| 云南金属矿床的分布和成因 |
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| 引用本文：.1983.The Distribution And Genesis Of Metallic Ore Deposits In Yunnan Province[J].Mineral Deposits,2(4):19~25 |
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| The Distribution And Genesis Of Metallic Ore Deposits In Yunnan Province |
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| Abstract:Geotectonically, Yunnan Province lies in southwest edge of the South China Plate and is also close to east side of the subduction zone of the Indian Plate underthrusting northeastward. During the geologic time, it underwent orogenies of various periods, mainly Proterozoic Jinning and Chengjiang movements, Paleozoic Caledonian and Variscan orogenies, Mesozoic Indo-Sinian and Yerrshanian movements, and Cenozoic Himalayan movment, forming as a result five belts of metamorphic rocks called preferably five structural framework belts, i.e, Wenshan continental margin, Kangdian earth's axis, Shigu-Diancangshan-Ailoushan, Lancangjiang and Gauligongshan. Areas between these belts are named “inter-framework terrains”. Magmatic activities took place eleven times from Luliang movement to Himalayan movement, and emplacement and effusion of intermediate-acid and basic-ultrabasic magmas seem to have occurred mostly on these structural framework belts, sometimes in the form of zones. The major metallic ore deposits observed in the structural framework belts are stratiform iron and copper deposits, nickel, cobalt, gold and platinum deposits, chromite deposits, vanadium-titanium iron deposits, and tin, tungsten and beryllium deposits. The inter-framework terrains are dominated by lead-zinc polymetallic deposits, copper-bearing sandstone type ore deposits, mercury and antimony deposits. sedimentation- transformation type iron deposits, bauxite deposits and manganese deposits. The transitional zone between and the border areas of these two structrual units possess chiefly tin, tungsten, bismuth, molybdenum and beryllium deposits, porphyry copper and molybdenum deposits, and lead-zinc deposits. These deposits seem related in time and space to certain stratigraphic, petrograph.ic and igneous features. As for the genesis of metallic ore deposits in Yunnan Province, the author holds the opinion that the structural framework belts, being actually erosional areas in different geologic periods, supplied exogenic and metamorphic metallic ore deposits in ancient sea and lake basin of inter-framework terrains with part of metallogenic materials, which were probably supplemented with some volcanic materials. Under the suitable integrated physical-chemical and paleogeographic conditions, metallogenic materials were first concentrated in specified stratigraphic position and sedimentary facies and then, through the process of diagenesis and transformation, further accumulated into ore deposits. Tin and tungsten deposits are connected in genesis primarily with transformation type and partly with syntectic type granites. During its formation and emplacement, the magma contaminated, assimilated and replaced the country rock and captured certain amounts of metallogenic elements. As a result, ore deposits were formed under favorable structural and petrographic conditions. Porphyry copper and molybdenum deposits are genetically related to intermediate-acid subvolcanic porphyries. Metallization of Yunnan Province is characterized by polystages, polytypes and polygeneses, which is attributed to its geotectonic position (concentration of polycycle orogenies), the multiple magmatic activities it underwent, the remarkably high tin and tungsten abundances of its crust, and some other factors. In the present paper, this sort of metallogenic process is terminologically named "metallization of deep sources evolution" . |
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