We document,for the first time,Mesoproterozoic-aged,continental arc magmatism in the Tasmanides.Granitoid samples intruding the Proterozoic Cape River Metamorphics in northeast Queensland contain abundant∼1200 Ma ign...We document,for the first time,Mesoproterozoic-aged,continental arc magmatism in the Tasmanides.Granitoid samples intruding the Proterozoic Cape River Metamorphics in northeast Queensland contain abundant∼1200 Ma igneous zircons,with early-Paleozoic metamorphic rim overgrowths.Analytical mixing between the igneous and metamorphic zircons produces cryptic discordant analyses,but the origin of said discordance is resolved with zircon Th/U ratios.Samples of the Fat Hen Creek Complex are peraluminous,calc-alkaline,S-type granitoids,that record high-grade metamorphism and trace element mobilization.The P3 and P42 intrusions are metaluminous,calc-alkaline,I-type granodiorite,which intruded the Cape River Metamorphics,and contain trace element signatures consistent with a continental-arc setting.We propose that a Mesoproterozoic continental terrane,herein referred to as the Oakvale Province,exists as basement to the Thomson Orogen.We propose several models for the formation of the Oakvale Province,with potential links to the Tarim Block,and the Yangtze Craton,during the late-Mesoproterozoic.We propose that the Oakvale Province supplied the Tasmanides with late-Mesoproterozoic detritus,and that such detritus was not solely sourced from the Musgrave Province as previously interpreted.Finally,we interpret the oroclinal bending of Paleozoic deformation and plutonic fabrics to reflect the buried extent of the Oakvale Province,and to potentially map out the Neoproterozoic rift margin associated with Rodinia break-up.展开更多
Columbia(Nuna)is a Paleo-Mesoproterozoic supercontinent that was assembled during global 2.0–1.8Ga collisional events,underwent long-lived,subductionrelated accretion at key continental margins in the period
The Alto MoxotóTerrane of the Borborema Province presents a wide exposure of Paleoproterozoic crust,but unlike other continental blocks of South America,its orogenic history is strongly obliterated by late Neopro...The Alto MoxotóTerrane of the Borborema Province presents a wide exposure of Paleoproterozoic crust,but unlike other continental blocks of South America,its orogenic history is strongly obliterated by late Neoproterozoic deformation.New isotopic and geochemical studies were conducted in mafic-ultramafic(Fazenda Carmo Suite)and granitic-gneissic rocks(Riacho do Navio Suite)within the terrane.The former present zircon U-Pb crystallization ages at ca.2.13 Ga,whereas Sm-Nd data suggests a juvenile origin via melting of early Paleoproterozoic to Archean peridotitic sources.Geochemical data for these rocks are compatible with tholeiitic magmas with some degree of crustal contamination and trace element distribution points to a continental-arc related setting interpreted as remnants of the early stages of subduction.In contrast,the Riacho do Navio Suite was emplaced at ca.2.08 Ga and has highly negativeεNd(t)values indicating crustal reworking.The suite displays calc-alkali to alkali-calcic and ferroan geochemical signatures compatible with Cordilleran magmas.In addition,trace-element distribution as well as discriminant diagrams suggest that the precursor magmas were generated during the later stages of a continental arc or in a syn-collisional setting.Based on our results,we suggest that the studied units might represent missing pieces of a Paleoproterozoic accretionary orogen that formed the crustal framework of the Alto MoxotóTerrane,and that this represents a block associated with assembly of the Nuna/Columbia supercontinent,which is now largely hidden within the Neoproterozoic orogenic belts of West Gondwana.展开更多
The number of good quality paleomagnetic data of the Mesoproterozoic supercontinent Nuna(e.g.Columbia,Hudsonland)has increased in recent years enabling more reliable global continental reconstructions(e.g Hoffman
Supported on available paleomagnetic data,a new Columbia(Nuna)supercontinent reconstruction is proposed based on matching U-Pb-dated 1.79-1.75 Ga Large Igneous Province(LIP)mafic unit fragments and particularly on lin...Supported on available paleomagnetic data,a new Columbia(Nuna)supercontinent reconstruction is proposed based on matching U-Pb-dated 1.79-1.75 Ga Large Igneous Province(LIP)mafic unit fragments and particularly on linking their dykes into radiating systems.Information from the literature is augmented with the herein dated 1762 Ma(U-Pb)Januária dyke swarm from the São Francisco Craton(Brazil).展开更多
