The geotectonic setting refers to the three-dimensional space and relatedevents based on which a metallogenic system is formed and an ore-forming process takes place. Thispaper discusses the tectonic evolution of the ...The geotectonic setting refers to the three-dimensional space and relatedevents based on which a metallogenic system is formed and an ore-forming process takes place. Thispaper discusses the tectonic evolution of the southwestern margin of the North China paleocontinentand related geotectonic settings in which large or superlarge deposits are formed. Emphasis is puton the geodynamic conditions of the Jinchuan nickel-copper deposit, the Baiyin copper-polymetallicdeposit and the Hanshan gold deposit. It is significant that the three deposits occur together as a'trinity' on the same paleocontinental margin. The Jinchuan nickel-copper deposit was formed duringthe early stage of rifting of the paleocontinental margin; the Baiyin copper-polymetallic depositwas formed during the splitting stage of a continental-margin arc. The continental-margin arcspitting resulted in an 'island arc rift' in the early stage of evolution. The Hanshan gold depositwas formed within the Altun sinistral strike-slip fault system and its provenance is the'intraoceanic arc' volcanic rocks.展开更多
The newly discovered early Paleozoic Delenuoer ophiolite,in the western margin of the Central Qilian Shan,is composed of serpentinized peridotite,cumulate gabbro,diabase,massive basalt,and pillow basalt.This study pre...The newly discovered early Paleozoic Delenuoer ophiolite,in the western margin of the Central Qilian Shan,is composed of serpentinized peridotite,cumulate gabbro,diabase,massive basalt,and pillow basalt.This study presents geochronological and geochemical data for the cumulate gabbro and basalt.LA-ICP-MS U-Pb dating of zircons from the cumulate gabbro yielded a magmatic crystallization age of 472±4 Ma.The basalts have normal mid-ocean ridge basalt(N-MORB)compositions and a narrow range ofεNd(t)values(+4.5 to+5.3),which indicates they were derived from a depleted mantle source.On the basis of regional geological constraints,it is proposed that the Delenuoer ophiolite is a westward extension of the South Ophiolite Belt(Yushigou-Youhulugou-Donggou-Dongcaohe Ophiolite Belt)in the North Qilian Shan.The Delenuoer ophiolite,along with the Gulangxia-Delenuoer fault,defines the westernmost part of the tectonic boundary between the North and Central Qilian Shan.This ophiolite may have formed during southward subduction of the Qilian Ocean slab during the early Paleozoic.展开更多
The mountain watersheds of Kaidu River and Urumqi River, which separately originate from the south and north-side of the Tianshan Mountains in Xinjiang, are selected as the study area. The characteristics and trends o...The mountain watersheds of Kaidu River and Urumqi River, which separately originate from the south and north-side of the Tianshan Mountains in Xinjiang, are selected as the study area. The characteristics and trends on variation of temperature, precipitation and runoff, and the correlativity between temperature, precipitation, and runoffwere analyzed based on the past 40 years of observational data from the correlative hydrological and weather stations in the study areas. Various weather scene combinations are assumed and the response models of runoff to climate change are established in order to evaluate the sensitivity of runoff to climate change in the study areas based on the foregoing analysis, Results show that all variations of temperature, precipitation, and runoff overall present an oscillating and increasing trend since the 1960s and this increase are quite evident after 1990. There is a markedly positive correlation between mountain runoff, temperature, and precipitation while there are obvious regional differences of responding degree to precipitation and temperature between mountain runoff of Ummqi River and Kaidu River Basins Also, mountain runoff of Urumqi River Basin is more sensitive to precipitation change than that of Kaidu River Basin, and mountain runoff of Kaidu River Basin is more sensitive to temperature change than that of Ummqi River Basin.展开更多
Using SHRIMP zircon U-Pb dating methods and cathodoluminescence (CL) technique, we have pre- cisely dated ore samples from tungsten ore deposit, ore-bearing volcanic-sedimentary strata and granite in the Yushan region...Using SHRIMP zircon U-Pb dating methods and cathodoluminescence (CL) technique, we have pre- cisely dated ore samples from tungsten ore deposit, ore-bearing volcanic-sedimentary strata and granite in the Yushan region within the east Tianshan-Beishan W-bearing zone. This study reveals Yu- shan tungsten ore deposit zone formed in 250 ± 9 Ma, and it is closely associated with the Permian granites and felsic volcanic rocks. This new type of tungsten ore deposit in the east Tianshan-Beishang multiple-metallogenetic province may probably be associated with the regionally right-literal shearing after the main Carboniferous collisional orogeny, and the formation of pull-apart basin and the felsic magmatism.展开更多
文摘The geotectonic setting refers to the three-dimensional space and relatedevents based on which a metallogenic system is formed and an ore-forming process takes place. Thispaper discusses the tectonic evolution of the southwestern margin of the North China paleocontinentand related geotectonic settings in which large or superlarge deposits are formed. Emphasis is puton the geodynamic conditions of the Jinchuan nickel-copper deposit, the Baiyin copper-polymetallicdeposit and the Hanshan gold deposit. It is significant that the three deposits occur together as a'trinity' on the same paleocontinental margin. The Jinchuan nickel-copper deposit was formed duringthe early stage of rifting of the paleocontinental margin; the Baiyin copper-polymetallic depositwas formed during the splitting stage of a continental-margin arc. The continental-margin arcspitting resulted in an 'island arc rift' in the early stage of evolution. The Hanshan gold depositwas formed within the Altun sinistral strike-slip fault system and its provenance is the'intraoceanic arc' volcanic rocks.
