Collision and amalgamation of continent and microcontinent block were recognized as one of the major processes for building up a continent. The pre Jurassic structure of Northeast China and its adjacent region (inclu...Collision and amalgamation of continent and microcontinent block were recognized as one of the major processes for building up a continent. The pre Jurassic structure of Northeast China and its adjacent region (including south of Russia Far East, north of North Korea and inner part of southwest Japan) is characterized by collision and amalgamation of microcontinent blocks, such as the North China block (NCB), Northeast China block (NECB), Khanka block and Hida block.The central Jilin belt and Yanbian Grodekovsk belt that juxtapose and amalgamate these blocks in between in Northeast China and its vicinity were formed by a series of rock assemblages that are typical for Paleozoic active continental margin island arcs. The dominant Permian marine sequences in Yanbian (Yanbian Grodekovsk) belt, which are known for bearing transitional marine fauna, include turbidite olistostrome sediments of a slope facies, and limestones, sandstones as well as siltstones of a neritic littoral facies sediments along with predominant acidic to intermediate volcanic materials. The Maizuru belt in southwest Japan is supposed to be the equivalent of Yanbian Grodekovsk belt. The central Jilin belt consists of a well developed sedimentary sequence and volcanics of Paleozoic. The Bamiantong Gudonghe Fuerhe Chongjin suture complex in Northeast China and the equivalent Sangun Akiyoshi belt in southwest Japan serve as a major suture zone among these microcontinental blocks and belts.展开更多
Black shales are important products of material cycling and energy exchange among the lithosphere,atmosphere,hydrosphere,and biosphere.They are widely distributed throughout geological history and provide essential en...Black shales are important products of material cycling and energy exchange among the lithosphere,atmosphere,hydrosphere,and biosphere.They are widely distributed throughout geological history and provide essential energy and mineral resources for the development of human society.They also record the evolution process of the earth and improve the understanding of the earth.This review focuses on the diagenesis and formation mechanisms of black shales sedimentation,composition,evolution,and reconstruction,which have had a significant impact on the formation and enrichment of shale oil and gas.In terms of sedimentary environment,black shales can be classified into three types:Marine,terrestrial,and marine-terrestrial transitional facies.The formation processes include mechanisms such as eolian input,hypopycnal flow,gravity-driven and offshore bottom currents.From a geological perspective,the formation of black shales is often closely related to global or regional major geological events.The enrichment of organic matter is generally the result of the interaction and coupling of several factors such as primary productivity,water redox condition,and sedimentation rate.In terms of evolution,black shales have undergone diagenetic evolution of inorganic minerals,thermal evolution of organic matter and hydrocarbon generation,interactions between organic matter and inorganic minerals,and pore evolution.In terms of reconstruction,the effects of fold deformation,uplift and erosion,and fracturing have changed the stress state of black shale reservoirs,thereby having a significant impact on the pore structure.Fluid activity promotes the formation of veins,and have changed the material composition,stress structure,and reservoir properties of black shales.Regarding resource effects,the deposition of black shales is fundamental for shale oil and gas resources,the evolution of black shales promotes the shale oil and gas formation and storage,and the reconstruction of black shales would have caused the heterogeneous distribution of oil and gas in shales.Exploring the formation mechanisms and interactions of black shales at different scales is a key to in-depth research on shale formation and evolution,as well as the key to revealing the mechanism controlling shale oil and gas accumulation.The present records can reveal how these processes worked in geological history,and improve our understanding of the coupling mechanisms among regional geological events,black shales evolution,and shale oil and gas formation and enrichment.展开更多
