The Lanping Basin in the Nujiang-Lancangjiang-Jinshajiang (the Sanjiang) area of northeastern margin of the Tibetan Plateau is an important part of eastern Tethyan metallogenic domain. This basin hosts a number of l...The Lanping Basin in the Nujiang-Lancangjiang-Jinshajiang (the Sanjiang) area of northeastern margin of the Tibetan Plateau is an important part of eastern Tethyan metallogenic domain. This basin hosts a number of large unique sediment-hosted Pb-Zn polymetallic deposits or ore districts, such as the Baiyangping ore concentration area which is one of the representative ore district. The Baiyangping ore concentration area can be divided into the east and west ore belts, which were formed in a folded tectogene of the India-Asia continental coUisional setting and was controlled by a large reverse fault. Field observations reveal that the Mesozoic and Cenozoic sedimentary strata were outcropped in the mining area, and that the orebodies are obviously controlled by faults and hosted in sandstone and carbonate rocks. However, the oreforming elements in the east ore belt are mainly Pb-Zn -Sr-Ag, while Pb-Zn-Ag-Cu-Co elements are dominant in the west ore belt. Comparative analysis of the C-O-Sr-S-Pb isotopic compositions suggest that both ore belts had a homogeneous carbon source, and the carbon in hydrothermal calcite is derived from the dissolution of carbonate rock strata; the ore- forming fluids were originated from formation water and precipitate water, which belonged to basin brine fluid system; sulfur was from organic thermal chemical sulfate reduction and biological sulfate reduction; the metal mineralization material was from sedimentary strata and basement, but the difference of the material source of the basement and the strata and the superimposed mineralization of the west ore belt resulted in the difference of metallogenic elements between the eastern and western metallogenic belts. The Pb-Zn mineralization age of both ore belts was contemporary and formed in the same metaliogenetic event. Both thrust formed at the same time and occurred at the Early Oligocene, which is consistent with the age constrained by field geological relationship.展开更多
Qingchengzi ore concentration area in Liao-Ji rift is an important lead-zinc ore area of China,and the deep prospecting in this area has great prospects.Based on the spatial occurrence of ore bodies the Pb-Zn deposit ...Qingchengzi ore concentration area in Liao-Ji rift is an important lead-zinc ore area of China,and the deep prospecting in this area has great prospects.Based on the spatial occurrence of ore bodies the Pb-Zn deposit can be divided into three types:layered,vein-shaped and pinnate.The deep geological conditions in this area are deduced by analyzing the tectonic evolution process and rock mass gravity inversion.The tectonic evolution of Liao-Ji rift can be divided into three stages:Paleoproterozoic extension period,Mesoproterozoic compression period and Mesozoic reactivation period.The magmatic activities in the Indosinian epoch led to the distribution pattern of the present deposits.According to the gravity inversion,Shuangdinggou-and Xinling rock masses on the north and south sides of the mining area are connected in the deep.The connected rock body might be distributed in the entire mining area.Xinling rock mass may be a branch extending from Shuangdinggou rock mass along the northeast trending fault,the connected rocks provide magmatic hydrothermal fluid for the final,folds and faults result in different types of ore body shapes.展开更多
The newly-discovered Xiyi lead-zinc deposit is a large deposit located in the north central Baoshan block of the southern Sanjiang metallogenic belt section, Southwest China.The surface of the deposit is mainly covere...The newly-discovered Xiyi lead-zinc deposit is a large deposit located in the north central Baoshan block of the southern Sanjiang metallogenic belt section, Southwest China.The surface of the deposit is mainly covered by eluvial-deluvial lateritic layer, without any mineralized outcrops. The main concealed orebody V3 is buffed in the depth of 300-500m. The orebodies are controlled by certain stratigraphic horizons, and most are cut by strata with a high angle, while a few occur along the strata. The direct wall rocks are calcisiltite, calclithite, bioclastic calcarenite,展开更多
基金granted by the National Natural Science Foundation of China(grants No.41302067,41472067 and 41403043)the Fundamental Research Funds of Chinese Academy of Geological Sciences(grant No.YYWF201614 and 09 program of Institute of Geomechanics)IGCP/SIDA–600,and China Geological Survey(grant No.DD20160053)
文摘The Lanping Basin in the Nujiang-Lancangjiang-Jinshajiang (the Sanjiang) area of northeastern margin of the Tibetan Plateau is an important part of eastern Tethyan metallogenic domain. This basin hosts a number of large unique sediment-hosted Pb-Zn polymetallic deposits or ore districts, such as the Baiyangping ore concentration area which is one of the representative ore district. The Baiyangping ore concentration area can be divided into the east and west ore belts, which were formed in a folded tectogene of the India-Asia continental coUisional setting and was controlled by a large reverse fault. Field observations reveal that the Mesozoic and Cenozoic sedimentary strata were outcropped in the mining area, and that the orebodies are obviously controlled by faults and hosted in sandstone and carbonate rocks. However, the oreforming elements in the east ore belt are mainly Pb-Zn -Sr-Ag, while Pb-Zn-Ag-Cu-Co elements are dominant in the west ore belt. Comparative analysis of the C-O-Sr-S-Pb isotopic compositions suggest that both ore belts had a homogeneous carbon source, and the carbon in hydrothermal calcite is derived from the dissolution of carbonate rock strata; the ore- forming fluids were originated from formation water and precipitate water, which belonged to basin brine fluid system; sulfur was from organic thermal chemical sulfate reduction and biological sulfate reduction; the metal mineralization material was from sedimentary strata and basement, but the difference of the material source of the basement and the strata and the superimposed mineralization of the west ore belt resulted in the difference of metallogenic elements between the eastern and western metallogenic belts. The Pb-Zn mineralization age of both ore belts was contemporary and formed in the same metaliogenetic event. Both thrust formed at the same time and occurred at the Early Oligocene, which is consistent with the age constrained by field geological relationship.
基金Supported by the National Science Foundation for Distinguished Young Scholars of China(No.41502309)。
文摘Qingchengzi ore concentration area in Liao-Ji rift is an important lead-zinc ore area of China,and the deep prospecting in this area has great prospects.Based on the spatial occurrence of ore bodies the Pb-Zn deposit can be divided into three types:layered,vein-shaped and pinnate.The deep geological conditions in this area are deduced by analyzing the tectonic evolution process and rock mass gravity inversion.The tectonic evolution of Liao-Ji rift can be divided into three stages:Paleoproterozoic extension period,Mesoproterozoic compression period and Mesozoic reactivation period.The magmatic activities in the Indosinian epoch led to the distribution pattern of the present deposits.According to the gravity inversion,Shuangdinggou-and Xinling rock masses on the north and south sides of the mining area are connected in the deep.The connected rock body might be distributed in the entire mining area.Xinling rock mass may be a branch extending from Shuangdinggou rock mass along the northeast trending fault,the connected rocks provide magmatic hydrothermal fluid for the final,folds and faults result in different types of ore body shapes.
文摘The newly-discovered Xiyi lead-zinc deposit is a large deposit located in the north central Baoshan block of the southern Sanjiang metallogenic belt section, Southwest China.The surface of the deposit is mainly covered by eluvial-deluvial lateritic layer, without any mineralized outcrops. The main concealed orebody V3 is buffed in the depth of 300-500m. The orebodies are controlled by certain stratigraphic horizons, and most are cut by strata with a high angle, while a few occur along the strata. The direct wall rocks are calcisiltite, calclithite, bioclastic calcarenite,