DOI: 10.1016/j.palaeo.2014.08.007
论文题名: Glacial-interglacial climatic variations at the Schirmacher Oasis, East Antarctica: The first report from environmental magnetism
作者: Warrier A.K. ; Mahesh B.S. ; Mohan R. ; Shankar R. ; Asthana R. ; Ravindra R.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2014
卷: 412 起始页码: 249
结束页码: 260
语种: 英语
英文关键词: East Antarctica
; Environmental magnetism
; Lake sediments
; Mechanical weathering
; Pedogenesis
; Schirmacher Oasis
英文摘要: We discuss in this paper the first detailed environmental magnetic record of glacial-interglacial climatic variations in the Schirmacher Oasis, East Antarctica. We determined environmental magnetic properties and inter-parametric ratios (χlf, χfd %, χARM, SIRM, χARM/SIRM, χARM/χlf, χARM/χfd, SIRM/χlf, S-ratio and HIRM) for sediment samples of a core from the Sandy Lake. Accelerator mass spectrometer (AMS) 14C dates were obtained on the organic matter from bulk sediment samples. The sediment core spans the past ~42.5cal. ka B.P. The magnetic minerals are mainly detrital and catchment-derived, as there is no evidence for the presence of authigenic greigite, bacterial magnetite or diagenetic dissolution. The last glacial period is characterized by a high concentration of ferrimagnetic minerals such as titanomagnetite (high values of χlf, SIRM etc.) and coarse magnetic grain size (low χARM/SIRM and χARM/χlf values and high S-ratio values). Deglaciation in the Schirmacher Oasis began around 21cal. ka B.P. as suggested by the low magnetic mineral concentration. The Holocene period is characterized by relatively warm climatic events as seen in the low values of magnetic susceptibility which is primarily contributed by fine-grained titanomagnetite resulting from pedogenesis (high χfd % values). Several of the relatively warm and cold events that we deciphered from the environmental magnetic data are correlatable with lake sediments from the Schirmacher Oasis and other ice-free areas in East Antarctica and from ice-core records on the Antarctic Plateau. © 2014 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69229
Appears in Collections: 过去全球变化的重建
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作者单位: National Centre for Antarctic and Ocean Research, Earth System Sciences Organization (ESSO), Ministry of Earth Sciences, Government of India, Headland Sada, Vasco, Goa, India; Department of Marine Geology, Mangalore University, Mangalagangotri, Karnataka, India; Human Resource Development Division, CHQ 27, J.L.N. Road, Kolkata, India; Earth System Sciences Organization (ESSO), Ministry of Earth Sciences, Government of India, Prithvi Bhawan, Lodhi Road, New Delhi, India
Recommended Citation:
Warrier A.K.,Mahesh B.S.,Mohan R.,et al. Glacial-interglacial climatic variations at the Schirmacher Oasis, East Antarctica: The first report from environmental magnetism[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2014-01-01,412