气候变化领域集成服务门户(CCPortal): Geochemical characteristics and depositional paleoenvironment of source rocks from the Lower Cretaceous Chijinbao Formation in Jiuxi Basin, China

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DOI	10.1016/j.petrol.2021.109968
	Geochemical characteristics and depositional paleoenvironment of source rocks from the Lower Cretaceous Chijinbao Formation in Jiuxi Basin, China
	Ma, Bo; Ji, Liming; Jin, Peihong; Zhang, Mingzhen; Yuan, Bochao; Long, Liwen
通讯作者	Ji, LM (通讯作者)，382 Donggang Rd, Lanzhou 730000, Gansu, Peoples R China.
发表日期	2022
ISSN	0920-4105
EISSN	1873-4715
卷号	210
英文摘要	The Lower Cretaceous Chijinbao Formation is one of the primary source rocks in the Jiuxi Basin in Northwest China. However, it is poorly studied due to the lack of a complete stratigraphic sequence exposed by drilling. In this research, an integrated analysis of palynofacies, organic geochemistry, and element geochemistry was systematically conducted on samples with longitudinal continuity collected from the Chijinbao Formation in the Hanxia Section of the Jiuxi Basin to determine the distribution of source rocks and the source and type of organic matter and to reconstruct the depositional paleoenvironment of the Chijinbao Formation. The lower part of the sequence, which is governed by poor source rocks with Type III organic matter, is characterized by palynofacies A (woody tissue-charcoal assemblage) grown in a proximal alluvial fan-shallow lacustrine environment. The excellent source rocks with mostly Type II1 organic matter are considerable in the middle part of the sequence, which is marked by palynofacies B (amorphous organic matter assemblage), and occur in a distal semi-deep lacustrine-deep lacustrine environment. The upper part of the sequence is largely composed of poor and fair source rocks, represented by palynofacies C (amorphous organic matter-woody tissue assemblage), and a small amount of sporadically distributed good and excellent source rocks (approximately 1/3), which may be deposited in a proximal fan delta and a local semi-deep lacustrine-deep lacustrine environment. A semiarid-semi-humid climate and a freshwater-brackish water environment prevailed during the deposition of the Chijinbao Formation. The lower part of the sequence is characterized by the highest terrestrial detritus influx, strong weathering, humid paleoclimate, oxic water column conditions, and the lowest paleoproductivity. The middle part of the sequence has the lowest terrestrial detritus influx, relatively weak weathering, relatively arid paleoclimate, predominantly anoxic water environment, and the highest paleoproductivity. The climate became humid again during the deposition of the upper part, which is typified by an intermediate terrestrial detritus influx, strong weathering, fluctuations of oxic-anoxic bottom-water conditions, and moderate paleoproductivity. The correlation analysis of element proxies suggests that the increase in salinity during the deposition of the middle part is associated with an arid climate. Amorphous organic matter, which is derived mostly from aquatic organisms and degraded terrestrial higher plants, is the major hydrocarbon generation component in the source rocks of the Chijinbao Formation. It increases in abundance with an improvement in water reducibility and productivity, favoring the formation and preservation of excellent source rocks.
关键词	TRIASSIC YANCHANG FORMATION ORGANIC-MATTER JIUQUAN BASIN ORDOS BASIN PALEOCLIMATE CONDITIONS ELEMENT GEOCHEMISTRY XIAGOU FORMATION NORTHWEST CHINA QINGXI SAG OIL-SHALE
英文关键词	Source rock; Palynofacies; Element geochemistry; Paleoenvironment; Chijinbao formation; Jiuxi basin
语种	英语
WOS研究方向	Energy & Fuels ; Engineering
WOS类目	Energy & Fuels ; Engineering, Petroleum
WOS记录号	WOS:000731264100001
来源期刊	JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
来源机构	中国科学院西北生态环境资源研究院
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/255016
作者单位	[Ma, Bo; Ji, Liming; Jin, Peihong; Zhang, Mingzhen] Chinese Acad Sci, Northwest Inst Ecoenvironm & Resources, Key Lab Petr Resources, Lanzhou 730000, Gansu, Peoples R China; [Ma, Bo] Univ Chinese Acad Sci, Beijing 100049, Peoples R China; [Ji, Liming; Zhang, Mingzhen] Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Organ Geochem, Guangzhou 510640, Guangdong, Peoples R China; [Yuan, Bochao] PetroChina Yumen Oilfield Co, Res Inst Explorat & Dev, Jiuquan 735019, Gansu, Peoples R China; [Long, Liwen] PetroChina Res Inst Petr Explorat & Dev Northwest, Lanzhou 730020, Gansu, Peoples R China
推荐引用方式 GB/T 7714	Ma, Bo,Ji, Liming,Jin, Peihong,et al. Geochemical characteristics and depositional paleoenvironment of source rocks from the Lower Cretaceous Chijinbao Formation in Jiuxi Basin, China[J]. 中国科学院西北生态环境资源研究院,2022,210.
APA	Ma, Bo,Ji, Liming,Jin, Peihong,Zhang, Mingzhen,Yuan, Bochao,&Long, Liwen.(2022).Geochemical characteristics and depositional paleoenvironment of source rocks from the Lower Cretaceous Chijinbao Formation in Jiuxi Basin, China.JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING,210.
MLA	Ma, Bo,et al."Geochemical characteristics and depositional paleoenvironment of source rocks from the Lower Cretaceous Chijinbao Formation in Jiuxi Basin, China".JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING 210(2022).