地球学报2025，Vol.46Issue(3)：577-586,10.DOI:10.3975/cagsb.2025.041121
伦北盆地古近系牛堡组页岩地球化学特征及地质意义
Geochemical Characteristics and Significance of Paleogene Niubao Formation Shales in the Lunbei Basin
摘要
Abstract
The structural evolution and hydrocarbon potential of the Lunbei Basin in the northern Tibetan Plateau remain poorly understood,and systematic oil and gas exploration has yet to be conducted.To assess the suitability of the Lunbei Basin for petroleum exploration,this study conducted geochemical analyses on outcrop samples from the Paleogene Niubao Formation.Analyses of total organic carbon content,rock pyrolysis,and gas chromatography indicate that the Niubao Formation shale comprises high-quality source rocks.The organic matter is predominantly a mixture of Type Ⅱ and Type Ⅲ,deposited in a reducing lacustrine environment.Variations in water salinity during deposition led to source rock heterogeneity,while the geochemical characteristics of petroleum remained largely similar.The entire Niubao Formation shale is in the mature stage and has significant oil-generating potential.The source rock for the Niubao Formation oil sands is shale from the same stratigraphic horizon.Thermal anomalies from volcanic tuff formation result in elevated PAH ratios between shale and oil sands.Based on thermal maturity parameters and PAH ratios,the samples are classified into two groups:Class Ⅰ,which is unaffected by thermal anomalies from tuff formation,and Class Ⅱ,which is significantly affected.A comprehensive analysis indicates that thermal anomalies from volcanism accelerate hydrocarbon generation in source rocks.关键词
伦北盆地/页岩/生物标志物/成熟度/油源对比Key words
Lunbei Basin/shale/biomarkers/maturity/oil-source correlation分类
地质学引用本文复制引用
陈冲,申怀明,陈云,季长军..伦北盆地古近系牛堡组页岩地球化学特征及地质意义[J].地球学报,2025,46(3):577-586,10.基金项目
本文由西藏自治区科技计划项目(编号:XZ202401YD0006 （）
XZ202403ZY0040)、深地国家科技重大专项(编号:2024ZD1001005)、国家自然科学基金委项目(编号:U24A20597)和西藏自然资源厅矿产资源勘查专项项目(编号:GZFCG2024-20492)联合资助. This study was supported by Science and Tech-nology Plan Project of the Tibet(Nos.XZ202401YD0006 and XZ202403ZY0040),National Science and Technology Major Project(No.2024ZD1001005),National Natural Science Founda-tion of China(No.U24A20597),and Special Project for Mineral Resources Exploration of the Department of Natural Resources of Tibet(No.GZFCG2024-20492). （编号:2024ZD1001005）
