DOI: 10.1016/j.marpetgeo.2019.104060
论文题名: Palaeoenvironmental periodisms of middle Eocene terrestrial sediments in Bohai Bay Basin, eastern China, and their implications for organic matter accumulation
作者: Chen D. ; Pang X. ; Wang Y. ; Dong Y. ; Jiang F. ; Li L. ; Pang H. ; Bai H. ; Pang B. ; Qin R. ; Jiang H.
刊名: Marine and Petroleum Geology
ISSN: 2648172
出版年: 2020
卷: 112 语种: 英语
英文关键词: Mid-latitude region
; Middle Eocene
; Milankovitch cycles
; Palaeoenvironmental evolution
; Terrestrial shale
Scopus关键词: Biogeochemistry
; Climate change
; Greenhouses
; Hydrocarbons
; Sedimentology
; Spectrum analysis
; Global climate changes
; Hydrocarbon source rocks
; Middle Eocene
; Midlatitudes
; Milankovitch cycle
; Palaeoenvironmental evolution
; Primary productivity
; Terrestrial sediments
; Shale
; Eocene
; geochemical method
; midlatitude environment
; Milankovitch cycle
; mineralogy
; organic matter
; paleoenvironment
; shale
; spectral analysis
; terrestrial deposit
; Bohai Sea
; Bohaiwan Basin
; China
; Nanpu Sag
英文摘要: The middle Eocene was a key period of global climate change from a warm “greenhouse” to a cooling “doubthouse”. At the middle Eocene, an extensive arid climate in China was recorded in the mudstones and shales interbedded with salinastone which formed good hydrocarbon source rocks, especially in the Bohai Bay Basin. The sedimentary paleoenvironment and its variations affected the source rock quality and distribution. Based on successive and dense sampling of the middle Eocene Shahejie Formation shale (MES shale) in Nanpu Sag of Bohai Bay Basin, petro-mineralogical tests, geochemical methods and spectrum analysis were performed to analyse the palaeoenvironmental fluctuations and the responses to Milankovitch cycles. Element analysis on MES shale shows that the middle Eocene climate was arid and the sediments were deposited under dysoxic/suboxic conditions with relatively high salinity. Based on the Δlog R method, the organic matter (OM) abundance was evaluated and ranged from 0.18 to 3.55 wt % for MES shale. The mean primary productivity of 545 g C m−2 yr−1 shows a eutrophic environment in middle Eocene Nanpu paleolake. Wavelet analysis performed on gamma logging and palaeoenvironmental proxies revealed clear Milankovitch cycles for MES shale, and the cyclostratigraphic and palaeoenvironmental fluctuations were effected by astronomical oscillation periods of the short eccentricity cycle (100 k.y.), obliquity cycle (39 k.y.) and precession cycle (19 k.y.). The depositional rate of MES shale was corrected to 0.43 m/k.y. The sedimental process of MES shale was associated with palaeoenvironmental variation, which have been divided into four stages affecting OM accumulation. A hypothesis that the vast carbon of “greenhouse” gases in the Palaeocene and early Eocene was fixed in organic matters during middle Eocene and enriched in the hydrocarbon source rocks of the sedimentary basins formed at early Eocene was proposed to explain the “doubthouse” world in the Eocene. © 2019 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/159550
Appears in Collections: 气候变化与战略
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作者单位: State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing, 102249, China; College of Geosciences, China University of Petroleum (Beijing), Beijing, 102249, China; Department of Geosciences and Engineering, Delft University of Technology, Stevinweg 1, Delft, 2628 CN, Netherlands; PetroChina Jidong Oilfield Company, Tangshan, 063004, China; China ZhenHuaOil Co.,Ltd., Beijing, 100031, China; Strategic Research Center of Oil and Gas Resources, MNR, China
Recommended Citation:
Chen D.,Pang X.,Wang Y.,et al. Palaeoenvironmental periodisms of middle Eocene terrestrial sediments in Bohai Bay Basin, eastern China, and their implications for organic matter accumulation[J]. Marine and Petroleum Geology,2020-01-01,112