1927年7月,中(国)瑞(典)西北科学考察团团员、地质学家丁道衡发现了白云鄂博矿床,以世界第一的稀土资源储量奠定了我国在全球稀土格局中的战略地位(Weng Zhehan et al.,2015)。稀土被称为“工业维生素”或“万能之土”,已经成为当今最...1927年7月,中(国)瑞(典)西北科学考察团团员、地质学家丁道衡发现了白云鄂博矿床,以世界第一的稀土资源储量奠定了我国在全球稀土格局中的战略地位(Weng Zhehan et al.,2015)。稀土被称为“工业维生素”或“万能之土”,已经成为当今最重要的战略性关键资源(王登红等,2019),也是全球主要大国竞争和博弈的重要焦点(王安建等,2022)。展开更多
Numerous intermediate to felsic igneous rocks are present in both subduction and collisional orogens.However,porphyry copper deposits(PCDs)are comparatively rare.The underlying factors that differentiate fertile magma...Numerous intermediate to felsic igneous rocks are present in both subduction and collisional orogens.However,porphyry copper deposits(PCDs)are comparatively rare.The underlying factors that differentiate fertile magmas,which give rise to PCDs,from barren magmas in a specific geological setting are not well understood.In this study,three supervised machine learning algorithms:random forest(RF),logistic regression(LR)and support vector machine(SVM)were employed to classify metallogenic fertility in southeastern Tibet,Sanjiang orogenic belt,based on whole-rock trace element and Sr-Nd isotopic ratios.The performance of the RF model is better than LR and SVM models.Feature importance analysis of the models reveals that the concentration of Y,Eu,and Th,along with Sr-Nd isotope compositions are crucial variables in distinguishing fertile and barren samples.However,when the optimized models were applied to predict the datasets of Miocene Gangdese porphyry copper belt and Jurassic Gangdese arc representing collision and subduction settings respectively,a marked decline in metrics occurred in all three models,particularly on the subduction dataset.This substantial decrease indicates the compositional characteristics of intrusions across different tectonic settings could be diverse in a multidimensional space,highlighting the complex interplay of geological factors influencing PCD’s formation.展开更多
Metallogenic research on structural levels can reveal vertical patterns of mineralization and facilitate the deep exploration of economic minerals.However,research focusing on the correlation between structural levels...Metallogenic research on structural levels can reveal vertical patterns of mineralization and facilitate the deep exploration of economic minerals.However,research focusing on the correlation between structural levels and mineralization remains limited.In this study,we summarize the deformation patterns and associated mineral deposits observed at different crustal levels(i.e.,surface,shallow,middle,and deep structural levels,corresponding to depths of<2,2-8,8-15,and>15 km,respectively).Furthermore,we examine the genetic association between structural levels and metallogenesis,demonstrating that distinct structural levels are linked to specific types of mineralization.Key factors that vary across crustal levels include temperature,pressure,and fluid circulation.Ore-forming processes involve interactions between structures and fluids under varying temperatures and pressures.Structural levels influence mineralization by controlling the temperatures,pressures,and deformation mechanisms that drive the activation,migration,and enrichment of ore-forming materials.展开更多
A subducted continental slab is sometimes torn during collision,yet the exact impact of slab-tearing on the overlying lithosphere remains unclear.Here,we image the structure and architecture of the Asian lithosphere a...A subducted continental slab is sometimes torn during collision,yet the exact impact of slab-tearing on the overlying lithosphere remains unclear.Here,we image the structure and architecture of the Asian lithosphere above the Indian slab in the eastern Tibetan Plateau using multiscale seismic tomography models and zircon Hf isotopic mapping,respectively.Our mantle V_(p)model shows that a large low-velocity anomaly extends laterally beneath the thinned Asian lithosphere above the tear zone roughly along the 26°N.The V_(s)images,magmatic records and Hf isotopic mapping indicate that this low-velocity anomaly recorded an asthenosphere flow eastward along the tear zone,which thermally eroded and refertilized the overlying Asian lithosphere,leading to the lithospheric melting,thinning and root delaminating.The vertical tear also generated a tectonic weak zone with associated Cenozoic potassic and carbonatitic magma suites.We argue that such a hot lithosphere discontinuity provided a reasonable mechanism for the abrupt change of crust thickness and the transformation of crust-mantle deformation from coupling to decoupling across the tear zone.展开更多
文摘1927年7月,中(国)瑞(典)西北科学考察团团员、地质学家丁道衡发现了白云鄂博矿床,以世界第一的稀土资源储量奠定了我国在全球稀土格局中的战略地位(Weng Zhehan et al.,2015)。稀土被称为“工业维生素”或“万能之土”,已经成为当今最重要的战略性关键资源(王登红等,2019),也是全球主要大国竞争和博弈的重要焦点(王安建等,2022)。
基金financially supported by the National Key Research and Development Program of China(2019YFA0708602,2022YFF0800903)National Natural Science Foundation of China(42472112,U2244217,41973045)+1 种基金Basic Science and Technology Research Fundings of the Institute of Geology,CAGS(JKYZD202312)Geological Survey Projects of the China Geological Survey(DD20242878,DD20243512).
