Based on our study of the nature and variation of mineralization-controlling faults in their deep extension and the spatial distribution of gold orebodies in the northwestern Shandong Peninsula (NSP), here we propose ...Based on our study of the nature and variation of mineralization-controlling faults in their deep extension and the spatial distribution of gold orebodies in the northwestern Shandong Peninsula (NSP), here we propose that the gold deposits in the Jiaojia gold belt are controlled by listric faults and the gold deposits in the NSP are controlled by extensional fault system. We also suggest that there is a multiple mineralization space in the deep part of the NSP gold belt. As steps or benches occur along the deep extention of the listric fault where its dipping angle changes from steep to gentle, a number of gold deposits are correspondingly distributed as a steplike pattern, which is named as a step metallogenetic model for gold deposits in the NSP. The gold deposits in Shandong Peninsula were formed in the Cretaceous when the crust in the region experienced extention and thinning following the strong collision between North China Plate and Yangtze Plate during the Triassic. Crust anataxis, fluid remobilization, and extention-detachement of the crust are the leading factors for the gold mineralization.展开更多
The paper presents an overview of the relationships between the interior structures of tectonic terranes and the distribution of tectonic-metallogenic zones in Southeast Asia. Episodic tectonic activities occurred in ...The paper presents an overview of the relationships between the interior structures of tectonic terranes and the distribution of tectonic-metallogenic zones in Southeast Asia. Episodic tectonic activities occurred in this archipelagic area, generating metallogenic belts in multi-terranes. Since the Late Paleozoic, opening and closure of the Paleotethys and Neotethys led to multiple suture zones between different blocks, mainly between the Indochina terrane, the Nambung terrane, the Sibumasu terrane and the West Myanmar terrane. During the Mesozoic to Cenozoic, the formation of accreted terranes and their related islands was caused by subduction and collision processes between the Pacific and Australian plates toward the Eurasian Continent, forming Sundaland and its affiliated islands, the Philippines and its subsidiary islands, the Papua New Guinea terrane and its related islands and the Sunda epicontinental arc system. Within the margin of terranes resulted in the structural transfer zones, their secondary tectonic units can be divided into island arc belts, back-arc basins, suture zones, marginal fold belts and orogenic belts. The metallogenic assemblages are mainly distributed within these structural zones of the terranes. According to the relationship between these tectonic units and the distribution of mineral resources, the tectonic-metallogenic belts can be divided into 24 metallogenic belts in Southeast Asia. They are characterized by a diversity and frequency of metallogenic material combination which is likely to reflect the complexity of the material distribution during mineralization processes, mostly by the structural transformation during the dissociation-convergence process between multiple terranes. Therefore, the formation of ore deposits was not only restricted by the evolution(opening and closure) of Paleo-and Neotethys, but may also be controlled by the interaction of the terranes with different tectonic attributes which provided multiple sources of metallogenic material.展开更多
The alkali-rich rocks, spreading along the suture zone of Jingsha River, refer to the alkali-rich porphyry rocks, which emplace during the Himalaya epoch in northwest of Yunnan Province, and consist of syenit, syenit ...The alkali-rich rocks, spreading along the suture zone of Jingsha River, refer to the alkali-rich porphyry rocks, which emplace during the Himalaya epoch in northwest of Yunnan Province, and consist of syenit, syenit porphyry, monzonite porphyry and granite porphyry. Petrological chemical analysis results suggest that silica is poor and aluminum is rich, and high potassium large ion lithophile elements （LILE）, light rare earth element （LREE） and Sr are obviously detracted in these rocks. High field strength elements （HFSE） and heavy rare earth element （HREE） are depleted, especially Nb, Ta, P and Ti. 8Eu： 0.09--1.64 shows that plagioclase does not appear fractional crystallization during the formation of alkali-rich rocks, t^348, H and O isotopes and Pb isotopes suggest that ore-forming fluid is derived from the mantle, and Pb is possibly mixed by mantle, wall rock and crust. The age of Pb in alkali-rich rocks is about 250-220 Ma. The age of alkali porphyry rock （dykes） varies from 30 Ma to 50 Ma. Alkali rocks have strong metallogenetic relation. Au mineralization is associated to the alkali magrnatic activities with a relatively high temperature, low pressure and high oxygen fugacity. However, copper mineralization is mainly associated with alkali-sub-alkali magmatic activities in a process of relatively low temperature, high pressure and lower oxygen fugacity.展开更多
文摘Based on our study of the nature and variation of mineralization-controlling faults in their deep extension and the spatial distribution of gold orebodies in the northwestern Shandong Peninsula (NSP), here we propose that the gold deposits in the Jiaojia gold belt are controlled by listric faults and the gold deposits in the NSP are controlled by extensional fault system. We also suggest that there is a multiple mineralization space in the deep part of the NSP gold belt. As steps or benches occur along the deep extention of the listric fault where its dipping angle changes from steep to gentle, a number of gold deposits are correspondingly distributed as a steplike pattern, which is named as a step metallogenetic model for gold deposits in the NSP. The gold deposits in Shandong Peninsula were formed in the Cretaceous when the crust in the region experienced extention and thinning following the strong collision between North China Plate and Yangtze Plate during the Triassic. Crust anataxis, fluid remobilization, and extention-detachement of the crust are the leading factors for the gold mineralization.