Volcanic arc degassing contributes significantly to atmospheric CO_(2)levels and therefore has a pivotal impact on paleoclimate changes.The Neo-Tethyan decarbonation subduction is thought to have played a major role in...Volcanic arc degassing contributes significantly to atmospheric CO_(2)levels and therefore has a pivotal impact on paleoclimate changes.The Neo-Tethyan decarbonation subduction is thought to have played a major role in Cenozoic climate changes,although there are still no quantifiable restrictions.Here we build past subduction scenarios using an improved seismic tomography reconstruction method and cal-culate the subducted slabflux in the India-Eurasia collision region.Wefind remarkable synchronicity between calculated slabflux and paleoclimate parameters in the Cenozoic,indicating a causal link between these processes.The closure of the Neo-Tethyan intra-oceanic subduction resulted in more carbon-rich sediments subducting along the Eurasia margin,as well as continental arc volcanoes,which further triggered global warming up to the Early Eocene Climatic Optimum.The abrupt termination of the Neo-Tethyan subduction due to the India-Eurasia collision could be the primary tectonic cause of the~50-40 Ma CO_(2)drop.The gradual decrease in atmospheric CO_(2)concentration after 40 Ma may be attributed to enhance continental weathering due to the growth of the Tibetan Plateau.Our results con-tribute to a better understanding of the dynamic implications of Neo-Tethyan Ocean evolution and may provide new constraints for future carbon cycle models.展开更多
Tectonic reconstructions of Proterozoic Australia commonly place the Peake and Denison Domain of the northeastern Gawler Craton at the interface between the North and South Australian cratons prior to the reconfigurat...Tectonic reconstructions of Proterozoic Australia commonly place the Peake and Denison Domain of the northeastern Gawler Craton at the interface between the North and South Australian cratons prior to the reconfiguration of Australia’s main tectonic components in the Mesoproterozoic.However,this reconstruction is largely based on palaeomagnetic data as the geological correlations between these regions are currently limited,particularly during the Mesoproterozoic.The early Mesoproterozoic period is significant as it corresponds to major IOCG mineralization in the eastern Gawler Craton between 1600 Ma and 1575 Ma,and IOCG mineralization in the Mount Isa Province largely between 1550 Ma and 1490 Ma.Therefore,determining the relationship of the Peake and Denison Domain to the Gawler Craton and Mount Isa Province during this period is essential to evaluating mineral prospectivity in the northeastern Gawler Craton.New U–Pb LA-ICP-MS geochronology on zircon and titanite improves our understanding of the tectonothermal and hydrothermal history the Peake and Denison Domain during the latePalaeoproterozoic,early-Mesoproterozoic and the Cambrian–Ordovician periods.Titanite formed within largely calc-silicate alteration assemblages indicates the Peake and Denison Domain has a protracted history of hydrothermal activity,recording events at c.1565 Ma,1530–1515 Ma,c.1500 Ma,c.1465 Ma and c.490 Ma.The highly calcic nature of the c.1565–1500 Ma alteration in the Peake and Denison Domain shares strong similarities in age and character to the regional calcic-sodic alteration recorded in the Mount Isa Province.We suggest the two regions were influenced by similar hydrothermal systems during the early Mesoproterozoic,supporting reconstruction models that place the Peake and Denison Domain near the Mount Isa Province during the early-Mesoproterozoic.This highlights the prospectivity of the Peake and Denison Domain for Isan-style IOCG mineralization,but requires consideration of the post-1500 Ma rotation of prospective structures.展开更多
文摘Collision and amalgamation of continent and microcontinent block were recognized as one of the major processes for building up a continent. The pre Jurassic structure of Northeast China and its adjacent region (including south of Russia Far East, north of North Korea and inner part of southwest Japan) is characterized by collision and amalgamation of microcontinent blocks, such as the North China block (NCB), Northeast China block (NECB), Khanka block and Hida block.The central Jilin belt and Yanbian Grodekovsk belt that juxtapose and amalgamate these blocks in between in Northeast China and its vicinity were formed by a series of rock assemblages that are typical for Paleozoic active continental margin island arcs. The dominant Permian marine sequences in Yanbian (Yanbian Grodekovsk) belt, which are known for bearing transitional marine fauna, include turbidite olistostrome sediments of a slope facies, and limestones, sandstones as well as siltstones of a neritic littoral facies sediments along with predominant acidic to intermediate volcanic materials. The Maizuru belt in southwest Japan is supposed to be the equivalent of Yanbian Grodekovsk belt. The central Jilin belt consists of a well developed sedimentary sequence and volcanics of Paleozoic. The Bamiantong Gudonghe Fuerhe Chongjin suture complex in Northeast China and the equivalent Sangun Akiyoshi belt in southwest Japan serve as a major suture zone among these microcontinental blocks and belts.