The Paleoproterozoic basement of the northeastern part of the Leo-Man craton is intruded by generally NW-trending dikes. These regional scale dikes extend over 1000 km in Burkina Faso, Mali and Niger. We present chemi...The Paleoproterozoic basement of the northeastern part of the Leo-Man craton is intruded by generally NW-trending dikes. These regional scale dikes extend over 1000 km in Burkina Faso, Mali and Niger. We present chemical and Sr-Nd isotope compositions, as well as 40 Ar/39 Ar ages of these dikes with the following strikes N98°-N112°, and N114°-N124° in NE Burkina Faso. Field relationships show that the dikes are posterior to all other rock types dated between 2.26 Ga and 2.0 Ga. Chemical data indicate that the dikes are continental flood basalts and composed of low-Ti(TiO2 ≤ 2 wt.%) sub-alkaline basalts and andesites. They exhibit a minor negative Europium anomaly(0.86-0.99) and slightly fractionated REE patterns((La/Yb)_N= 2.5-9.1; Yb_N = 9.5-19.9). The ratios of Th/Ta(1.3-11.4) and Ce/Pb(5.2-58.5)suggest a varying crustal assimilation of the dike magmas during ascent in the continental crust for all studied samples. Calculated P-T conditions indicate that the magma reached temperatures of 1285 ℃(calculated from olivine compositions) and pressures of 6.9 kbar(calculated for pyroxene minerals).Calculated initial 87 Sr/86 Sr(0.70040-0.70260) and ε_(Nd)(t)=+2.1 to-3.5 at 1575 Ma,also point to a crustal contamination with the most primitive samples showing T_(DM) values of 1946 Ma and 2154 Ma. The low values of La/Ba(<0.2) and Nb/La(<1.0), contrast with the low Th/Nb(<0.9), and suggest a lithospheric mantle or subduction-modified mantle as possible source for the dikes. Sr-Nd data, Mg# and NbTa-Zr-Y-Th-Tb-Yb compositions further suggest that the most primitive samples were emplaced in a none orogenic setting and their magmas were subjected to variable crustal contaminations. Literature and the present whole rock 40 Ar/39 Ar age determinations show that the dikes were emplaced during a widespread Mesoproterozoic magmatism between 1.6 Ga and 1.2 Ga, and were affected by a thermal event causing the argon systematics resetting, best constrained by the date of sample KK1(1236 ± 20 Ma,^(40)Ar/^(36)Ar = 294 ±13, MSWD = 2.2). Contemporaneous 1590-1570 Ma extensive magmatism is reported in other crustal blocks in Baltica(Sveconorw-Goth, svecofennian) NW Laurentia(Slave craton, Yukon),and Australia(Gawler craton), and together with the 1575 studied dikes, are related to the breakup of the supercontinent Nuna.展开更多
Comparisons of large igneous provinces(UPs)and black shales from different cratons can provide important constraints on Precambrian paleogeographic reconstructions and a better understanding of the environmental effec...Comparisons of large igneous provinces(UPs)and black shales from different cratons can provide important constraints on Precambrian paleogeographic reconstructions and a better understanding of the environmental effects of large-scale volcanic events.A comparison of intraplate mafic events mostly interpreted as LIPs or portions of LIPs(LIP fragments/remnants due to continental breakup or erosion)from the North China Craton(NCC)and North Australian Craton(NAC)shows good correlation in the age range from 1800 Ma to 1300 Ma,and four robust age matches at ca.1790-1770 Ma,ca.1730 Ma,ca.1680-1670 Ma and ca.1320 Ma have been identified.Most notably,the coeval ca.1320 Ma Yanliao LIP in the eastern-northern NCC and the Derim Derim-Galiwinku LIP in the NAC are also characterized by similar field occurences and dominantly subalkaline tholeiitic basalts and intraplate geochemical compositions,and are interpreted as portions of the same LIP,separated by continental breakup.Subsequent to 1300 Ma,the NCC and NAC exhibit very different magmatic histories,indicating that separation of these two cratons occurred,likely subsequent to the ca.1320 Ma LIP event.A comparison of Paleo-Mesoproterozoic black shales from the NCC and NAC provides further evidence for close connections between these regions during this period.Black shales of the Chuanlianggou Formation in the northern NCC and the Cuizhuang Formation in the southern NCC were deposited in the age range ca.1650-1635 Ma and can be correlated with ca.1640-1635 Ma black shales in the Barney Creek Formation of the NAC.Deposition of black shales within the Xiamaling Formation in the NCC and the Velkerri and Kyalla formations of the McArthur Basin in the NAC occurred synchronously at ca.1380-1360 Ma.Our results from matching of LIP ages and black shales combined with paleomagnetic data show that the northern-northeastern margin of the NCC was connected to the northern margin of the NAC from ca.1800 Ma to 1300 Ma.This long-lived late Paleoproterozoic to mid-Mesoproterozoic connection lasted for at least 500 million years until separation of the NCC from the NAC between ca.1320 and ca.1230-1220 Ma.展开更多
