A dynamic fluvial model for the Sydney Basin

• Published in: Journal of the Geological Society of Australia
• Main Authors: Conaghan, Patrick J., Jones, Gilbert, McDonnell, Kevin L., Royce, Keith
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1982
• Subjects: Mackay; Blue Mountains; Antarc*; Antarctica
• Online Access: https://researchers.mq.edu.au/en/publications/b6508cab-801b-488d-bb70-8dc4d866bff5; https://doi.org/10.1080/00167618208729194; http://www.scopus.com/inward/record.url?scp=0020469488&partnerID=8YFLogxK

Late Permian and Triassic successions of the Sydney Basin, exposed in cliffs of the north coast, south coast and Blue Mountains, include sandstones in which quartz content increases up-sequence and palaeocurrents swing from southwesterly through southeasterly to northeasterly. These basin-wide phenomena are interpreted to have resulted from the northeasterly migration of a drainage net, in which northeasterly-flowing tributaries bearing quartz sand from the craton met southwesterly-flowing tributaries bearing labile sediment from an arcuate rim-orogen, and blended in a southeasterly-flowing trunk stream down the axis of a foredeep. Migration of the drainage net records the retreat of an arc-derived clastic wedge in the latter part of a megacycle which extends from the top of the mid-Permian Nowra Sandstone to the top of the mid-Triassic Hawkesbury Sandstone. The same megacycle occurs in the Bowen Basin, and may also occur in the Nilsen-Mackay Basin of Antarctica.