基金supported by the projects of the China Geological Survey(DD20230043,DD20240048)the project of the National Natural Science Foundation of China(42102123)。
文摘Black shales are important products of material cycling and energy exchange among the lithosphere,atmosphere,hydrosphere,and biosphere.They are widely distributed throughout geological history and provide essential energy and mineral resources for the development of human society.They also record the evolution process of the earth and improve the understanding of the earth.This review focuses on the diagenesis and formation mechanisms of black shales sedimentation,composition,evolution,and reconstruction,which have had a significant impact on the formation and enrichment of shale oil and gas.In terms of sedimentary environment,black shales can be classified into three types:Marine,terrestrial,and marine-terrestrial transitional facies.The formation processes include mechanisms such as eolian input,hypopycnal flow,gravity-driven and offshore bottom currents.From a geological perspective,the formation of black shales is often closely related to global or regional major geological events.The enrichment of organic matter is generally the result of the interaction and coupling of several factors such as primary productivity,water redox condition,and sedimentation rate.In terms of evolution,black shales have undergone diagenetic evolution of inorganic minerals,thermal evolution of organic matter and hydrocarbon generation,interactions between organic matter and inorganic minerals,and pore evolution.In terms of reconstruction,the effects of fold deformation,uplift and erosion,and fracturing have changed the stress state of black shale reservoirs,thereby having a significant impact on the pore structure.Fluid activity promotes the formation of veins,and have changed the material composition,stress structure,and reservoir properties of black shales.Regarding resource effects,the deposition of black shales is fundamental for shale oil and gas resources,the evolution of black shales promotes the shale oil and gas formation and storage,and the reconstruction of black shales would have caused the heterogeneous distribution of oil and gas in shales.Exploring the formation mechanisms and interactions of black shales at different scales is a key to in-depth research on shale formation and evolution,as well as the key to revealing the mechanism controlling shale oil and gas accumulation.The present records can reveal how these processes worked in geological history,and improve our understanding of the coupling mechanisms among regional geological events,black shales evolution,and shale oil and gas formation and enrichment.
基金supported by the National Natural Science Foundation of China(41888101 and 41625016)the Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(311021003)the National Key Research and Development Program of China(2022YFF0802800)。
文摘Volcanic arc degassing contributes significantly to atmospheric CO_(2)levels and therefore has a pivotal impact on paleoclimate changes.The Neo-Tethyan decarbonation subduction is thought to have played a major role in Cenozoic climate changes,although there are still no quantifiable restrictions.Here we build past subduction scenarios using an improved seismic tomography reconstruction method and cal-culate the subducted slabflux in the India-Eurasia collision region.Wefind remarkable synchronicity between calculated slabflux and paleoclimate parameters in the Cenozoic,indicating a causal link between these processes.The closure of the Neo-Tethyan intra-oceanic subduction resulted in more carbon-rich sediments subducting along the Eurasia margin,as well as continental arc volcanoes,which further triggered global warming up to the Early Eocene Climatic Optimum.The abrupt termination of the Neo-Tethyan subduction due to the India-Eurasia collision could be the primary tectonic cause of the~50-40 Ma CO_(2)drop.The gradual decrease in atmospheric CO_(2)concentration after 40 Ma may be attributed to enhance continental weathering due to the growth of the Tibetan Plateau.Our results con-tribute to a better understanding of the dynamic implications of Neo-Tethyan Ocean evolution and may provide new constraints for future carbon cycle models.
基金supported by ARC Linkage Project LP160100578(JLP and MH)the Mineral Exploration Cooperative Research Centre whose activities are funded by the Australian Government’s Cooperative Research Centre Programsupport of an Australian Government Research Training Program Stipend and LJM acknowledges the support of ARC DECRA Fellowship DE210101126.
文摘Tectonic reconstructions of Proterozoic Australia commonly place the Peake and Denison Domain of the northeastern Gawler Craton at the interface between the North and South Australian cratons prior to the reconfiguration of Australia’s main tectonic components in the Mesoproterozoic.However,this reconstruction is largely based on palaeomagnetic data as the geological correlations between these regions are currently limited,particularly during the Mesoproterozoic.The early Mesoproterozoic period is significant as it corresponds to major IOCG mineralization in the eastern Gawler Craton between 1600 Ma and 1575 Ma,and IOCG mineralization in the Mount Isa Province largely between 1550 Ma and 1490 Ma.Therefore,determining the relationship of the Peake and Denison Domain to the Gawler Craton and Mount Isa Province during this period is essential to evaluating mineral prospectivity in the northeastern Gawler Craton.New U–Pb LA-ICP-MS geochronology on zircon and titanite improves our understanding of the tectonothermal and hydrothermal history the Peake and Denison Domain during the latePalaeoproterozoic,early-Mesoproterozoic and the Cambrian–Ordovician periods.Titanite formed within largely calc-silicate alteration assemblages indicates the Peake and Denison Domain has a protracted history of hydrothermal activity,recording events at c.1565 Ma,1530–1515 Ma,c.1500 Ma,c.1465 Ma and c.490 Ma.The highly calcic nature of the c.1565–1500 Ma alteration in the Peake and Denison Domain shares strong similarities in age and character to the regional calcic-sodic alteration recorded in the Mount Isa Province.We suggest the two regions were influenced by similar hydrothermal systems during the early Mesoproterozoic,supporting reconstruction models that place the Peake and Denison Domain near the Mount Isa Province during the early-Mesoproterozoic.This highlights the prospectivity of the Peake and Denison Domain for Isan-style IOCG mineralization,but requires consideration of the post-1500 Ma rotation of prospective structures.
