Ocean (Murphy et al. 2006(Murphy et al. , 2009(Murphy et al. , 2010Nance and Linnemann 2008;Nance et al. 2010Nance et al. , 2012. ...
The Variscan orogen formed during closure of the Rheic Ocean and the final collision between the North American and West African cratons in the Late Paleozoic. This collision led to the multistage building of the Mauritanide belt to the east of the Variscan suture and to the building of the well-known Appalachian belt to the west. Both led to opposite vergences in this part of the Variscan belt. The earliest records of the main collision episode begin at ~360 Ma and end about 250 Ma ago, while a late extensional phase lasted until ~190 Ma.
... The breakup and dispersal of this vast marginal belt (Text- fig. 1a, b) resulted in the northward drift of several generations of peri-Gondwanan terranes (e.g., Murphy et al. 2001Murphy et al. , 2006Murphy and Nance 2004;Nance and Linemann 2008;Nance et al. 2010;Franke et al. 2017;von Raumer et al. 2017;Spahić et al. 2019a, b). A complex group of microcontinents comprised of East Avalonian and Armorican domains with dominantly Cadomian tectonic elements drifted away and became basements for the terrane agglomeration that formed the European Variscan Belt from Iberia to the Balkans (e.g., Aleksić et al. 1988;Neubauer 2002;Franz and Romer 2006;Himmerkus et al. 2009;Oczlon et al. 2010;Zagorchev et al. 2012;Balintoni et al. 2010aBalintoni et al. , b, 2014von Raumer et al. 2013;Keppie and Keppie 2014;Zurbriggen 2015;Antić et al. 2016;Abbo et al. 2019;Šoster et al. 2020;Text-figs 1c, 2). ...
In the Balkans, the Serbo-Macedonian Unit (SMU), Serbia, is thrust bounded by the composite Tethyan Vardar Zone and the Carpatho-Balkanides. The SMU actually emerges from beneath the Neoalpine Miocene–Pliocene deposits. Both provenance and geodynamic position of the SMU are poorly known and still debated. This paper reviews the data hitherto published and includes some new field data interpretations. The SMU is composed of a Neoproterozoic–Cambrian high-grade (para- and ortho-) gneiss with peraluminous magmatic arc components (560–470 Ma). The SMU is in the contact with Neoproterozoic upper Ordovician–Carboniferous low-grade metasedimentary succession of an accretionary wedge assembly represented by the Supragetic basement. The SMU basement became folded, sheared and metamorphosed around 490–450 Ma. Paleomagnetic data point to high southern latitudes and a peri-Gondwanan position of the SMU at that time, which concurs with glaciomarine evidence recorded from the upper Ordovician sediments at the base of an accretionary wedge succession. Based on the published data and field survey in the Stalać region, we correlate the SMU with the pre-Mesozoic gneiss terrane exposed in the Strona-Ceneri zone of the Alps. This terrane, identified as the Cenerian orogen of the Alaskan subduction type, developed at an active margin of Gondwana during middle Ordovician times. The SMU basement, with augen and migmatitic gneisses and arc-related peraluminous magmatic bodies, developed at this margin as part of the Cenerian belt or its equivalent. Such an orogenic edifice proved transient and in the earliest Silurian the SMU fragments drifted away being bound for Baltica (amalgamated Moesian microplate and Danubian terrane) to which they became accreted in the Carboniferous and included in the southern European branch of the Variscan orogen (Marginal Dacides/Carpatho-Balkanides). Despite considerable Variscan and Alpine reworking, the pre-Variscan, Cenerian-type crustal assembly along with an inferred boundary between the magmatic arc and the accretionary wedge, accompanied by back-arc/forearc deposits, are still decipherable in the Western Balkan countries.
... These zircons are characteristic for Avalonian rocks and witness the former Amazonian (AM in Fig. 1) connection of the Avalonian terranes (Nance and Murphy, 1996;Murphy et al., 2001). Zircons of that age (1.1-1.6 Ga) are typically missing in Armorican parts of the Variscides (Stephan et al., 2019), and they are also missing in the Moldanubian Ostrong and Gföhl units of the eastern Bohemian Massif (Finger et al., 2007b;Friedl et al., 2004;Košler et al., 2014). ...