基金funded by the Science and Technology Major Project of Gansu Province(No.1002FKDA04)the Fundamental Research Funds for the Central Universities,China(Lzujbky2016-197,Lzujbky2018it20)the National Nature Science Foundation of China(No.41702044)。
文摘The newly discovered early Paleozoic Delenuoer ophiolite,in the western margin of the Central Qilian Shan,is composed of serpentinized peridotite,cumulate gabbro,diabase,massive basalt,and pillow basalt.This study presents geochronological and geochemical data for the cumulate gabbro and basalt.LA-ICP-MS U-Pb dating of zircons from the cumulate gabbro yielded a magmatic crystallization age of 472±4 Ma.The basalts have normal mid-ocean ridge basalt(N-MORB)compositions and a narrow range ofεNd(t)values(+4.5 to+5.3),which indicates they were derived from a depleted mantle source.On the basis of regional geological constraints,it is proposed that the Delenuoer ophiolite is a westward extension of the South Ophiolite Belt(Yushigou-Youhulugou-Donggou-Dongcaohe Ophiolite Belt)in the North Qilian Shan.The Delenuoer ophiolite,along with the Gulangxia-Delenuoer fault,defines the westernmost part of the tectonic boundary between the North and Central Qilian Shan.This ophiolite may have formed during southward subduction of the Qilian Ocean slab during the early Paleozoic.
基金supported by the funding of the Key Laboratory of Eco-hydrology Open FundChinese Academy of Sciences and Knowledge Innovation Program of the Chinese Academy of Sciences, No.KZCX2-YW-328
文摘The mountain watersheds of Kaidu River and Urumqi River, which separately originate from the south and north-side of the Tianshan Mountains in Xinjiang, are selected as the study area. The characteristics and trends on variation of temperature, precipitation and runoff, and the correlativity between temperature, precipitation, and runoffwere analyzed based on the past 40 years of observational data from the correlative hydrological and weather stations in the study areas. Various weather scene combinations are assumed and the response models of runoff to climate change are established in order to evaluate the sensitivity of runoff to climate change in the study areas based on the foregoing analysis, Results show that all variations of temperature, precipitation, and runoff overall present an oscillating and increasing trend since the 1960s and this increase are quite evident after 1990. There is a markedly positive correlation between mountain runoff, temperature, and precipitation while there are obvious regional differences of responding degree to precipitation and temperature between mountain runoff of Ummqi River and Kaidu River Basins Also, mountain runoff of Urumqi River Basin is more sensitive to precipitation change than that of Kaidu River Basin, and mountain runoff of Kaidu River Basin is more sensitive to temperature change than that of Ummqi River Basin.
基金the National Natural Science Foundation of China (Grant No. 40572045)the State Key Laboratory of Geological Processes and Mineral Re-sources in China University of Geosciences (GPMR0543)the research project ‘The study of metallization of ore deposits in Gansu Province’ in Gansu Geology and Mineral Resources Bureau
文摘Using SHRIMP zircon U-Pb dating methods and cathodoluminescence (CL) technique, we have pre- cisely dated ore samples from tungsten ore deposit, ore-bearing volcanic-sedimentary strata and granite in the Yushan region within the east Tianshan-Beishan W-bearing zone. This study reveals Yu- shan tungsten ore deposit zone formed in 250 ± 9 Ma, and it is closely associated with the Permian granites and felsic volcanic rocks. This new type of tungsten ore deposit in the east Tianshan-Beishang multiple-metallogenetic province may probably be associated with the regionally right-literal shearing after the main Carboniferous collisional orogeny, and the formation of pull-apart basin and the felsic magmatism.
