TY - JOUR
T1 - Stable isotopic composition of pedogenic carbonates from the eastern margin of the Thar Desert, Rajasthan, India
AU - Achyuthan, Hema
AU - Quade, Jay
AU - Roe, Lois
AU - Placzek, Christa
N1 - Funding Information:
The authors thank C. Latorre for discussions, Prof. V. Baker for support and encouragement and Dr. V.N. Misra, Dr. S.N.Rajaguru, and Dr. Jon Patchett for providing facilities and assistance during the course of this work. The US Education Foundation in India supported this research as a Post Docotral Fulbright Fellowship to Hema Achyuthan and NSF Grant EAR-9304923 to Jay Quade.
PY - 2007/3
Y1 - 2007/3
N2 - Pedogenic carbonates in a 19 m-thick dune section (16R) at Didwana, and several shorter profiles from the eastern margin of the Thar Desert, Rajasthan, were studied for their stable isotope composition. Carbon isotope results show the C4 biomass (grasses?) has dominated local vegetation for most of the 250,000 years represented by the 16R section. Our results display a decrease in δ18O and δ13C values during the last interglacial and early glacial periods. The higher δ13C values in our dune records correlate to episodes in the strong upwelling and decreased sedimentation rates in Indian Ocean cores, probably the result of a strong Asian Monsoon. The high δ13C values may, therefore, denote the expansion of C4 vegetation in response to warm, wetter monsoon circulation. Conversely, low δ18O and δ13C values mark the expansion of C3 vegetation, probably caused by enhanced winter rains and lower temperatures.
AB - Pedogenic carbonates in a 19 m-thick dune section (16R) at Didwana, and several shorter profiles from the eastern margin of the Thar Desert, Rajasthan, were studied for their stable isotope composition. Carbon isotope results show the C4 biomass (grasses?) has dominated local vegetation for most of the 250,000 years represented by the 16R section. Our results display a decrease in δ18O and δ13C values during the last interglacial and early glacial periods. The higher δ13C values in our dune records correlate to episodes in the strong upwelling and decreased sedimentation rates in Indian Ocean cores, probably the result of a strong Asian Monsoon. The high δ13C values may, therefore, denote the expansion of C4 vegetation in response to warm, wetter monsoon circulation. Conversely, low δ18O and δ13C values mark the expansion of C3 vegetation, probably caused by enhanced winter rains and lower temperatures.
UR - http://www.scopus.com/inward/record.url?scp=33847666931&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33847666931&partnerID=8YFLogxK
U2 - 10.1016/j.quaint.2006.10.031
DO - 10.1016/j.quaint.2006.10.031
M3 - Article
AN - SCOPUS:33847666931
SN - 1040-6182
VL - 162-163
SP - 50
EP - 60
JO - Quaternary International
JF - Quaternary International
ER -