DOI: 10.1016/j.quascirev.2015.06.020
Scopus记录号: 2-s2.0-84935123492
论文题名: Monsoon source shifts during the drying mid-Holocene: Biomarker isotope based evidence from the core 'monsoon zone' (CMZ) of India
作者: Sarkar S. ; Prasad S. ; Wilkes H. ; Riedel N. ; Stebich M. ; Basavaiah N. ; Sachse D.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 123 起始页码: 144
结束页码: 157
语种: 英语
英文关键词: Compound-specific stable isotopic composition
; Holocene
; Indian Summer Monsoon
; Lipid biomarkers
; Lonar Lake
Scopus关键词: Biomarkers
; Catchments
; Climate change
; Eutrophication
; Isotopes
; Lakes
; Paraffins
; Vegetation
; Holocenes
; Indian summer monsoon
; Lipid biomarkers
; Lonar lakes
; Stable isotopic compositions
; Atmospheric thermodynamics
; alcohol
; alkalinity
; alkane
; arid environment
; atmospheric circulation
; biomarker
; C4 plant
; carbon isotope
; catchment
; climate change
; climate variation
; cyanobacterium
; dominance
; economic analysis
; eutrophication
; grass
; Holocene
; isotopic analysis
; isotopic composition
; lacustrine deposit
; lipid
; livestock farming
; monsoon
; paleohydrology
; proxy climate record
; reconstruction
; salinity
; seasonality
; sediment core
; spatiotemporal analysis
; stable isotope
; vegetation structure
; water column
; woody plant
; India
; Lonar Lake
; Maharashtra
; Cyanobacteria
; Poaceae
英文摘要: A better understanding of past variations of the Indian Summer Monsoon (ISM), that plays a vital role for the still largely agro-based economy in India, can lead to a better assessment of its potential impact under global climate change scenarios. However, our knowledge of spatiotemporal patterns of ISM strength is limited due to the lack of high-resolution, continental paleohydrological records. Here, we reconstruct centennial-scale hydrological variability during the Holocene associated to changes in the intensity of the ISM based on a record of lipid biomarker abundances and compound-specific stable isotopic composition of a 10m long sediment core from saline-alkaline Lonar Lake, situated in the core 'monsoon zone' of central India.We identified three main periods of distinct hydrology during the Holocene in central India. The period between 10.1 and 6calka BP was likely the wettest during the Holocene. Lower average chain length (ACL) index values (29.4-28.6) and negative δ13Cwax values (-34.8‰ to-27.8‰) of leaf wax n-alkanes indicate the dominance of woody C3 vegetation in the catchment, and negative δDwax values (concentration weighted average) (-171‰ to-147‰) suggest a wet period due to an intensified monsoon. After 6calka BP, a gradual shift to less negative δ13Cwax values (particularly for the grass derived n-C31 ) and appearance of the triterpene lipid tetrahymanol, generally considered as a marker for salinity and water column stratification, mark the onset of drier conditions. At 5.1calka BP an increasing flux of leaf wax n-alkanes along with the highest flux of tetrahymanol indicate a major lowering of the lake level. Between 4.8 and 4calka BP, we find evidence for a transition to arid conditions, indicated by high and strongly variable tetrahymanol flux. In addition, a pronounced shift to less negative δ13Cwax values, in particular for n-C31 (-25.2‰ to-22.8‰), during this period indicates a change of dominant vegetation to C4 grasses. In agreement with other proxy data, such as deposition of evaporite minerals, we interpret this period to reflect the driest conditions in the region during the last 10.1ka. This transition led to protracted late Holocene arid conditions after 4ka with the presence of a permanent saline lake, supported by the sustained presence of tetrahymanol and more positive average δDwax values (-122‰ to-141‰). A late Holocene peak of cyanobacterial biomarker input at 1.3calka BP might represent an event of lake eutrophication, possibly due to human impact and the onset of cattle/livestock farming in the catchment.A unique feature of our record is the presence of a distinct transitional period between 4.8 and 4calka BP, which was characterized by some of the most negative δDwax values during the Holocene (up to-180‰), when all other proxy data indicate the driest conditions during the Holocene. These negative δDwax values can as such most reasonably be explained by a shift in moisture source area and/or pathways or rainfall seasonality during this transitional period. We hypothesize that orbital induced weakening of the summer solar insolation and associated reorganization of the general atmospheric circulation, as a possible southward displacement of the tropical rainbelt, led to an unstable hydroclimate in central India between 4.8 and 4ka. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59869
Appears in Collections: 过去全球变化的重建
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作者单位: Institute of Earth and Environmental Science, University of Potsdam, Karl-Liebknecht-Straße 24-25, Potsdam, Germany; Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Section 4.3, Organic Geochemistry, Telegrafenberg, Potsdam, Germany; Senckenberg Research Institute, Research Station of Quaternary Palaeontology, Am Jakobskirchhof 4, Weimar, Germany; Indian Institute of Geomagnetism, New Panvel, Navi Mumbai, India; Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Section 5.1, Geomorphology, Organic Surface Geochemistry Lab, Telegrafenberg, Potsdam, Germany
Recommended Citation:
Sarkar S.,Prasad S.,Wilkes H.,et al. Monsoon source shifts during the drying mid-Holocene: Biomarker isotope based evidence from the core 'monsoon zone' (CMZ) of India[J]. Quaternary Science Reviews,2015-01-01,123