TY - JOUR
T1 - How strong was pedogenesis in Schirmacher Oasis during the Late Quaternary?
AU - Warrier, Anish Kumar
AU - Mahesh, B. S.
AU - Sebastian, Joju George
AU - Mohan, Rahul
N1 - Funding Information:
This study was carried out as part of the Earth System Science Organization of the Ministry of Earth Sciences, Government of India. We thank the Director, ESSO-NCPOR, Goa, for his constant support and encouragement. AKW thanks R Shankar for providing access to the magnetic instrumentation facility for the measurements. We are thankful to the Antarctic Logistics Division, NCPOR and members of the 28 th Indian Scientific Expedition to Antarctica for their assistance during coring operations. AKW acknowledges the financial support provided by the ESSO-National Centre for Polar and Ocean Research, Ministry of Earth Sciences , in the form of a research project (Sanction: NCPOR/2019/PACER-POP/ES-02 dated July 05, 2019) under the PACER Outreach Programme (POP) initiative, to undertake this research. This is NCPOR contribution no. J-94/2020-21.
Publisher Copyright:
© 2021 Elsevier B.V. and NIPR
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/12
Y1 - 2021/12
N2 - We compare the sediment magnetic properties of two lakes in Schirmacher Oasis, East Antarctica and discuss the intensity of pedogenesis during the Late Quaternary. The magnetic minerals are land-derived with no obliteration of the signal due to bacterial or anthropogenic sources. The magnetic grains of Lake L-49 are much smaller in size compared to Lake Sandy's (low ratio values of IRM20mT/ARM and S20 ). The iron oxide minerals in Lake Sandy's sediments are coarse stable single domain (SSD) and multi-domain (MD) grains with the SSD concentration increasing during the Holocene. Percentage frequency-dependent susceptibility, a marker for pedogenic iron oxide minerals shows a similar trend for Lake Sandy, with the values remaining low during the Last Glacial Stage (LGS) and increasing towards the Holocene. Such a pattern is not observed in the sediments of Lake L-49. Principal Component Analysis reveals a relatively stronger intensity of pedogenesis in the Lake Sandy catchment during the deglaciation. From the data, we observe that even though pedogenesis is active, the intensity is not strong enough to form superparamagnetic (SP) grains. The peaks in χfd for both the lakes show a direct relationship with Antarctic Isotope Maximum events recorded in an ice-core data suggesting that χfd can be used as a proxy for paleo-pedogenesis in Antarctica.
AB - We compare the sediment magnetic properties of two lakes in Schirmacher Oasis, East Antarctica and discuss the intensity of pedogenesis during the Late Quaternary. The magnetic minerals are land-derived with no obliteration of the signal due to bacterial or anthropogenic sources. The magnetic grains of Lake L-49 are much smaller in size compared to Lake Sandy's (low ratio values of IRM20mT/ARM and S20 ). The iron oxide minerals in Lake Sandy's sediments are coarse stable single domain (SSD) and multi-domain (MD) grains with the SSD concentration increasing during the Holocene. Percentage frequency-dependent susceptibility, a marker for pedogenic iron oxide minerals shows a similar trend for Lake Sandy, with the values remaining low during the Last Glacial Stage (LGS) and increasing towards the Holocene. Such a pattern is not observed in the sediments of Lake L-49. Principal Component Analysis reveals a relatively stronger intensity of pedogenesis in the Lake Sandy catchment during the deglaciation. From the data, we observe that even though pedogenesis is active, the intensity is not strong enough to form superparamagnetic (SP) grains. The peaks in χfd for both the lakes show a direct relationship with Antarctic Isotope Maximum events recorded in an ice-core data suggesting that χfd can be used as a proxy for paleo-pedogenesis in Antarctica.
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U2 - 10.1016/j.polar.2021.100636
DO - 10.1016/j.polar.2021.100636
M3 - Article
AN - SCOPUS:85099840393
SN - 1873-9652
VL - 30
JO - Polar Science
JF - Polar Science
M1 - 100636
ER -