Understanding the intricate relationships between the solid Earth and its surface systems in deep time necessitates comprehensive full-plate tectonic reconstructions that include evolving plate boundaries and oceanic ...Understanding the intricate relationships between the solid Earth and its surface systems in deep time necessitates comprehensive full-plate tectonic reconstructions that include evolving plate boundaries and oceanic plates.In particular,a tectonic reconstruction that spans multiple supercontinent cycles is important to understand the long-term evolution of Earth’s interior,surface environments and mineral resources.Here,we present a new full-plate tectonic reconstruction from 1.8 Ga to present that combines and refines three published models:one full-plate tectonic model spanning 1 Ga to present and two continental-drift models focused on the late Paleoproterozoic to Mesoproterozoic eras.Our model is constrained by geological and geophysical data,and presented as a relative plate motion model in a paleomagnetic reference frame.The model encompasses three supercontinents,Nuna(Columbia),Rodinia,and Gondwana/Pangea,and more than two complete supercontinent cycles,covering40%of the Earth’s history.Our refinements to the base models are focused on times before 1.0 Ga,with minor changes for the Neoproterozoic.For times between 1.8 Ga and 1.0 Ga,the root mean square speeds for all plates generally range between 4 cm/yr and 7 cm/yr(despite short-term fast motion around 1.1 Ga),which are kinematically consistent with post-Pangean plate tectonic constraints.The time span of the existence of Nuna is updated to between 1.6 Ga(1.65 Ga in the base model)and 1.46 Ga based on geological and paleomagnetic data.We follow the base models to leave Amazonia/West Africa separate from Nuna(as well as Western Australia,which only collides with the remnants of Nuna after initial break-up),and South China/India separate from Rodinia.Contrary to the concept of a“boring billion”,our model reveals a dynamic geological history between 1.8 Ga and 0.8 Ga,characterized by supercontinent assembly and breakup,and continuous accretion events.The model is publicly accessible,providing a framework for future refinements and facilitating deep time studies of Earth’s system.We suggest that the model can serve as a valuable working hypothesis,laying the groundwork for future hypothesis testing.展开更多
文摘We document,for the first time,Mesoproterozoic-aged,continental arc magmatism in the Tasmanides.Granitoid samples intruding the Proterozoic Cape River Metamorphics in northeast Queensland contain abundant∼1200 Ma igneous zircons,with early-Paleozoic metamorphic rim overgrowths.Analytical mixing between the igneous and metamorphic zircons produces cryptic discordant analyses,but the origin of said discordance is resolved with zircon Th/U ratios.Samples of the Fat Hen Creek Complex are peraluminous,calc-alkaline,S-type granitoids,that record high-grade metamorphism and trace element mobilization.The P3 and P42 intrusions are metaluminous,calc-alkaline,I-type granodiorite,which intruded the Cape River Metamorphics,and contain trace element signatures consistent with a continental-arc setting.We propose that a Mesoproterozoic continental terrane,herein referred to as the Oakvale Province,exists as basement to the Thomson Orogen.We propose several models for the formation of the Oakvale Province,with potential links to the Tarim Block,and the Yangtze Craton,during the late-Mesoproterozoic.We propose that the Oakvale Province supplied the Tasmanides with late-Mesoproterozoic detritus,and that such detritus was not solely sourced from the Musgrave Province as previously interpreted.Finally,we interpret the oroclinal bending of Paleozoic deformation and plutonic fabrics to reflect the buried extent of the Oakvale Province,and to potentially map out the Neoproterozoic rift margin associated with Rodinia break-up.
