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DOI	10.1016/j.palaeo.2020.110024
	Environmental response to volcanic activity and its effect on organic matter enrichment in the Permian Lucaogou Formation of the Malang Sag; Santanghu Basin; Northwest China
	Pan Y.; Huang Z.; Li T.; Guo X.; Xu X.; Chen X.
发表日期	2020
ISSN	0031-0182
卷号	560
英文摘要	Lacustrine organic-rich fine-grained rocks are widespread in the second member of the Permian Lucaogou Formation (P2l2) in the Malang Sag, Santanghu Basin, with complex lithology and significant changes of lithofacies due to frequent volcanic activity. In this study, the mineralogical and petrological characteristics, types of organic matter (OM), and effect of volcanism on the sedimentary environment and OM accumulation were analyzed using organic, carbon, and oxygen isotopes, as well as major and trace element data. The results revealed that the P2l2 was characterized by mixed deposition of volcanic ash and carbonate minerals, with four main rock types: tuff, dolomitic tuff, tuffaceous dolomite, and dolomite. The fine-grained rocks dominantly contain type I and II1 kerogens, which were in a low-mature stage and exhibited excellent original hydrocarbon generative potential. When volcanic activity was strong, large amounts of nutrients were released by the volcanic ash, which then entered the lake, in turn promoting the blooming of phytoplankton, and causing the δ13C values in the tuff to decrease. In addition, the paleotemperature decreased for a short time, and the suboxic-euxinic environment was conducive to the preservation of OM, resulting in high total organic carbon (TOC) content in the tuff. In contrast, during intermittent or weak periods of volcanic activity, the climate was hotter and drier, and evaporation resulted in a sustained increase of salinity. Consequently, the growth of algae was restricted, which brought about an increase in the δ13C values and relatively low TOC content in the dolomite. The relationships among primary productivity, redox conditions, clastic influx proxies, and TOC content illustrate that primary productivity was the most vital control on the accumulation of OM. High primary productivity was mainly driven by volcanic ash falls. Meanwhile, high salinity and suboxic-euxinic conditions were beneficial to the preservation of OM, giving rise to a high degree of OM enrichment. © 2020 Elsevier B.V.
英文关键词	Fine-grained rocks; Primary productivity; TOC content; Volcanic ash;δ13C value
语种	英语
scopus关键词	carbonate; evaporation; fine grained sediment; growth rate; hydrocarbon; lithofacies; organic matter; paleotemperature; Permian; total organic carbon; volcanic ash; volcanism; China; Santanghu Basin; Xinjiang Uygur; algae
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150299
作者单位	State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijng, 102249, China; College of Geosciences, China University of Petroleum, Beijing, 102249, China; School of Earth Sciences and Engineering, Xi'an Shiyou University, Xi'an, 710065, China; PetroChina Tuha Oilfield Company, Hami, 839009, China
推荐引用方式 GB/T 7714	Pan Y.,Huang Z.,Li T.,et al. Environmental response to volcanic activity and its effect on organic matter enrichment in the Permian Lucaogou Formation of the Malang Sag; Santanghu Basin; Northwest China[J],2020,560.
APA	Pan Y.,Huang Z.,Li T.,Guo X.,Xu X.,&Chen X..(2020).Environmental response to volcanic activity and its effect on organic matter enrichment in the Permian Lucaogou Formation of the Malang Sag; Santanghu Basin; Northwest China.Palaeogeography, Palaeoclimatology, Palaeoecology,560.
MLA	Pan Y.,et al."Environmental response to volcanic activity and its effect on organic matter enrichment in the Permian Lucaogou Formation of the Malang Sag; Santanghu Basin; Northwest China".Palaeogeography, Palaeoclimatology, Palaeoecology 560(2020).