Garnets in metapelitic paragneisses from the southern Drosendorf unit in the Austrian part of the Bohemian Massif exhibit two episodes of growth during the Variscan orogeny, which can be distinguished on textural and chemical grounds. The first garnet (grt1) records evidence of high-grade metamorphism in the Late Devonian (Frasnian–Famennian), while the second garnet (grt2) formed by a second high-grade event in the Early Carboniferous (Visean). Both garnet generations contain abundant inclusions, of which monazite, rutile and crystallised melt droplets are particularly useful for reconstructing P–T–t conditions. The Late Devonian age (373 ± 9 Ma) for the first episode of garnet growth was obtained from chemical dating of monazite inclusions in grt1. Metamorphic conditions during the first episode of garnet growth are estimated to have been between 0.7 and 0.8 GPa at 680–700 °C and 0.95–1.10 GPa at 745–785 °C. There followed a phase of cooling and exhumation, after which the second garnet (grt2) were formed beginning under amphibolite facies conditions and continuing prograde to peak conditions of 0.95–1.10 GPa and 745–785 °C, which are similar to those of the first garnet forming event. Subsequently, the rocks experienced near isothermal decompression to 0.5–0.8 GPa. Chemical dating of both monazite inclusions in grt2 and the matrix provide a Visean age (343 ± 3 Ma).
A study of detrital zircons in these paragneisses revealed zircon forming events at around 1.2, 1.5 and 1.8 Ga, suggesting an Avalonian provenance. The lack of zircons younger than 1 Ga and the presence of Cadomian metamorphic monazite relics (652 ± 15 Ma) indicates an Early Neoproterozoic deposition age for the sedimentary protolith likely. Our documentation of a Late Devonian high-grade metamorphic event in rocks derived from Avalonian corroborates tectonic models which assume that frontal parts of the Armorican terrane had already docked with Avalonia by this time.
... During Late Cambrian time, a series of super-large backarc basins developed along the northern margin of Gondwana (von Raumer and Stampfli, 2008;Nance et al., 2010Nance et al., , 2012Torsvik and Cocks, 2017), probably due to the subduction of the mid-oceanic ridge of the Iapetus Ocean (Murphy et al., 2006). During Early Ordovician time, these extensional basins had evolved a rift , which itself evolved into a mid-oceanic ridge, leading to the opening of the Rheic Ocean that tore up a strip of small continental fragments represented by the Avalonia, Armorica and Carolina arc terranes from the northern margin of Gondwana Nance, 1989, 2008 , 1997;Murphy et al., 2001;Cocks and Torsvik, 2002, 2007Bozkurt et al., 2008;Nance et al., 2002Nance et al., , 2010Nance et al., , 2012Nance and Linnemann, 2008;von Raumer and Stampfli, 2008;Pollock et al., 2009. Torsvik andCocks, 2017). ...
Pangea is the youngest supercontinent in Earth's history and its main body formed by assembly of Gondwana and Laurasia about 300–250 Ma ago. As supported by voluminous evidence from reliable geological, paleomagnetic and paleontological data, configurations of major continental blocks in Pangea have been widely accepted. However, controversy has long surrounded the reconstructions of East Asian blocks in Pangea. To determine whether or not the East Asian blocks were assembled to join Pangea before its breakup, we carried out geological and paleomagnetic investigations on East Asian blocks and associated orogenic belts, supported by a NSFC Major Program entitle “Reconstructions of East Asian blocks in Pangea”. Our results indicate that the breakup of Rodinia around 750 Ma ago led to the opening of the Proto-Tethys and Paleo-Asian oceans in East Asia, with the former separating the South China, North China, Alex Qaidam and Tarim blocks from other East Asian blocks at the margins of Australia and India, whereas the Paleo-Asian Ocean existed between the East Asian blocks and Siberia-Eastern Europe. The Proto-Tethys Ocean closed in the early Paleozoic (500–420 Ma), leading to the collision of South China, North China, Alex, Qaidam and Tarim with other East Asian blocks at the northern margin of Gondwana. The subduction of the Paleo-Asian Ocean formed the Central Asian Orogenic Belt, the largest