基金financially supported by the Natural Science Foundation of China (Nos. 41573039 41673040 U1603245)
文摘The paper presents an overview of the relationships between the interior structures of tectonic terranes and the distribution of tectonic-metallogenic zones in Southeast Asia. Episodic tectonic activities occurred in this archipelagic area, generating metallogenic belts in multi-terranes. Since the Late Paleozoic, opening and closure of the Paleotethys and Neotethys led to multiple suture zones between different blocks, mainly between the Indochina terrane, the Nambung terrane, the Sibumasu terrane and the West Myanmar terrane. During the Mesozoic to Cenozoic, the formation of accreted terranes and their related islands was caused by subduction and collision processes between the Pacific and Australian plates toward the Eurasian Continent, forming Sundaland and its affiliated islands, the Philippines and its subsidiary islands, the Papua New Guinea terrane and its related islands and the Sunda epicontinental arc system. Within the margin of terranes resulted in the structural transfer zones, their secondary tectonic units can be divided into island arc belts, back-arc basins, suture zones, marginal fold belts and orogenic belts. The metallogenic assemblages are mainly distributed within these structural zones of the terranes. According to the relationship between these tectonic units and the distribution of mineral resources, the tectonic-metallogenic belts can be divided into 24 metallogenic belts in Southeast Asia. They are characterized by a diversity and frequency of metallogenic material combination which is likely to reflect the complexity of the material distribution during mineralization processes, mostly by the structural transformation during the dissociation-convergence process between multiple terranes. Therefore, the formation of ore deposits was not only restricted by the evolution(opening and closure) of Paleo-and Neotethys, but may also be controlled by the interaction of the terranes with different tectonic attributes which provided multiple sources of metallogenic material.
基金Project(1343-74334000019) supported by the PhD Innovation Subject of Central south University,ChinaProject(1960-71131100088 (CX2010B085)) supported by the Hunan Provincial Innovation Foundation For Postgraduate Students,China
文摘The alkali-rich rocks, spreading along the suture zone of Jingsha River, refer to the alkali-rich porphyry rocks, which emplace during the Himalaya epoch in northwest of Yunnan Province, and consist of syenit, syenit porphyry, monzonite porphyry and granite porphyry. Petrological chemical analysis results suggest that silica is poor and aluminum is rich, and high potassium large ion lithophile elements （LILE）, light rare earth element （LREE） and Sr are obviously detracted in these rocks. High field strength elements （HFSE） and heavy rare earth element （HREE） are depleted, especially Nb, Ta, P and Ti. 8Eu： 0.09--1.64 shows that plagioclase does not appear fractional crystallization during the formation of alkali-rich rocks, t^348, H and O isotopes and Pb isotopes suggest that ore-forming fluid is derived from the mantle, and Pb is possibly mixed by mantle, wall rock and crust. The age of Pb in alkali-rich rocks is about 250-220 Ma. The age of alkali porphyry rock （dykes） varies from 30 Ma to 50 Ma. Alkali rocks have strong metallogenetic relation. Au mineralization is associated to the alkali magrnatic activities with a relatively high temperature, low pressure and high oxygen fugacity. However, copper mineralization is mainly associated with alkali-sub-alkali magmatic activities in a process of relatively low temperature, high pressure and lower oxygen fugacity.
