DOI: 10.1016/j.epsl.2017.12.001
Scopus记录号: 2-s2.0-85037690974
论文题名: Cyclostratigraphic constraints on the duration of the Datangpo Formation and the onset age of the Nantuo (Marinoan) glaciation in South China
作者: Bao X. ; Zhang S. ; Jiang G. ; Wu H. ; Li H. ; Wang X. ; An Z. ; Yang T.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 483 起始页码: 52
结束页码: 63
语种: 英语
英文关键词: Cryogenian
; Datangpo Formation
; Milankovitch cycles
; Nantuo Formation
; Snowball Earth
; South China
Scopus关键词: Earth (planet)
; Magnetic susceptibility
; Cryogenian
; Datangpo Formation
; Milankovitch cycle
; Nantuo Formation
; Snowball Earth
; South China
; Glacial geology
; age determination
; cyclostratigraphy
; deep water
; glacial erosion
; glaciation
; magnetic susceptibility
; radiometric method
; uranium-lead dating
; China
; Namibia
英文摘要: Constructing an accurate timeline is critical for reconstructing the Earth systems through critical transitions in climate, geochemistry, and life. Existing dates constrain synchronous initiation (ca. 717 Ma) and termination (ca. 660 Ma) of the Sturtian glaciation from multiple continents. The termination of the younger Marinoan glaciation is also well dated at ca. 635 Ma, but the onset of this glaciation is only roughly constrained as ≤ ca. 654 Ma (South China) and ≥ ca. 639 Ma (Namibia). To test if the Marinoan glaciation started close to ca. 654 Ma or ca. 639 Ma, we have conducted a cyclostratigraphic study on the Cryogenian non-glacial Datangpo Formation that conformably overlies and underlies Sturtian and Marinoan glacial diamictites, respectively, in a deep-water basin section in South China. A total of 28,765 magnetic susceptibility (MS) measurements from a drillcore of the 292-m-thick, muddy siltstone- and shale-dominated Datangpo Formation are used for cyclostratigraphic analysis. The results reveal significant decameter- to meter-scale sedimentary cycles of 16–12 m, 3.6–3.0 m, 1.0–0.8 m, and 0.6–0.4 m. The ratios of these cycle wavelengths match well with those of the Milankovitch cycles calibrated for the Cryogenian Period. The established astrochronologic time scale suggests that the duration of the Datangpo Formation is about 9.8 million years. Together with the radiometric age of ca. 660 Ma for the termination of the Sturtian glaciation, the cyclostratigraphic data suggest that the Nantuo (Marinoan) glaciation in South China initiated at ca. 650 Ma, which is slightly younger than but consistent with the ca. 654 Ma U–Pb age from the top of the Datangpo Formation in shelf sections. This age, however, is significantly older than the ages obtained from Marinoan-age glacial diamictites in South China (ca. 636 Ma) and Namibia (ca. 639 Ma). Given that most of the shelf sections may have suffered from glacial erosion, obtaining the onset age of the Marinoan glaciation should focus on relatively complete, deep-water successions. © 2017
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110087
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China; Department of Geoscience, University of Nevada, Las Vegas, NV 89154-4010, United States; 103 Geological Team, Guizhou Bureau of Geology and Mineral Resources, Tongren, Guizhou 554300, China
Recommended Citation:
Bao X.,Zhang S.,Jiang G.,et al. Cyclostratigraphic constraints on the duration of the Datangpo Formation and the onset age of the Nantuo (Marinoan) glaciation in South China[J]. Earth and Planetary Science Letters,2018-01-01,483