Paleoenvironmental Evolution and Organic Matter Enrichment Genesis of the Late Turonian Black Shale in the Southern Songliao Basin,NE China  

作　　者：BAI Jing XU Xingyou LIU Weibin ZHAO Wenzhi JIANG Hang 

机构地区：[1]State Key Laboratory of Continental Shale Oil,Beijing 100029,China [2]Key Laboratory of Unconventional Oil and Gas,China Geological Survey,Beijing 100029,China [3]Oil and Gas Survey,China Geological Survey,Beijing 100029,China [4]Research Institute of Petroleum Exploration Development of PetroChina,Beijing 100083,China [5]Strategic Research Center of Oil and Gas Resources,Ministry of Natural Resources,Beijing 100860,China

出　　处：《Acta Geologica Sinica(English Edition)》2024年第5期1338-1358,共21页地质学报（英文版）

基　　金：funded by a grant from the National Natural Science Foundation of China(Grant Nos.U2244207,42102200);the China Geological Survey Foundation(Grant Nos.DD20230257,DD20242404)。

摘　　要：The Upper Cretaceous Qingshankou Formation black shales,deposited in the late Turonian(LTB shales),are the main source rocks of the Songliao Basin.The origins of organic matter enrichment of the shales is a contentious subject fuelling many ongoing debates.This study investigates the genesis of the organic matter-rich shale by using molecular geochemistry.The LTB shales can be divided into three sections.The SectionⅠshales were deposited in saline,stratified and anoxic water conditions,which are related to seawater incursion events.At least three episodic and periodic seawater incursion events were recognized during SectionⅠshale deposition.The SectionⅡshales deposited in brackish to fresh and deep lake-level conditions with high primary productivity,which are related to lake-level transgression.The SectionⅢshales were deposited under fresh and slightly oxidized water conditions,which are related to lake-level regression.Two organic matter enrichment models for the LTB shales are identified,that is,the seawater incursion model and the maximum lake-level transgression sedimentation model,which act on different shale sections,both playing significant roles in the enrichment of organic matter.

关 键 词：organic matter-rich shale paleoenvironmental evolution enrichment genetics late Turonian CRETACEOUS Songliao Basin 

分 类 号：P618.13[天文地球—矿床学]