DOI: 10.1016/j.gloplacha.2016.08.013
论文题名: Tectonomorphic evolution of Marie Byrd Land – Implications for Cenozoic rifting activity and onset of West Antarctic glaciation
作者: Spiegel C. ; Lindow J. ; Kamp P.J.J. ; Meisel O. ; Mukasa S. ; Lisker F. ; Kuhn G. ; Gohl K.
刊名: Global and Planetary Change
ISSN: 0921-8181
出版年: 2016
卷: 145 起始页码: 98
结束页码: 115
语种: 英语
Scopus关键词: Domes
; Geochronology
; Geologic models
; Glacial geology
; Glaciers
; Ice
; Igneous rocks
; Landforms
; Sea level
; Sedimentology
; Tectonics
; Temperature
; Cenozoic tectonics
; Continental ice sheet
; Continental rift
; Low temperatures
; Metasedimentary rocks
; Pine island glaciers
; Tectonic activity
; West antarctic ice sheets
; Sedimentary rocks
英文摘要: The West Antarctic Rift System is one of the largest continental rifts on Earth. Because it is obscured by the West Antarctic Ice Sheet, its evolution is still poorly understood. Here we present the first low-temperature thermochronology data from eastern Marie Byrd Land, an area that stretches ~ 1000 km along the rift system, in order to shed light on its development. Furthermore, we petrographically analysed glacially transported detritus deposited in the marine realm, offshore Marie Byrd Land, to augment the data available from the limited terrestrial exposures. Our data provide information about the subglacial geology, and the tectonic and morphologic history of the rift system. Dominant lithologies of coastal Marie Byrd Land are igneous rocks that intruded (presumably early Paleozoic) low-grade meta-sedimentary rocks. No evidence was found for un-metamorphosed sedimentary rocks exposed beneath the ice. According to the thermochronology data, rifting occurred in two episodes. The earlier occurred between ~ 100 and 60 Ma and led to widespread tectonic denudation and block faulting over large areas of Marie Byrd Land. The later episode started during the Early Oligocene and was confined to western Pine Island Bay area. This Oligocene tectonic activity may be linked kinematically to previously described rift structures reaching into Bellingshausen Sea and beneath Pine Island Glacier, all assumed to be of Cenozoic age. However, our data provide the first direct evidence for Cenozoic tectonic activity along the rift system outside the Ross Sea area. Furthermore, we tentatively suggest that uplift of the Marie Byrd Land dome only started at ~ 20 Ma; that is, nearly 10 Ma later than previously assumed. The Marie Byrd Land dome is the only extensive part of continental West Antarctica elevated above sea level. Since the formation of a continental ice sheet requires a significant area of emergent land, our data, although only based on few samples, imply that extensive glaciation of this part of West Antarctica may have only started since the early Miocene. © 2016 Elsevier B.V. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84986296884&doi=10.1016%2fj.gloplacha.2016.08.013&partnerID=40&md5=df5812cbe126ee0ad77be38cccb4f515
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11622
Appears in Collections: 全球变化的国际研究计划 气候变化与战略
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作者单位: University of Bremen, Department of Geosciences, Postbox 330 440, Bremen, Germany
Recommended Citation:
Spiegel C.,Lindow J.,Kamp P.J.J.,et al. Tectonomorphic evolution of Marie Byrd Land – Implications for Cenozoic rifting activity and onset of West Antarctic glaciation[J]. Global and Planetary Change,2016-01-01,145.