Objective The Mengyejing potash deposit in the Simao Basin is the only producing area of solid potash at present in China. There is still controversy about the material source and distribution of the potash in this d...Objective The Mengyejing potash deposit in the Simao Basin is the only producing area of solid potash at present in China. There is still controversy about the material source and distribution of the potash in this deposit （Shen Lijian et al., 2017）, which has influenced not only the prospecting direction and efficiency but also the understanding of the control of Tethys tectonic evolution on the formation and distribution of the mineral resources. This work analyzed the Sr isotope geochemical characteristics of evaporites from core samples in the well MZK-3 in order to further clarify the material source and to explore the potash distribution in the Simao Basin.展开更多
One main feature of the tectono-paleogeographic evolution of the southern branch of the Paleo-Asian Ocean was that there developed residual marine basins in former backarc/forearc regions after the disappearance of oc...One main feature of the tectono-paleogeographic evolution of the southern branch of the Paleo-Asian Ocean was that there developed residual marine basins in former backarc/forearc regions after the disappearance of oceanic crust.The paper illustrates the viewpoint taking the evolution of Dalandzadgad and Solonker oceanic basins as examples.The Dalandzadgad ocean subducted southwards during the Silurian-Devonian,created an intra-oceanic arc and a backarc basin in southern Mongolia.In addition,a continent marginal arc formed along the national boundary between China and Mongolia,the south of which was a backarc basin.The oceanic basin closed and arc-arc(continent) collision occurred during the early Early Permian,followed by two residual marine basins developing in the former backarc regions,named the South Gobi Basin in southern Mongolia and the Guaizihu Basin in western Inner Mongolia.The Solonker ocean subducted southwards and finally disappeared during the early Middle Permian.Afterwards,two residual marine basins occurred in northern China,the Zhesi Basin being situated in the former backarc region and the Wujiatun Basin in the former forearc region.The late Middle Permian was the most optimum period for the developing residual marine basins,when they covered a vast area.The basin evolution differentiated during the early Late Permian,with a general trend of uplift in the east and of subsidence in the west.The Upper Permian in the South Gobi Basin was characterized by coal-bearing strata hosting economically valuable coal fields.A transgression invaded westwards and the Chandmani-Bayanleg Basin was created in southwest Mongolia during the middle-late stage of the Late Permian.Correspondingly,the coal formation entered a flourishing time,with thick coal beds and sedimentary interbeds.All of these basins,namely,both the marine and nonmarine residual basins,reversed and closed by the end of Permian.展开更多
基金supported by the"national Key R&D Program of China"(grant No.2017YFC0602801)geological survey project of"Investigation and Evaluation of the Potash Deposit Prospect in West China"(grant No.DD20160054)
文摘Objective The Mengyejing potash deposit in the Simao Basin is the only producing area of solid potash at present in China. There is still controversy about the material source and distribution of the potash in this deposit （Shen Lijian et al., 2017）, which has influenced not only the prospecting direction and efficiency but also the understanding of the control of Tethys tectonic evolution on the formation and distribution of the mineral resources. This work analyzed the Sr isotope geochemical characteristics of evaporites from core samples in the well MZK-3 in order to further clarify the material source and to explore the potash distribution in the Simao Basin.
文摘One main feature of the tectono-paleogeographic evolution of the southern branch of the Paleo-Asian Ocean was that there developed residual marine basins in former backarc/forearc regions after the disappearance of oceanic crust.The paper illustrates the viewpoint taking the evolution of Dalandzadgad and Solonker oceanic basins as examples.The Dalandzadgad ocean subducted southwards during the Silurian-Devonian,created an intra-oceanic arc and a backarc basin in southern Mongolia.In addition,a continent marginal arc formed along the national boundary between China and Mongolia,the south of which was a backarc basin.The oceanic basin closed and arc-arc(continent) collision occurred during the early Early Permian,followed by two residual marine basins developing in the former backarc regions,named the South Gobi Basin in southern Mongolia and the Guaizihu Basin in western Inner Mongolia.The Solonker ocean subducted southwards and finally disappeared during the early Middle Permian.Afterwards,two residual marine basins occurred in northern China,the Zhesi Basin being situated in the former backarc region and the Wujiatun Basin in the former forearc region.The late Middle Permian was the most optimum period for the developing residual marine basins,when they covered a vast area.The basin evolution differentiated during the early Late Permian,with a general trend of uplift in the east and of subsidence in the west.The Upper Permian in the South Gobi Basin was characterized by coal-bearing strata hosting economically valuable coal fields.A transgression invaded westwards and the Chandmani-Bayanleg Basin was created in southwest Mongolia during the middle-late stage of the Late Permian.Correspondingly,the coal formation entered a flourishing time,with thick coal beds and sedimentary interbeds.All of these basins,namely,both the marine and nonmarine residual basins,reversed and closed by the end of Permian.
