DOI: 10.1016/j.earscirev.2021.103756
论文题名: Evaluation of physical and chemical proxies used to interpret past glaciations with a focus on the late Paleozoic Ice Age
作者: Isbell J.L. ; Vesely F.F. ; Rosa E.L.M. ; Pauls K.N. ; Fedorchuk N.D. ; Ives L.R.W. ; McNall N.B. ; Litwin S.A. ; Borucki M.K. ; Malone J.E. ; Kusick A.R.
刊名: Earth Science Reviews
ISSN: 00128252
出版年: 2021
卷: 221 语种: 英语
中文关键词: Far-field proxies
; Glacial isostatic adjustment
; Glacial proxies
; Glacioeustacy
; Late Paleozoic Ice Age
; Near-field proxies
英文摘要: The late Paleozoic Ice Age (LPIA) was one of Earth's most important Phanerozoic climatic events lasting for over 100 Mys. Despite its importance, its history is controversial with two hypotheses that portray glaciation differently (Fig. 1). Traditional views characterize the LPIA as a continuous glacial event that lasted from the Middle Mississippian until the Late Permian with a massive ice sheet that covered Gondwana throughout this interval. This approach often uses only one or two proxies to define the glaciation. The other emerging hypothesis suggests that numerous ice sheets occurred in Gondwana with individual glacial events lasting up to 10 Mys alternating with glacial minima/non-glacial intervals of similar duration. Both views are still prevalent. Both near- and far-field proxies are used to define the ice age. Near-field proxies include the occurrence/absence of diamictites, glaciotectonic deposits/landforms, striated clasts and clast pavements, outsized clasts (dropstones), rhythmites, cyclic diamictite-bearing successions, glendonites, grooved and striated surfaces, streamline landforms, and U-shaped paleovalleys. Detrital zircons and chemical index of alteration (CIA) studies help to delineate the occurrence, extent, and location of glaciation. Multiple complexities occur with the use of these proxies as different non-glacial processes and driving factors can produce similar features or results. Far-field proxies focus on identifying changes in eustacy. These include the occurrence of cyclic successions composed of alternating nonmarine and marine strata (cyclothems), depth of incised valleys, paleotopographic relief, phosphatic black shales, and changing oxygen isotope ratios. Like the near-field record, far-field proxies are complex indicators with varied nuances that make their application challenging. Here we discuss the limitations and use of these proxies and promote a multiproxy approach to investigating Earth's glacial intervals. We suggest that studies incorporate multiple proxies coupled with detailed environmental, paleoflow, and paleogeographic analyses to better constrain the occurrence, timing, and extent of glaciation and its influence on global systems. This approach will provide a robust view of the LPIA. We also consider the magnitude and nature of sea-level response to changing ice volumes by discussing ice-volume fluctuations, basin subsidence's modification of glacioeustacy, and sea-level's response to global isostatic adjustment (GIA). In considering these features, it becomes apparent that glacioeustacy is more complex than previously envisioned. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/166422
Appears in Collections: 气候变化与战略
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作者单位: Department of Geosciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Ave., Milwaukee, WI 53211, United States; Departamento de Geologia, UFPR - Universidade Federal do Paraná, Caixa Postal 19001, Curitiba, PR CEP 81531-980, Brazil; Department of Earth Science, Southern Connecticut State University, New Haven, CT 06515, United States
Recommended Citation:
Isbell J.L.,Vesely F.F.,Rosa E.L.M.,et al. Evaluation of physical and chemical proxies used to interpret past glaciations with a focus on the late Paleozoic Ice Age[J]. Earth Science Reviews,2021-01-01,221