地球学报2025，Vol.46Issue(3)：533-543,11.DOI:10.3975/cagsb.2024.092402
北羌塘坳陷长蛇山地区夏里组细粒沉积岩形成环境及其对有机质富集的控制作用
The Formation Environment of Fine-grained Sedimentary Rocks and Its Controlling Effect on Organic Matter Enrichment in the Xiali Formation in Changsheshan Area,Northern Qiangtang Depression
摘要
Abstract
The Qiangtang Basin is a Mesozoic Marine hydrocarbon sedimentary basin in China,where the main source rocks have not been definitively confirmed.We herein describe the elemental geochemistry of fine-grained sedimentary rocks of the Xiali Formation in Changsheshan area of Northern Qiangtang depression.Our research indicates that the source rocks of the Xiali Formation in Northern Qiangtang Depression have experienced hot,arid conditions and strong chemical weathering during the sedimentary periods.The sedimentary water was shallow,salty,and oxygen-poor to anoxic,with a moderate sedimentation rate and terrigenous input.The Changsheshan area of the Northern Qiangtang Depression is adjacent to the provenance denudation area in the west of the central uplift,which contains more terrigenous inputs and frequent submarine volcanic activities.The high primary productivity of the upper ocean caused by terrigenous inputs and the phosphorus and iron nutrients content carried by the submarine hydrothermal fluid entering the ocean is the main factor contributing to organic matter enrichment.High paleoproductivity in the Changsheshan area of Northern Qiangtang Depression is the main factor influencing organic matter enrichment.The anoxic sedimentary environment and moderate terrigenous input are also the important conditions for organic matter enrichment.These findings and insights provide a reference for understanding the formation mechanism and predicting the distribution of high-quality source rocks from the Mid-Jurassic sedimentary sequence in Northern Qiangtang depression.关键词
北羌塘坳陷/长蛇山地区/夏里组/有机质富集控制因素Key words
Northern Qiangtang depression/Changsheshan area/Xiali Formation/factors controlling organic matter enrichment分类
地质学引用本文复制引用
陈程,吴珍汉,王利,季长军,赵珍..北羌塘坳陷长蛇山地区夏里组细粒沉积岩形成环境及其对有机质富集的控制作用[J].地球学报,2025,46(3):533-543,11.基金项目
本文由国家自然科学基金项目(编号:42102201)和中国地质调查局地质调查项目(编号:DD20242200)联合资助. This study was supported by National Natural Science Foundation of China(No.42102201),and China Geological Survey(No.DD20242200). （编号:42102201）
