地质通报2026，Vol.45Issue(4)：657-677,21.DOI:10.12097/gbc.2024.04.036
大洋缺氧事件的陆相古环境与资源效应:松辽盆地晚白垩世页岩油层地球化学特征分析
Terrestrial paleoenvironment and related resources during Oceanic Anoxic Events:Geochemical analysis of Late Cretaceous shale oil strata in the Songliao Basin
摘要
Abstract
[Objective]The SYY1 well is the first borehole to achieve industrial production of matrix-type shale oil from the thick shale and mudstone of the 1st Member of the Qingshankou Formation(Qing-1 Member)in the Songliao Basin.[Methods]Through geochemical analysis and stratigraphic oil and gas-bearing testing,this paper explores the paleoenvironment and shale oil resource potential of the black shale and mudstone formed in the lacustrine basin of Northeast China during the Oceanic Anoxic Event 2(OAE2).[Results]The paleoclimatic indicator CaO/(MgO×Al2O3)ranges from 0.01 to 1.29(average 0.10).The redox coefficient(K)predominantly falls between 0.11 and 0.64(average 0.38),while other redox proxies(δU,V/Sc and V/(V+Ni))yield mean values of 1.17,8.23,and 0.80,respectively.Paleosalinity indicators show mean values of 57.9×10-6 for B,2.5 for B/Ga,0.7 for Sr/Ba,and 2.2 for Th/U.The δ18O values range from-17.50‰ to-15.58‰,and δ13C values vary between 0.26‰ and 2.00‰.[Conclusions]The analysis of geochemical characteristics and environmental indicators suggests that the black shale and mudstone of the Qing-1 Member were formed in a warm,humid lacustrine environment with freshwater to slightly brackish conditions(occasionally influenced by seawater),within a reducing(anaerobic)environment.These conditions reflect the sedimentary response to OAE2 in terrestrial lacustrine anoxic event(LAE).Additionally,the thick,dark shale and mudstone in the Qing-1 Member have high total organic carbon(TOC)content,with a positive correlation between biologically beneficial elements such as phosphorus(P)and copper(Cu)and TOC,revealing extremely high productivity in the ancient lake basin.This provides a rich material basis for the Qing-1 Member in the Songliao Basin.Moreover,stratigraphic hydrocarbon testing has confirmed that TOC is one of the main controlling factors for shale oil accumulation in lacustrine environments.The matrix-type shale oil reservoirs exhibit significant potential,indicating abundant shale oil resources in the Qingshankou Formation of the Songliao Basin.关键词
松辽盆地/晚白垩世/大洋缺氧事件/古环境/地球化学特征/页岩油Key words
Songliao Basin/Late Cretaceous/oceanic anoxic event/palaeoenvironment/geochemistry characteristics/shale oil分类
天文与地球科学引用本文复制引用
张德军,王广,陈树旺,孙雷,公樊浩,卞雄飞,孙守亮,张海华,沈斌,徐学敏..大洋缺氧事件的陆相古环境与资源效应:松辽盆地晚白垩世页岩油层地球化学特征分析[J].地质通报,2026,45(4):657-677,21.基金项目
中国地质调查局项目《东北地区地层古生物地质调查》(编号:DD20230220)和国家自然科学基金项目《古生代—中生代重大转折期极端气候与生物响应》(批准号:42293280)、《大兴安岭中南部中侏罗世植物群及地层新探》(批准号:42172024)、《黑龙江嘉荫盆地晚白垩世中—晚期植物群演替及其古环境背景》(批准号:42172017),国家重点研发计划课题《白垩纪中期松辽盆地及邻区陆相储集层与烃源岩研究》(编号:2019YFC0605404) Supported by the project of China Geological Survey(No.DD20230220),National Natural Science Foundation of China(Nos.42293280,42172024,42172017)and National Key R&D Program of China(No.2019YFC0605404) （编号:DD20230220）
