Neoproterozoic chemostratigraphy and correlation of the Port Askaig glaciation, Dalradian Supergroup of Scotland

被引:97
作者
Brasier, MD
Shields, G
机构
[1] Univ Oxford, Dept Earth Sci, Oxford OX1 3PR, England
[2] Univ Ottawa, Ottawa Carleton Geosci Ctr, Ottawa, ON K1N 6N5, Canada
关键词
Neoproterozoic; Dalradian; glaciation; chemostratigraphy;
D O I
10.1144/jgs.157.5.909
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
The delta(13)C of preglacial carbonates beneath the glaciogenic Port Askaig Formation falls from +5 parts per thousand to negative values, while least-altered Sr-87/Sr-86 values are close to 0.7067. Postglacial 'cap carbonates' of the Bonahaven Formation begin with negative delta(13)C(carb) values, jumping sharply to +11.7 parts per thousand near the top, which we correlate with excursions above the Elbobreen-Wilsonbreen glaciations of Svalbard and putative Sturtian (not Varanger) glaciations elsewhere, dated at c. 720 Ma. Much of the succeeding Terminal Neoproterozoic is missing in NE Svalbard and East Greenland, raising doubts about their use for global Sr and C isotope curves in the Neoproterozoic.
引用
收藏
页码:909 / 914
页数:6
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