Change of tectono-stratigraphic regime in the Australian plate during the 99 Ma (mid-Cretaceous) and 43 Ma (mid Eocene) swerves of the Pacific

• Main Author: Veevers, J. J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2000
• Subjects: Australia; Hotspots bends; Mid-Cretaceous; Mid-Eocene; Pacific; New Zealand; Queensland; Antarc*; Antarctica
• Online Access: https://researchers.mq.edu.au/en/publications/a6e48de6-69f0-4bcb-9100-52e05c7b7722; https://doi.org/10.1130/0091-7613(2000)28<47:COTRIT>2.0.CO;2; http://www.scopus.com/inward/record.url?scp=84879880017&partnerID=8YFLogxK

The clockwise bend at 99 Ma (mid-Cretaceous) in linear volcanic chains in the tropical Pacific coincides with a change from pre-99 Ma head-on Chilean-type subduction of the Pacific plate beneath eastern Gondwana to 99-43 Ma sinistral oblique Mariana-type subduction and strike-slip breakup by simple sea-floor spreading between Australia and Antarctica and by backarc spreading in the southwest Pacific. The 99 Ma breakup of Australia from Antarctica is documented by a mid-Cretaceous unconformity. This tectono-stratigraphic change founded modern Australia, with a mountain chain along an upper plate margin in the east and lowlands on the lower plate margin in the south. The counterclockwise bend at 43 Ma (mid-Eocene)-the Emperor-Hawaiian bend-coincides with the onset of structure in the Challenger Rift of New Zealand, the Eromanga-Cooper basin of central Australia, and the oil-shale grabens of coastal Queensland.