Sequence stratigraphy and evolution of a basin‐slope succession: The Late Proterozoic Wonoka Formation, Flinders Ranges, South Australia
作者:
P. A. DiBona,
C. C.von der Borch,
N. Christie‐Blick,
期刊:
Australian Journal of Earth Sciences
(Taylor Available online 1990)
卷期:
Volume 37,
issue 2
页码: 135-145
ISSN:0812-0099
年代: 1990
DOI:10.1080/08120099008727916
出版商: Taylor & Francis Group
关键词: Adelaide Geosyncline;basin slope evolution;sequence stratigraphy;Wonoka Formation
数据来源: Taylor
摘要:
A shelf to basin‐slope transition is vertically and laterally exposed within the Late Proterozoic Wonoka Formation in the northern Flinders Ranges of South Australia. The shelf to basin‐slope transition can be divided into four units (C to F) which are defined on the basis of facies, sedimentary structures, contacts, stratal geometry, and the type and abundance of down‐slope mass movement. The lowest unit (C) is mudstone dominated and parallel laminated with rare synsedimentary slides. Unit D, a thin, resedimented siliciclastic‐carbonate unit deposited on a sequence boundary at the end of unit C progradation, displays a lateral facies change from well bedded ‘outer shelf deposits in the east to basin‐slope debris flows in the west. Unit E forms a shallowing and coarsening upward succession from ‘outer shelf siltstone to ‘inner shelf storm wave influenced sandstone deposits. The unit thickens westwards, in the interpreted down‐slope direction, where it becomes finer grained and thinner bedded and displays an increasing abundance of synsedimentary slides. Unit F, deposited on an inferred shelf to basin‐slope transition, coarsens and shallows upward, thickens to the west and contains the highest percentage of sandstone and synsedimentary slides. Unit G, deposited at shelf depths, also shallows and coarsens upward from a thin, basal carbonate‐siliciclastic member, with sandstone increasing upsection to a gradational contact with the Pound Subgroup.
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