DOI: 10.1016/j.palaeo.2016.12.019
论文题名: Aeolianite, calcrete/microbialite and karst in southwestern Australia as indicators of Middle to Late Quaternary palaeoclimates
作者: Lipar M. ; Webb J.A. ; Cupper M.L. ; Wang N.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2017
卷: 470 起始页码: 11
结束页码: 29
语种: 英语
英文关键词: Calcarenite
; Glacial period
; Holocene
; Interglacial period
; Pleistocene
; Tamala limestone
英文摘要: The mid-Late Pleistocene and Holocene aeolianites of the Tamala Limestone on the northern Swan Coastal Plain in southwestern Western Australia consist of six members that show cyclic deposition of coastal aeolianite, overlain by calcrete/microbialite, karstified surface and palaeosol. Field work, combined with mineralogical, chemical, stable isotope analysis and uranium-thorium (U/Th) and optically stimulated luminescence (OSL) dating, provides an insight into the repetitive glacial and interglacial climatic periods over the past 500 kyr. Deposition of the carbonate aeolianites occurred during interglacial episodes (marine isotope stage (MIS) 1, 5, 7, 9, 11, and possibly 13), due to migration of coastal dunes under the influence of strong southerly to southwesterly winds. Rainfall was insufficient to support vegetation cover on the dunes, and so was probably limited or seasonal. The transition from interglacial to glacial climates was characterised by higher effective rainfall, accompanied by aeolianite dissolution and karstification. During the colder climates and less effective rainfall of the glacial periods, there was no carbonate sand deposition; instead laminated microbialite and/or laminar calcrete formed, followed by palaeosol formation. The oxygen isotope composition of the microbialites indicates average temperatures during glacial periods ~ 4 °C − 8 °C lower than today, and δ13C values demonstrate a higher proportion of C4 plants and therefore a drier or more seasonal climate. Data from individual members of the Tamala Limestone show that the wettest interglacial period was MIS 5, when extensive karstification and pinnacle development occurred, and rainfall was probably higher than at any other time in the past 500 kyr. Of the glacial periods, MIS 10 was relatively wet or less seasonal, whereas MIS 8 and the Last Glacial Maximum (LGM) were relatively dry and windy. The low rainfall during the peak of the glacial periods was probably intensified by colder water offshore, due to weakening of the Leeuwin Current and its replacement by the cold, north-flowing West Australian Current. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/67927
Appears in Collections: 过去全球变化的重建
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作者单位: Environmental Geoscience, Department of Ecology, Environment and Evolution, La Trobe University, Victoria, Bundoora, Melbourne, Australia; School of Earth Sciences, The University of Melbourne, Melbourne, Victoria, Australia; School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington, New Zealand
Recommended Citation:
Lipar M.,Webb J.A.,Cupper M.L.,et al. Aeolianite, calcrete/microbialite and karst in southwestern Australia as indicators of Middle to Late Quaternary palaeoclimates[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2017-01-01,470