accretionary orogen in Earth's history, and its closure was diachronous, with its western, central and eastern segments closing at 310–280 Ma, 280–265 Ma and 260–245 Ma, respectively, leading the Tarim, Alex and North China blocks to join Eastern Europe-Siberia as part of Pangea. During the early Devonian (420–380 ma), the East Paleo-Tethys Ocean opened with two branches, of which the north branch is called the Mianlue Ocean that separated the Tarim-Qaidam-Central Qilian-Alex and North China blocks in the north from North Qiangtang-Indochina-South China in the south, and the south branch is the stricto sensu East Paleo-Tethys Ocean that separated North Qiangtang-Indochina-South China from the Sibumasu and South Qiangtang-Lhasa blocks at the northern margin of Gondwana. In the Triassic, the East Paleo-Tethys Ocean (stricto sensu) closed along the Longmu Co – Shuanghu – Changning – Menglian – Inthanon belt, leading to the collision of North Qiangtang-Indochina-South China with Sibumasu and South Qiangtang-Lhasa, forming a single southern continent, which then collided with the Tarim-Qaidam-Central Qilian-Alex and North China blocks to form a coherent East Asian continent that had become part of Pangea by 220 Ma, when the Mianlue Ocean closed, leading to the formation of the E-W-trending Central China Orogenic System.
... In the Late Ediacaran and Early Paleozoic, several crustal blocks of central Europe were located at the Northern margin of Gondwana, being part of the Avalonian-Cadomian active margin (van der Voo et al. 1984;van der Voo 1988;Nance and Thompson 1996;Stampfli 2000;Murphy et al. 2001;Stampfli et al. 2002Stampfli et al. , 2011Stampfli et al. , 2013von Raumer et al. 2003von Raumer et al. , 2015Linnemann et al. 2004Linnemann et al. , 2007. Hence, these peri-Gondwanan domains show a typical Northern African fingerprint, which is particularly well-recorded by detrital zircons in the Saxothuringian and Moldanubian units (Linnemann et al. 2004(Linnemann et al. , 2007Ábalos et al. 2012;Avigad et al. 2012;Williams et al. 2012;Fernández-Suárez et al. 2014;Shaw et al. 2014;Dörr et al. 2015Dörr et al. , 2017Gutiérrez-Alonso et al. 2015). ...
New U–Pb and Lu–Hf detrital zircon data together with whole-rock geochemical and Sm–Nd data were obtained for parag- neisses of the Austroalpine basement south of the Tauern Window. Geochemically immature metasediments of the North- ern–Defereggen–Petzeck (Ötztal–Bundschuh nappe system) and Defereggen (Drauzug–Gurktal nappe system) groups contain zircon age populations which indicate derivation mainly from Pan-African orogens. Younger, generally mature metasediments of the Gailtal Metamorphic Basement (Drauzug–Gurktal nappe system), Thurntaler Phyllite Group (Drauzug–Gurktal nappe system) and Val Visdende Formation (South Alpine Basement) were possibly derived from more distant sources. Their sig- ni cantly larger abundances of pre-Pan-African zircons record a more advanced stage of downwearing of the Pan-African belts and erosion of older basement when the Austroalpine terrane was part of the Early Palaeozoic Northern Gondwana passive margin. Most zircon age spectra are dominated by Ediacaran sources, with lesser Cryogenian, Tonian and Stenian contributions and subordinate Paleoproterozoic and Neoarchean ages. These age patterns are similar to those recorded by Cambro–Ordovician sedimentary sequences in northeastern Africa between Libya and Jordan, and in some pre-Variscan basement inliers of Europe (e.g. Dinarides–Hellenides, Alboran microplate). Therefore, the most likely sources seem to be in the northeastern Saharan Metacraton and the Northern Arabian–Nubian Shield (Sinai), further supported by whole-rock Sm–Nd and zircon Lu–Hf data.
... The presented evidences from zircon Hf isotopes characteristics of the crustal contribution, in addition to the Late Ediacaran-Early Cambrian emplacement ages of the DMIC ($545 Ma), totally indicate the DMIC rocks generated related to the widespread crustal melting and post-tectonic activities at $550-540 Ma. These activities were reported by many authors (e. g. Murphy et al., 2001;Linnemann et al., 2008;Nance et al., 2010;Fiannacca et al., 2013) at the Northern margin of Gondwana at the end of the Neoproterozoic. ...
