气候变化领域集成服务门户(CCPortal): Anomalous marine calcium cycle linked to carbonate factory change after the Smithian Thermal Maximum (Early Triassic)

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DOI	10.1016/j.earscirev.2020.103418
	Anomalous marine calcium cycle linked to carbonate factory change after the Smithian Thermal Maximum (Early Triassic)
	Zhao H.; Dahl T.W.; Chen Z.-Q.; Algeo T.J.; Zhang L.; Liu Y.; Hu Z.; Hu Z.
发表日期	2020
ISSN	00128252
卷号	211
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
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
语种	英语
来源期刊	Earth Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203956
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
推荐引用方式 GB/T 7714	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],2020,211.
APA	Zhao H..,Dahl T.W..,Chen Z.-Q..,Algeo T.J..,Zhang L..,...&Hu Z..(2020).Anomalous marine calcium cycle linked to carbonate factory change after the Smithian Thermal Maximum (Early Triassic).Earth Science Reviews,211.
MLA	Zhao H.,et al."Anomalous marine calcium cycle linked to carbonate factory change after the Smithian Thermal Maximum (Early Triassic)".Earth Science Reviews 211(2020).