摘要
鄂尔多斯盆地西缘石炭系羊虎沟组的烃源岩条件好,但其沉积环境存在较大的争议,因盆地中部、南部的羊虎沟组露头的部分层位存在缺失,以北部地区乌达剖面为例开展了系统研究。采用便携式X射线荧光光谱仪对剖面进行连续精确测试,结合孢粉古生物、干酪根-δ^(13)C‰、稀土元素分析,对工区的古氧化还原环境、古气候、古水深及体系域进行分析。结果表明:通过V/(V+Ni)、Ni/Co、δEu值判别羊虎沟时期处于氧化到还原的过渡阶段;Sr/Cu介于1.3~7.8,蕨类植物孢子占绝对优势地位,处于温暖潮湿气候;羊虎沟时期从低水位体系域到海侵体系域再到高位体系域,Al元素的质量分数和Sr/Ba值由高→低→高,而Mg元素的质量分数由低→高→低。该区域主要受西北部阿拉善古陆物源控制,总体表现为滨浅海-三角洲复合沉积环境。
The source rock condition of the Carboniferous Yanghugou Formation in the western margin of Ordos Basin is good,but its sedimentary environment is controversial.Due to the lack of some outcrops of the Yanghugou Formation in the central and southern parts of the basin,the Wuda section in the northern area was taken as an example to carry out a systematic study.A portable X-ray fluorescence spectrometer was used for continuous and accurate testing of the profile.Combined with sporopollenin paleontology,kerogen-δ^(13)C‰,and rare earth element analysis,the paleoredox environment,paleoclimate,paleowater depth,and system tract of the work area were analyzed.The results show these as follows.By V/(V+Ni),Ni/Co,δEu values,the Yanghugou period is in the transition stage from oxidation to reduction.Sr/Cu is between 1.3~7.8,pteridophyte spores are dominant,the Yanghugou period is in warm and humid climate.From lowstand system tract to transgressive system tract and then to highstand system tract,Al content and Sr/Ba value increase from high to low,the mass fraction of Mg changes from low to high.This area is mainly controlled by the provenance of Alashan paleocontinent in the northwest and is generally characterized by the composite sedimentary environment of coastal shallow sea delta.
作者
司锦
胡勇
侯云东
孙继峰
何文祥
陆雨诗
SI Jin;HU Yong;HOU Yun-dong;SUN Ji-feng;HE Wen-xiang;LU Yu-shi(Hubei Key Laboratory of Petroleum Geochemistry and Environment, Yangtze University, Wuhan 430100, China;Key Laboratory of Exploration Technologies for Oil and Gas Resources,Yangtze University, Ministry of Education, Wuhan 430100, China;Development, Changqing Oilfield Company of PetroChina, Xi'an 710000, China)
出处
《科学技术与工程》
北大核心
2021年第27期11514-11526,共13页
Science Technology and Engineering
基金
国家自然科学基金(41872144)
国家科技重大专项(2016ZX05046-002,2016ZX05047-005)。
关键词
鄂尔多斯盆地西缘北段
便携式X射线荧光光谱仪
古环境
羊虎沟组
the northern part of the western margin of Ordos Basin
portable X-ray fluorescence spectrum
paleoenvironmental
the Yanghugou Formation