The Delbar Metamorphic-Igneous Complex (DMIC) consists of the medium to high-grade metamorphic rocks and granites – leucogranites is located in the Biarjmand region, in Central Iran. U–Pb dating of the gneisses yielded the ages of 546 ± 3.7–547 ± 6.8 Ma similar to the crystallization ages of leucogranites (541 ± 4.7–547 ± 11 Ma) are consistent to the Late Ediacaran–Early Cambrian ages of Cadomian magmatic arc (∼545 Ma). The 206Pb/238U ages of the detrital zircons from the mica-schists sample are from 551 ± 5.1–549 ± 5.1 Ma. The youngest ages of the meta-pelitic protolith have 10 Ma age intervals compared to the granites emplacement age, which indicates rapid Late Precambrian crustal recycling involving erosion, burial, metamorphism to partial melting of the continental crust in less than ca. 10 Ma. These rapid crustal evolutions were related to the final collision and amalgamation of Gondwana, the Rheic Ocean clouser and coeval paleotethys opening at the end of the Avalonian–Cadomian orogeny. The studied granites are similar to the volcanic arc granitoids and originated from the crustal source in an active continental margin based on the geochemical characteristics and Hf isotopes data. Exhumation of the DMIC Complex, is marked by deposition of Lower Jurassic conglomerates contains pebbles of basement rocks. These rocks were interrupted by mafic swarms dikes that have generated in a back arc extensional setting related to the Neotethys subduction under the Central Iran at the 152 ± 35 Ma (Middle–Late Jurassic) based on the U–Pb apatite dating.
... The late Ediacaran to early Cambrian emplacement ages of the granitoid protoliths of the inheritance-rich augen gneisses (ca. 545Ma), together with their typical high-K calc-alkaline post-collisional geochemical features and strong evidence from zircon inheritance and Sr-Nd isotopes for crustal contributions to the magmas, are consistent with the widespread crustal melting and post-tectonic granitoid emplacement at ca. 550-540Ma reported by many authors (e.g., Murphy et al., 2001 and references therein; Linnemann et al., 2008;Nance et al., 2010) as having marked the transition from subduction to strike-slip tectonics at the northern margin of Gondwana at the end of the Neoproterozoic. There is indeed general agreement that an active Andean-type continental margin, featuring magmatic arcs and back-arc basins, formed the entire northern margin of Gondwana, with subduction beginning at about 760 Ma and ending diachronously with the development of transform fault systems (e.g. ...
The medium- to high-grade polymetamorphic basement rocks of the Peloritani Mountains, northern Sicily, include large volumes of augen gneiss of controversial age and origin. By means of a geochemical and SHRIMP zircon study of representative samples, the emplacement age of the original granitoid protoliths of the augen gneisses and the most likely processes and sources involved in that granitoid magmatism have
been determined. U–Pb dating of three samples from widely spaced localities in the Peloritani Mountains yielded igneous protolith ages of 565±5, 545±4 and 545±4Ma, respectively. These late Ediacaran/early Cambrian ages are much older than was previously assumed on geological grounds, and are typical of the
peri-Gondwanan terranes involved in the geodynamic evolution of the northern Gondwana margin at the end of the Avalonian–Cadomian orogeny. Major and trace element compositions and Sr–Nd isotopic data, in combination with zircon inheritance age patterns, suggest that the granitoid protoliths of the Sicilian and coeval Calabrian augen gneisses were generated by different degrees of mixing between sediment and
mantle-derived magmas. The magmas forming the ca. 545Ma inheritance-rich granitoids appear to have had a signi!cant contribution from partial melting of paragneiss that is the dominant rock type in the medium- to high-grade Peloritanian basement. The closeness of the inferred deposition age of the greywacke protoliths of the paragneisses with the intrusion age of the granitoids indicates rapid latest Precambrian crustal recycling involving erosion, burial, metamorphism to partial melting conditions, and extensive granitoid magmatism in less than ca. 10Ma.
