Sedimentary Environment of Ediacaran Sequences of South China: Trace Element and Sr-Nd Isotope Constraints
| Autor: | Wei Wang, Rong Hu, Fukun Chen, Yi-Zeng Yang, Shuang-Qing Li |
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| Rok vydání: | 2016 |
| Předmět: |
Provenance
010504 meteorology & atmospheric sciences Rare-earth element Geochemistry Trace element Geology 010502 geochemistry & geophysics 01 natural sciences Seafloor spreading Doushantuo Formation Sedimentary depositional environment Paleontology Paleoclimatology Sedimentary rock 0105 earth and related environmental sciences |
| Zdroj: | The Journal of Geology. 124:769-789 |
| ISSN: | 1537-5269 0022-1376 |
| Popis: | Post-Marinoan sedimentary rocks from the Yangtze block in South China were investigated to seek constraints on their provenance, genetic relationship with paleoclimate, depositional environment, and changes. Sedimentary rocks from the Doushantuo Formation in the Jiulongwan section of the Yangtze block were collected for whole-rock trace elements and Sr-Nd isotopic analyses. Flat-to-slightly middle rare earth element (REE)–enriched REE-plus-yttrium patterns, negative-to-positive Ce anomalies (Ce/Ce* of 0.86–1.40), positive La anomalies (La/La* of 1.02–1.42), and suprachondritic Y/Ho ratios (36.8–49.5) obtained for the Doushantuo cap carbonates indicate their deposition in a fluctuating inner-shelf setting where freshwater and seawater mixed together and the influence of hydrothermal fluid from the seafloor is absent. All Doushantuo carbonates and shales have variable Sr isotopic compositions, with initial Sr isotopic ratios (0.704030–0.712720) that support significant river-water contribution durin... |
| Databáze: | OpenAIRE |
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