文摘Numerous intermediate to felsic igneous rocks are present in both subduction and collisional orogens.However,porphyry copper deposits(PCDs)are comparatively rare.The underlying factors that differentiate fertile magmas,which give rise to PCDs,from barren magmas in a specific geological setting are not well understood.In this study,three supervised machine learning algorithms:random forest(RF),logistic regression(LR)and support vector machine(SVM)were employed to classify metallogenic fertility in southeastern Tibet,Sanjiang orogenic belt,based on whole-rock trace element and Sr-Nd isotopic ratios.The performance of the RF model is better than LR and SVM models.Feature importance analysis of the models reveals that the concentration of Y,Eu,and Th,along with Sr-Nd isotope compositions are crucial variables in distinguishing fertile and barren samples.However,when the optimized models were applied to predict the datasets of Miocene Gangdese porphyry copper belt and Jurassic Gangdese arc representing collision and subduction settings respectively,a marked decline in metrics occurred in all three models,particularly on the subduction dataset.This substantial decrease indicates the compositional characteristics of intrusions across different tectonic settings could be diverse in a multidimensional space,highlighting the complex interplay of geological factors influencing PCD’s formation.
基金supported by National Key Research and Development Program of China(Grant Nos.2022YFF0800903 and 2024YFC2909905)the National Natural Science Foundation of China(NSFC)(Grant Nos.42261144669,42262026,and 42273073).
文摘Metallogenic research on structural levels can reveal vertical patterns of mineralization and facilitate the deep exploration of economic minerals.However,research focusing on the correlation between structural levels and mineralization remains limited.In this study,we summarize the deformation patterns and associated mineral deposits observed at different crustal levels(i.e.,surface,shallow,middle,and deep structural levels,corresponding to depths of<2,2-8,8-15,and>15 km,respectively).Furthermore,we examine the genetic association between structural levels and metallogenesis,demonstrating that distinct structural levels are linked to specific types of mineralization.Key factors that vary across crustal levels include temperature,pressure,and fluid circulation.Ore-forming processes involve interactions between structures and fluids under varying temperatures and pressures.Structural levels influence mineralization by controlling the temperatures,pressures,and deformation mechanisms that drive the activation,migration,and enrichment of ore-forming materials.
基金supported by the National Natural Science Foundation of China(92462304)National Key Technologies R&D Program(2022YFF0800903)。
文摘A subducted continental slab is sometimes torn during collision,yet the exact impact of slab-tearing on the overlying lithosphere remains unclear.Here,we image the structure and architecture of the Asian lithosphere above the Indian slab in the eastern Tibetan Plateau using multiscale seismic tomography models and zircon Hf isotopic mapping,respectively.Our mantle V_(p)model shows that a large low-velocity anomaly extends laterally beneath the thinned Asian lithosphere above the tear zone roughly along the 26°N.The V_(s)images,magmatic records and Hf isotopic mapping indicate that this low-velocity anomaly recorded an asthenosphere flow eastward along the tear zone,which thermally eroded and refertilized the overlying Asian lithosphere,leading to the lithospheric melting,thinning and root delaminating.The vertical tear also generated a tectonic weak zone with associated Cenozoic potassic and carbonatitic magma suites.We argue that such a hot lithosphere discontinuity provided a reasonable mechanism for the abrupt change of crust thickness and the transformation of crust-mantle deformation from coupling to decoupling across the tear zone.
