山西地堑系太原盆地晚新生代沉积环境演化及物源分析  

Late Cenozoic Sedimentary Environment Evolution and Provenance Analysis of Taiyuan Basin in Shanxi Graben System

作　　者：庄其天 何宏林[1,2] 魏荣珠[3] 王忠梅 石峰[1,2] 闫纪元 ZHUANG QiTian;HE HongLin;WEI RongZhu;WANG ZhongMei;SHI Feng;YAN JiYuan(State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration,Beijing 100029,China;Shanxi Taiyuan Continental Rift Dynamics National Observation and Research Station,Beijing 100029,China;Shanxi Institute of Geological Survey,Taiyuan 030006,China;Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China)

机构地区：[1]中国地震局地质研究所,地震动力学国家重点实验室,北京100029 [2]山西太原大陆裂谷动力学国家野外科学观测研究站,北京100029 [3]山西省地质调查院,太原030006 [4]中国地质科学院地质力学研究所,北京100081

出　　处：《沉积学报》2024年第2期486-501,共16页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(41872213,U1939201,41702221,41602206);中国地质科学院地质研究所项目(121201102000150012-05);山西省国土资源厅地勘基金项目(HXCT01-2018F005);山西太原大陆裂谷动力学国家野外科学观测研究站项目(NORSTY20-04)。

摘　　要：【目的】山西地堑系因其独特的大地构造位置成为研究中国东部晚新生代变形的热点地区,然而受露头剖面的局限,目前少有报道地堑系盆地完整的沉积环境演化的工作,对进一步认识地堑系演化过程造成了困难。【方法】通过太原盆地ZK01钻孔揭露的约8.1 Ma以来的详细沉积记录,开展了沉积环境和物源分析工作。【结果和结论】沉积环境分析表明太原盆地经历了河流—三角洲/湖泊—河流的沉积环境演化过程,其中分别在5.8~4.4 Ma和2.2~1.6 Ma发育两期覆盖整个太原盆地的湖泊。物源分析表明在5.8 Ma前后存在物源转变。5.8 Ma以前物源主要来自东部太行山脉的侏罗系石英砂岩;5.8 Ma以后物源转为以三叠系长石砂岩为主,同时吕梁山北部的变质岩和火山岩碎屑进入盆地,表明汾河开始流入太原盆地。太原盆地沉积环境演化与区域古气候和构造的关系,表明盆地的湖泊扩展过程主要受构造沉降控制,是青藏高原东向扩展作用的构造—地貌响应。[Objective]The Shanxi Graben System has become an important area of Late Cenozoic deformation research in eastern China for its unique tectonic location.However,due to the limitations of the outcrop profile,complete sedimentary environment evolution of the basins in the graben system is rarely reported,which hinders our understanding of its evolution process.[Methods]The depositional environments and provenance were analyzed using the detailed sedimentary record from the ZK01 borehole in the Taiyuan Basin.[Results and Conclusions]The analysis of the sedimentary environment shows that the Taiyuan Basin underwent a fluvialdelta/lakeriver sedimentary environment evolution process.Two mega transgressions generated basin-wide lakes,one at ca.5.84.4 and the other at ca.2.21.6 Ma.Provenance analysis shows that the provenance was mainly theJurassic quartz sandstones of the Taihang Mountain before 5.8 Ma.After 5.8 Ma,the provenance changed to the Triassic feldspathic sandstones,Meanwhile,the debris of metamorphic and volcanic rocks from the northern part of the Lvliang Mountain began to enter the basin,indicating the development of Fen River in the Taiyuan Basin.Asynchronous processes between paleoclimatic variations and transgressions illustrate the lakes’spreading processes as mainly influenced by tectonic subsidence,being a structural-geomorphic response to the eastward spreading of the Qinghai-Tibetan Plateau.

关 键 词：山西地堑系 太原盆地 沉积环境 物源分析 古气候 

分 类 号：P512.2[天文地球—地质学]