A radiometric estimate of the duration of sedimentation in the Adelaide geosyncline, south Australia
作者:
W. Compston,
A. R. Crawford,
V. M. Bofinger,
期刊:
Journal of the Geological Society of Australia
(Taylor Available online 1966)
卷期:
Volume 13,
issue 1
页码: 229-276
ISSN:0016-7614
年代: 1966
DOI:10.1080/00167616608728611
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
The Adelaide System forms the uppermost Precambrian sequence in South Australia and the Wooltana Volcanics lie near its base. Though affected by Palaeozoic metamorphism, the least‐altered samples give a minimum age of 850 ± 50 m.y., so that the base of the System is about 900 m.y. old or more. The unmetamorphbsed Roopena Volcanics of northeastern Eyre Peninsula are 1,345 ± 30 m.y. old and if correlated with the Wooltana Volcanics the base of the system becomes about 1,400 m.y. old. The data for the Wooltana Volcanics are consistent with this, provided that even the least‐altered total‐rock samples were open systems during the later metamorphism. Ages of basement in the Mount Painter and Olary districts (1,600 m.y.) and data for Willouran shales overlying the Wooltana Volcanics can fit both minimum and maximum estimates for the Volcanics.
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