山西地堑系太原盆地晚新生代沉积环境演化及物源分析OA北大核心CSTPCD

[Objective]The Shanxi Graben System has become an important area of Late Cenozoic deformation re-search in eastern China for its unique tectonic location.However,due to the limitations of the outcrop profile,com-plete sedimentary environment evolution of the basins in the graben system is rarely reported,which hinders our un-derstanding 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 fluvial-delta/lake-river sedimenta-ry environment evolution process.Two mega transgressions generated basin-wide lakes,one at ca.5.8-4.4 and the other at ca.2.2-1.6 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.