文摘Columbia(Nuna)is a Paleo-Mesoproterozoic supercontinent that was assembled during global 2.0–1.8Ga collisional events,underwent long-lived,subductionrelated accretion at key continental margins in the period
基金support from Australian Research Council grant FL160100168supported by the National Institute of Science and Technology for Tectonic Studies(INCT)of Brazil。
文摘The Alto MoxotóTerrane of the Borborema Province presents a wide exposure of Paleoproterozoic crust,but unlike other continental blocks of South America,its orogenic history is strongly obliterated by late Neoproterozoic deformation.New isotopic and geochemical studies were conducted in mafic-ultramafic(Fazenda Carmo Suite)and granitic-gneissic rocks(Riacho do Navio Suite)within the terrane.The former present zircon U-Pb crystallization ages at ca.2.13 Ga,whereas Sm-Nd data suggests a juvenile origin via melting of early Paleoproterozoic to Archean peridotitic sources.Geochemical data for these rocks are compatible with tholeiitic magmas with some degree of crustal contamination and trace element distribution points to a continental-arc related setting interpreted as remnants of the early stages of subduction.In contrast,the Riacho do Navio Suite was emplaced at ca.2.08 Ga and has highly negativeεNd(t)values indicating crustal reworking.The suite displays calc-alkali to alkali-calcic and ferroan geochemical signatures compatible with Cordilleran magmas.In addition,trace-element distribution as well as discriminant diagrams suggest that the precursor magmas were generated during the later stages of a continental arc or in a syn-collisional setting.Based on our results,we suggest that the studied units might represent missing pieces of a Paleoproterozoic accretionary orogen that formed the crustal framework of the Alto MoxotóTerrane,and that this represents a block associated with assembly of the Nuna/Columbia supercontinent,which is now largely hidden within the Neoproterozoic orogenic belts of West Gondwana.
文摘The number of good quality paleomagnetic data of the Mesoproterozoic supercontinent Nuna(e.g.Columbia,Hudsonland)has increased in recent years enabling more reliable global continental reconstructions(e.g Hoffman
基金support of the Brazilian National Council for Scientific and Technological Development(CNPq).
文摘Supported on available paleomagnetic data,a new Columbia(Nuna)supercontinent reconstruction is proposed based on matching U-Pb-dated 1.79-1.75 Ga Large Igneous Province(LIP)mafic unit fragments and particularly on linking their dykes into radiating systems.Information from the literature is augmented with the herein dated 1762 Ma(U-Pb)Januária dyke swarm from the São Francisco Craton(Brazil).
