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滇中盆地石炭纪—中二叠世沉积-古地理特征与富Li黏土岩物源分析
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作者 张佳慧 闫臻 +6 位作者 薛传东 俞良军 魏爱英 付长垒 王维 王宇 周红琳 《地质学报》 北大核心 2025年第4期1120-1133,共14页
滇中盆地石炭系—中二叠统产有铝土矿、煤、方解石矿、石灰岩等矿产,并伴生大量的富Li黏土岩,其成矿环境受沉积环境及其构造古地理时空演变的制约。系统的野外调查研究显示,滇中盆地石炭系是一套形成于滨岸潮坪-潟湖环境的陆源碎屑岩和... 滇中盆地石炭系—中二叠统产有铝土矿、煤、方解石矿、石灰岩等矿产,并伴生大量的富Li黏土岩,其成矿环境受沉积环境及其构造古地理时空演变的制约。系统的野外调查研究显示,滇中盆地石炭系是一套形成于滨岸潮坪-潟湖环境的陆源碎屑岩和碳酸盐岩组合,下—中二叠统则为潟湖-潮坪-开阔台地相沉积组合。其中,下石炭统大塘组主体表现为潮坪环境的碳酸盐岩夹泥页岩组合,潟湖相沉积仅出现在牛首山古陆周缘;上石炭统威宁组和马平组仅在牛首山古陆旁侧零星出露,为滨岸潮坪相沉积;下二叠统倒石头组是一套细粒陆源碎屑沉积组合,局部夹少量灰岩透镜体,产有铝土矿、煤矿及富Li黏土岩,形成于潮坪-潟湖环境;中二叠统栖霞组和茅口组为藻屑灰岩、白云质亮晶生屑灰岩及中—粗晶白云岩组合,为开阔台地相沉积。空间上,大塘组和倒石头组厚度变化较大,总体具有向南地层厚度变薄且煤层和铝土质岩层数减少的趋势,显示水体向南逐渐变浅;栖霞组和茅口组向北的出露面积和厚度增大,与古水流分析揭示的早、中二叠世滇中地区具有东南高、西北低的古地貌特征相一致。这说明,滇中盆地东南侧的牛首山古隆起是该盆地倒石头组的主要沉积物供给区。岩石地球化学资料显示,倒石头组为富Al和Li的黏土岩,并受物源区风化强度和沉积环境的控制,当Al_(2)O_(3)<55%、Al_(2)O_(3)/SiO_(2)<3时,Li与Al_(2)O_(3)含量呈正相关关系,其余均呈负相关关系。区域资料分析显示,牛首山古隆起以前寒武纪中—基性火山岩和相关沉积岩为主,在早石炭世—中二叠世受古特提斯洋持续打开的影响发生区域隆升,导致其火山-沉积地层发生风化剥蚀并伴随区域火山活动,从而成为其旁侧的滇中盆地铝土矿和富Li黏土岩的重要来源。 展开更多
关键词 石炭纪—中二叠世 沉积-古地理环境 物源分析 富Li黏土岩 牛首山 滇中盆地
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Neoproterozoic stratigraphic correlation of Subei-Huainan in China 被引量:1
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作者 刘为付 刘双龙 +3 位作者 孙立新 白文爽 丁振坤 王泽宇 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第6期1449-1458,共10页
Subei-Huainan in the southeastern margin of the North China platform is a key area of convergence of China’s north-south stratigraphic correlation of Neoproterozoic.Due to the lack of fossils,the Neoproterozoic strat... Subei-Huainan in the southeastern margin of the North China platform is a key area of convergence of China’s north-south stratigraphic correlation of Neoproterozoic.Due to the lack of fossils,the Neoproterozoic stratigraphic correlation is still a difficulty in this area.The division of Neoproterozoic strata and the establishment of the correlation framework of the stratigraphic sequences have been done through recognizing the regularity of meter-scale cycles by measuring the outcrop of Neoproterozoic strata and using the Fischer diagram and the sea-level curve of transgressive-regressive by the maximum flooding sedimentary and molar teeth carbonate sedimentary.The maximum flooding sedimentary which becomes cycle sequence comparison of sign is isochronous in the same basin and is a key of cycle sequence comparison although paleogeographic environment and sedimentary sequence may be different in the sedimentary strata of the same geologic time.Molars carbonates,having specific geological distrution time and depositional environment and mainly developing in the ramp environment of the platform edge in the 1500-650 Ma,are the new symbol of the stratigraphic correlation in the Neoproterozoic.Because of the missing of the fossil record,the maximum flooding and the molar-teeth carbonate sedimentary,as the new research ideas,are used in stratigraphic division and correlation. 展开更多
关键词 Fischer diagram sea-level change molar-teeth carbonate maximum flooding sedimentary NEOPROTEROZOIC Subei-Huainan
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