DOI: 10.1016/j.quascirev.2018.02.007
Scopus记录号: 2-s2.0-85042254420
论文题名: Paleoenvironmental and paleohydrochemical conditions of dolomite formation within a saline wetland in arid northwest Australia
作者: Mather C.C. ; Skrzypek G. ; Dogramaci S. ; Grierson P.F.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2018
卷: 185 起始页码: 172
结束页码: 188
语种: 英语
英文关键词: Dolocrete
; Inorganic geochemistry
; Northwest Australia
; Paleohydrology
; Paleolimnology
; Pilbara
; Pleistocene
; Sediment mineralogy
; Stable isotopes
Scopus关键词: Calcite
; Groundwater geochemistry
; Hydrology
; Isotopes
; Minerals
; Paleolimnology
; Saline water
; Surface waters
; Temperature
; Wetlands
; Australia
; Dolocrete
; Inorganic geochemistries
; Paleo-hydrology
; Pilbara
; Pleistocene
; Stable isotopes
; Groundwater
英文摘要: Groundwater dolocrete occurring within the Fortescue Marsh, a large inland wetland in the Pilbara region of northwest Australia, has been investigated to provide paleoenvironmental and paleohydrological records and further the understanding of low temperature dolomite formation in terrestrial settings over the Quaternary Period. Two major phases of groundwater dolocrete formation are apparent from the presence of two distinct units of dolocrete, based on differences in depth, δ18O values and mineral composition. Group 1 (G1) occurs at depth 20–65 m b.g.l. (below ground level) and contains stoichiometric dolomite with δ18O values of −4.02–0.71‰. Group 2 (G2) is shallower (0–23 m b.g.l.), occurring close to the current groundwater level, and contains Ca-rich dolomite ± secondary calcite with a comparatively lower range of δ18O values (−7.74 and −6.03‰). Modelled δ18O values of paleogroundwater from which older G1 dolomite precipitated indicated highly saline source water, which had similar stable oxygen isotope compositions to relatively old brine groundwater within the Marsh, developed under a different hydroclimatic regime. The higher δ18O values suggest highly evaporitic conditions occurred at the Marsh, which may have been a playa lake to saline mud flat environment. In contrast, G2 dolomite precipitated from comparatively fresher water, and modelled δ18O values suggested formation from mixing between inflowing fresher groundwater with saline-brine groundwater within the Marsh. The δ18O values of the calcite indicates formation from brackish to saline groundwater, which suggests this process may be associated with coeval gypsum dissolution. In contrast to the modern hydrology of the Marsh, which is surface water dependent and driven by a flood and drought regime, past conditions conducive to dolomite precipitation suggest a groundwater dependent system, where shallow groundwaters were influenced by intensive evaporation. © 2018 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112260
Appears in Collections: 气候减缓与适应
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作者单位: West Australian Biogeochemistry Centre and Ecosystems Research Group, School of Biological Sciences (M090), The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; Rio Tinto Iron Ore, 152-158 St. George's Terrace, Perth, WA 6000, Australia
Recommended Citation:
Mather C.C.,Skrzypek G.,Dogramaci S.,et al. Paleoenvironmental and paleohydrochemical conditions of dolomite formation within a saline wetland in arid northwest Australia[J]. Quaternary Science Reviews,2018-01-01,185