基金financially supported by research grant from the National Science Council(NSC 102-2811-M-002-200)the Ministry of Science and Technology grant(MOST 106-2116-M-002-017-MY3)
文摘The Paleoproterozoic basement of the northeastern part of the Leo-Man craton is intruded by generally NW-trending dikes. These regional scale dikes extend over 1000 km in Burkina Faso, Mali and Niger. We present chemical and Sr-Nd isotope compositions, as well as 40 Ar/39 Ar ages of these dikes with the following strikes N98°-N112°, and N114°-N124° in NE Burkina Faso. Field relationships show that the dikes are posterior to all other rock types dated between 2.26 Ga and 2.0 Ga. Chemical data indicate that the dikes are continental flood basalts and composed of low-Ti(TiO2 ≤ 2 wt.%) sub-alkaline basalts and andesites. They exhibit a minor negative Europium anomaly(0.86-0.99) and slightly fractionated REE patterns((La/Yb)_N= 2.5-9.1; Yb_N = 9.5-19.9). The ratios of Th/Ta(1.3-11.4) and Ce/Pb(5.2-58.5)suggest a varying crustal assimilation of the dike magmas during ascent in the continental crust for all studied samples. Calculated P-T conditions indicate that the magma reached temperatures of 1285 ℃(calculated from olivine compositions) and pressures of 6.9 kbar(calculated for pyroxene minerals).Calculated initial 87 Sr/86 Sr(0.70040-0.70260) and ε_(Nd)(t)=+2.1 to-3.5 at 1575 Ma,also point to a crustal contamination with the most primitive samples showing T_(DM) values of 1946 Ma and 2154 Ma. The low values of La/Ba(<0.2) and Nb/La(<1.0), contrast with the low Th/Nb(<0.9), and suggest a lithospheric mantle or subduction-modified mantle as possible source for the dikes. Sr-Nd data, Mg# and NbTa-Zr-Y-Th-Tb-Yb compositions further suggest that the most primitive samples were emplaced in a none orogenic setting and their magmas were subjected to variable crustal contaminations. Literature and the present whole rock 40 Ar/39 Ar age determinations show that the dikes were emplaced during a widespread Mesoproterozoic magmatism between 1.6 Ga and 1.2 Ga, and were affected by a thermal event causing the argon systematics resetting, best constrained by the date of sample KK1(1236 ± 20 Ma,^(40)Ar/^(36)Ar = 294 ±13, MSWD = 2.2). Contemporaneous 1590-1570 Ma extensive magmatism is reported in other crustal blocks in Baltica(Sveconorw-Goth, svecofennian) NW Laurentia(Slave craton, Yukon),and Australia(Gawler craton), and together with the 1575 studied dikes, are related to the breakup of the supercontinent Nuna.
基金the National Natural Science Foundation of China(Grants No.41725011,41920104004)the National Key Research and Development Project of China(Grant No.2020YFA0714803)+1 种基金REE was partially supported by Russian Mega-Grant(Grant No.14.Y26.31.0012)We are grateful to Darryl Stacey and Shannon Walsh(both NTGS)for help during drill core sample collecting in Darwin,Australia.The manuscript has benefited from thoughtful and constructive reviews by two anonymous reviewers,which significantly improved the quality of our paper.Tim Munson publishes with the permission of the Executive Director,Northern Territory Geological Survey.