... The continental arc of the Hun Superterrane split successively into terranes separated from Gondwana and drifted off northwards pushed by the extending Palaeotethys Ocean (see Fig. 11). The distribution of crystallisation ages in the Vertiskos Terrane indicates that it belongs to the Cadomian terranes (Murphy et al., 2001;Linnemann et al., 2004;Himmerkus et al., 2007). ...
New geochronological and geochemical data on basement orthogneisses from the Vertiskos Unit of the Serbo-Macedonian Massif (SMM), Internal Hellenides, northern Greece, are used in order to constrain the pre-Alpine tectonic history of the basement units in the metamorphic hinterland of the Hellenides.The prevailing rock types in the Vertiskos crystalline basement are coarse-grained biotite augengneisses with subordinate leucocratic muscovite gneisses and two-mica gneisses. Zircon Pb–Pb and U–Pb ages on 20 samples range from 425.9 ± 4.2 Ma to 443.4 ± 5.5 Ma with a mean of 432.2 ± 3.2 Ma and are interpreted as primary crystallisation ages of the basement granites on the basis of the magmatic internal structure of the zircon grains. Trace-element and isotope geochemistry of the gneisses show that they originated in a magmatic-arc setting, but also contain material from pre-existing continental crust. The rocks are slightly peraluminous and some leucocratic gneisses are strongly depleted in incompatible trace elements.The zircon ages document an early Silurian magmatic phase in the Internal Hellenides. The association of lithologies and ages is distinctly different from that of the adjacent basement massifs. This difference in basement provenance and the fact that the Vertiskos Unit is bordered by ophiolitic material both to the west and to the east leads to the conclusion that this part of the SMM is an exotic terrane of northern Gondwanan origin, which was finally accreted to its present position during the Alpine orogeny. The Vertiskos Terrane may have been part of the Hun Superterrane, which evolved at the northern active continental margin of Gondwana in the early Palaeozoic and rifted away from it during the opening of the Rheic Ocean in the Cambrian to Silurian. Parts of this superterrane such as the Vertiskos Terrane are present throughout the Variscan and Alpine orogens.
... The distinct 546Á0 AE 8Á6 Ma inherited component corresponds in age to widespread granitic magmatism and metamorphism in many terranes of southern Europe that was related to the late collisional stages of the Pan-African orogeny at the northern Gondwanan margin, or to the transition to a passive continental margin (Villeneuve & Corne¤ e, 1994;Zulauf et al., 1999;Murphy et al., 2001;Linnemann et al., 2004;Zeck et al., 2004;Gasquet et al., 2005;Micheletti et al., 2007). ...
Sensitive high-resolution ion microprobe (SHRIMP) analyses of
zircon from granites of the medium-high grade Aspromonte^
Peloritani Unit, Calabria^Peloritani Orogen (CPO), southern
Italy, show that one of the minor trondhjemites (313�7�3�5Ma)
represents the earliest identified occurrence of Late Hercynian peraluminous
igneous rocks in the CPO, predating the emplacement of
the more common peraluminous leucogranodiorites by about 14 Myr.
Some of the trondhjemite zircon grains contain small cores with ages
of about 2�45 Ga, 625Ma and 490Ma, consistent with the presence
of a sediment component in the magma. A newly dated leucogranodiorite
(300�2�3�8Ma) is rich in inherited zircon. Cores with
ages of about 2�36 Ga, 870Ma, 630Ma, 545Ma and 460Ma are
overgrown by two generations of Hercynian igneous zircon, the first
with moderate to highTh/U (up to 1� 67), and the second with low
Th/U (50�1).The overgrowths probably crystallized from magmas
of two compositions, the first metaluminous and the second peraluminous.
This could indicate either magma mixing or, more probably,
crystallization in a single, evolving magma. In either case, the leucogranodiorite
magma is considered to have been the product of anatexis
of a metasedimentary source. Differences in the inherited
zircon age spectra, and the relatively small amount of inheritance in
the trondhjemite, indicate that the trondhjemite and leucogranodiorite
are unlikely to be genetically related.The ages of the inherited zircons
are consistent with the sedimentary component in both magmas being
derived from North Africa, with a possible contribution from
Pan-African granitoids similar to those exposed in southern
Calabria.
