DOI: 10.1016/j.earscirev.2020.103418
论文题名: Anomalous marine calcium cycle linked to carbonate factory change after the Smithian Thermal Maximum (Early Triassic)
作者: Zhao H. ; Dahl T.W. ; Chen Z.-Q. ; Algeo T.J. ; Zhang L. ; Liu Y. ; Hu Z. ; Hu Z.
刊名: Earth Science Reviews
ISSN: 00128252
出版年: 2020
卷: 211 语种: 英语
中文关键词: Calcium cycle
; Calcium isotopes
; Early Triassic
; Olenekian
; South China
; Spathian
英文关键词: anoxic conditions
; calcium
; carbonate sediment
; continental shelf
; depositional environment
; extinction
; marine environment
; Permian
; Triassic
; China
英文摘要: Extreme greenhouse warming in the latest Permian played a key role in the largest animal extinction event ever recorded in Earth history. The extinction was likely triggered by volcanic eruptions that dramatically increased atmospheric CO2 levels and pushed the Earth system into a lethally hot greenhouse state with stratified, anoxic and more acidic oceans. These conditions intensified a few million years later during the middle/late Smithian Thermal Maximum (STM), and a further biodiversity loss occurred during the subsequent cooling across the Smithian-Spathian boundary (SSB). The marine carbonate factory is expected to have changed during this period, but relevant studies are still lacking. Here, we report calcium isotopic data of bulk carbonate rocks (δ44/40Cacarb) from two marine carbonate sections (Jiarong and Shitouzhai) in South China, showing ~0.5–0.7‰ positive shift of δ44/40Cacarb coupled to a ~ 4–6‰ positive shift of δ13Ccarb from the middle Smithian to the early Spathian. Box modeling of the marine Ca cycle yielded two scenarios (i.e., constant and variable δ44/40Caseawater) that can produce a ~0.5‰ positive shift of δ44/40Cacarb: (1) A local mineralogical shift in primary carbonate mineralogy at both sites from 80% aragonite to 80% calcite, or (2) a >10× increase of global carbonate burial flux. The former is consistent with a ~20-50-fold rise of Ca/Mg ratios and ~10-50-fold decrease of Sr/Ca ratios in the study sections, and the latter fits well with massive carbonate deposition globally during the early Spathian. Oceanic overturn and upwelling of alkaline deep waters during SSB climatic cooling is proposed as the main reason for the increase in carbonate burial flux. Thus, the SSB transition marks an important step in the recovery of the marine fauna after the ddd triggered by climatic cooling, ocean ventilation, and a pronounced rise in marine carbonate deposition on continental shelves. © 2020 Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/166325
Appears in Collections: 气候变化与战略
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作者单位: State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, 430074, China; GLOBE Institute, University of Copenhagen, Copenhagen, DK-1350, Denmark; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China; Department of Geology, University of Cincinnati, Cincinnati, OH 45221-0013, United States
Recommended Citation:
Zhao H.,Dahl T.W.,Chen Z.-Q.,et al. Anomalous marine calcium cycle linked to carbonate factory change after the Smithian Thermal Maximum (Early Triassic)[J]. Earth Science Reviews,2020-01-01,211