干旱区生态环境知识资源中心(Arid): Aridity-driven decoupling of delta C-13 between pedogenic carbonate and soil organic matter

Arid

DOI	10.1130/G47241.1
	Aridity-driven decoupling of delta C-13 between pedogenic carbonate and soil organic matter
	Da, Jiawei; Zhang, Yi Ge; Li, Gen; Ji, Junfeng
通讯作者	Ji, JF
来源期刊	GEOLOGY
ISSN	0091-7613
EISSN	1943-2682
出版年	2020
卷号	48 期号:10 页码:981-985
英文摘要	Pedogenic carbonate is an invaluable archive for reconstructing continental paleoclimate and paleoecology. The delta C-13 of pedogenic carbonate (delta C-13(c)) has been widely used to document the rise and expansion of C-4 plants over the Cenozoic. This application requires a fundamental presumption that in soil pores, soil-respired CO2 dominates over atmospheric CO2 during the formation of pedogenic carbonates. However, the decoupling between delta C-13, and delta C-13 of soil organic matter (delta C-13(SOM)) have been observed, particularly in arid regions, suggesting that this presumption is not always valid. To evaluate the influence of atmospheric CO2 on soil delta C-13(c), here we performed systematic delta C-13 analyses of paleosols across the Chinese Loess Plateau, with the sample ages spanning three intervals: the Holocene, the Late Pleistocene, and the mid-Pliocene warm period. Our paired delta C-13(c), and delta C-13(SOM) data reveal broadly divergent trending patterns. Using a two-component Ca-mixing model, we show substantial incorporations of atmospheric CO2 (up to 60%) into soil pore space during carbonate precipitation. This result readily explains the enrichment of delta C-13(c) and its divergence from delta C-13(SOM). As a consequence, delta C-13 of pedogenic carbonates formed under semiarid and/or arid conditions are largely driven by regional aridity through its control on soil CO2 composition, and thus cannot be used to evaluate the relative abundance of C-3 versus C-4 plants. Nonetheless, these carbonates can be applied for atmospheric CO2 reconstructions, even for periods with low CO2 levels.
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000575099900008
WOS关键词	STABLE ISOTOPIC COMPOSITION ; CHINESE LOESS ; C-4 GRASSES ; EAST-ASIA ; MONSOON ; BIOMASS ; VALUES ; PRECIPITATION ; CONSTRAINTS ; EXPANSIONS
WOS类目	Geology
WOS研究方向	Geology
来源机构	南京大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/326629
作者单位	[Da, Jiawei; Ji, Junfeng] Nanjing Univ, Sch Earth Sci & Engn, Key Lab Surficial Geochem, Minist Educ, Nanjing 210023, Peoples R China; [Zhang, Yi Ge] Texas A&M Univ, Dept Oceanog, College Stn, TX 77843 USA; [Li, Gen] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA
推荐引用方式 GB/T 7714	Da, Jiawei,Zhang, Yi Ge,Li, Gen,et al. Aridity-driven decoupling of delta C-13 between pedogenic carbonate and soil organic matter[J]. 南京大学,2020,48(10):981-985.
APA	Da, Jiawei,Zhang, Yi Ge,Li, Gen,&Ji, Junfeng.(2020).Aridity-driven decoupling of delta C-13 between pedogenic carbonate and soil organic matter.GEOLOGY,48(10),981-985.
MLA	Da, Jiawei,et al."Aridity-driven decoupling of delta C-13 between pedogenic carbonate and soil organic matter".GEOLOGY 48.10(2020):981-985.