干旱区生态环境知识资源中心(Arid): High-resolution record of stable isotopes in soil carbonates reveals environmental dynamics in an arid region (central Iran) during the last 32 ka

Arid

DOI	10.3389/feart.2023.1154544
	High-resolution record of stable isotopes in soil carbonates reveals environmental dynamics in an arid region (central Iran) during the last 32 ka
	Bayat, Omid; Karimi, Alireza; May, Jan-Hendrik; Fattahi, Morteza; Wiesenberg, Guido L. B.; Egli, Markus
通讯作者	Karimi, A
来源期刊	FRONTIERS IN EARTH SCIENCE
EISSN	2296-6463
出版年	2023
卷号	11
英文摘要	Although central Iran is pivotal for palaeoclimatic correlations, palaeoenvironmental data for this region is very sparse and a reliable chronology for pedogenic features is lacking. We therefore tried to answer the question how the environmental conditions and, in particular, the climate developed over time by using the isotopic signatures of pedogenic carbonates. We present a chronology of pedogenic carbonates in association with stable carbon and oxygen isotopes in both the matrix and coating carbonates of a relict palaeosol (Baharan palaeosol) in central Iran to understand the dynamics of environmental changes in this region during the late Quaternary. The palaeosol experienced several episodes of leaching during pedogenesis as reflected in its morphology (carbonate coatings under the rock fractions) and geochemical characteristics (Ba/Sr ratios). The delta O-18 values of both the matrix and coating carbonates in the upper 60 cm (especially in the upper 20 cm) of the pedon are enriched (similar to 4%) compared to the subsoil and are mainly related to the impact of evaporation. Moreover, the delta C-13 values of the carbonates are in isotopic disequilibrium with the modern vegetation cover (desert shrubs) of the study area and are enriched in different degrees. The carbonates in the top 60 cm are formed by the input of atmospheric CO2 and calcareous dust while deeper carbonates formed in an environment exhibiting a higher contribution of C-4 plants. Based on the radiocarbon chronology of carbonate coatings, it seems that three main stages of palaeoenvironmental changes occurred in the region during the last 32 ka. The first stage lasted ca. 5,000 years (between 31.6 and 26.0 ka) and was accompanied by deep leaching under sub-humid climatic conditions and the expansion of C-4 plants. Under the dominance of semi-arid conditions during the second stage until the late Holocene, a gradual increase in the delta O-18 values and aridity occurred in the region. The last phase in the late Holocene was characterised by the establishment of an arid and evaporative environment with a sparse vegetation cover. A climatic correlation using the oxygen isotopic composition of secondary carbonates from the Baharan palaeosol, Soreq Cave (the Levant) and Hoti Cave (Oman; both having speleothems records) suggested a climatic connection between central Iran and the eastern Mediterranean during the late Pleistocene and between central Iran and northern Oman during the late Holocene.
英文关键词	relict palaeosols pedogenic carbonates carbonate coatings carbon and oxygen isotopes radiocarbon chronology late quaternary paleoclimate western Asia
类型	Article
语种	英语
开放获取类型	gold
收录类别	SCI-E
WOS记录号	WOS:001004914800001
WOS关键词	PEDOGENIC CARBONATES ; RADIOCARBON CALIBRATION ; ATACAMA DESERT ; THAR DESERT ; PRECIPITATION ; OXYGEN ; HOLOCENE ; CLIMATE ; VARIABILITY ; LOESS
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/396484
推荐引用方式 GB/T 7714	Bayat, Omid,Karimi, Alireza,May, Jan-Hendrik,et al. High-resolution record of stable isotopes in soil carbonates reveals environmental dynamics in an arid region (central Iran) during the last 32 ka[J],2023,11.
APA	Bayat, Omid,Karimi, Alireza,May, Jan-Hendrik,Fattahi, Morteza,Wiesenberg, Guido L. B.,&Egli, Markus.(2023).High-resolution record of stable isotopes in soil carbonates reveals environmental dynamics in an arid region (central Iran) during the last 32 ka.FRONTIERS IN EARTH SCIENCE,11.
MLA	Bayat, Omid,et al."High-resolution record of stable isotopes in soil carbonates reveals environmental dynamics in an arid region (central Iran) during the last 32 ka".FRONTIERS IN EARTH SCIENCE 11(2023).