How strong was pedogenesis in Schirmacher Oasis during the Late Quaternary?
| Autor: | Badanal Siddaiah Mahesh, Joju George Sebastian, Anish Kumar Warrier, Rahul Mohan |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
0106 biological sciences
010504 meteorology & atmospheric sciences Iron oxide Drainage basin Geochemistry Aquatic Science 01 natural sciences Iron oxides chemistry.chemical_compound Deglaciation Glacial period Ecology Evolution Behavior and Systematics Holocene 0105 earth and related environmental sciences geography Pedogenesis geography.geographical_feature_category Ecology 010604 marine biology & hydrobiology Sediment Schirmacher oasis East Antarctica Magnetic grain size Environmental magnetism chemistry General Earth and Planetary Sciences Quaternary Geology |
| Zdroj: | Polar Science. 30:100636 |
| ISSN: | 1873-9652 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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