文摘Comparisons of large igneous provinces(UPs)and black shales from different cratons can provide important constraints on Precambrian paleogeographic reconstructions and a better understanding of the environmental effects of large-scale volcanic events.A comparison of intraplate mafic events mostly interpreted as LIPs or portions of LIPs(LIP fragments/remnants due to continental breakup or erosion)from the North China Craton(NCC)and North Australian Craton(NAC)shows good correlation in the age range from 1800 Ma to 1300 Ma,and four robust age matches at ca.1790-1770 Ma,ca.1730 Ma,ca.1680-1670 Ma and ca.1320 Ma have been identified.Most notably,the coeval ca.1320 Ma Yanliao LIP in the eastern-northern NCC and the Derim Derim-Galiwinku LIP in the NAC are also characterized by similar field occurences and dominantly subalkaline tholeiitic basalts and intraplate geochemical compositions,and are interpreted as portions of the same LIP,separated by continental breakup.Subsequent to 1300 Ma,the NCC and NAC exhibit very different magmatic histories,indicating that separation of these two cratons occurred,likely subsequent to the ca.1320 Ma LIP event.A comparison of Paleo-Mesoproterozoic black shales from the NCC and NAC provides further evidence for close connections between these regions during this period.Black shales of the Chuanlianggou Formation in the northern NCC and the Cuizhuang Formation in the southern NCC were deposited in the age range ca.1650-1635 Ma and can be correlated with ca.1640-1635 Ma black shales in the Barney Creek Formation of the NAC.Deposition of black shales within the Xiamaling Formation in the NCC and the Velkerri and Kyalla formations of the McArthur Basin in the NAC occurred synchronously at ca.1380-1360 Ma.Our results from matching of LIP ages and black shales combined with paleomagnetic data show that the northern-northeastern margin of the NCC was connected to the northern margin of the NAC from ca.1800 Ma to 1300 Ma.This long-lived late Paleoproterozoic to mid-Mesoproterozoic connection lasted for at least 500 million years until separation of the NCC from the NAC between ca.1320 and ca.1230-1220 Ma.
基金Shandong Outstanding Youth Science Foundation(China)(2023HWYQ-065)Taishan Scholar Program(China)(tsqn202306114)+7 种基金National Key R&D Program of China(2022YFF0800401)ASC acknowledges funding through Australian Research Council projects LP210200822,LP200301457,FT120100340,FL240100114 and the MinEx CRCHis contribution forms MinEx publication#2024/37SL is funded by National Natural Science Foundation of China(Nos.42121005,91958214)Shandong Provincial Natural Science Foundation(China)(No.ZR2021YQ25)the Marine S&T Fund of Shandong Province for Laoshan Laboratory(No.2022QNLM050302)SP was supported by the Australian Research Council Laureate Fellowship grant to Z.X.Li(FL150100133)This study is a contribution to IGCP 648.NF acknowledges funding through Australian Research Council projects LP220100056 and FT230100001。
文摘Understanding the intricate relationships between the solid Earth and its surface systems in deep time necessitates comprehensive full-plate tectonic reconstructions that include evolving plate boundaries and oceanic plates.In particular,a tectonic reconstruction that spans multiple supercontinent cycles is important to understand the long-term evolution of Earth’s interior,surface environments and mineral resources.Here,we present a new full-plate tectonic reconstruction from 1.8 Ga to present that combines and refines three published models:one full-plate tectonic model spanning 1 Ga to present and two continental-drift models focused on the late Paleoproterozoic to Mesoproterozoic eras.Our model is constrained by geological and geophysical data,and presented as a relative plate motion model in a paleomagnetic reference frame.The model encompasses three supercontinents,Nuna(Columbia),Rodinia,and Gondwana/Pangea,and more than two complete supercontinent cycles,covering40%of the Earth’s history.Our refinements to the base models are focused on times before 1.0 Ga,with minor changes for the Neoproterozoic.For times between 1.8 Ga and 1.0 Ga,the root mean square speeds for all plates generally range between 4 cm/yr and 7 cm/yr(despite short-term fast motion around 1.1 Ga),which are kinematically consistent with post-Pangean plate tectonic constraints.The time span of the existence of Nuna is updated to between 1.6 Ga(1.65 Ga in the base model)and 1.46 Ga based on geological and paleomagnetic data.We follow the base models to leave Amazonia/West Africa separate from Nuna(as well as Western Australia,which only collides with the remnants of Nuna after initial break-up),and South China/India separate from Rodinia.Contrary to the concept of a“boring billion”,our model reveals a dynamic geological history between 1.8 Ga and 0.8 Ga,characterized by supercontinent assembly and breakup,and continuous accretion events.The model is publicly accessible,providing a framework for future refinements and facilitating deep time studies of Earth’s system.We suggest that the model can serve as a valuable working hypothesis,laying the groundwork for future hypothesis testing.
