Late Cretaceous dysoxia in a southern high latitude siliciclastic succession, the Otway Basin, southeastern Australia

Abstract

The warm greenhouse world of the Late Cretaceous created oceans that were poorly stratified latitudinally and vertically. Periodically these oceans experienced globally significant events where oxygen minimum zones enveloped the continental margins. Evidence of the effect of one of these Ocean Anoxic Events (OAEs) is preserved in the southern high latitude strata of the offshore Otway Basin in southeast Australia. During the Late Cretaceous, thick successions (up to 6 km) of mudstone-dominated deltaic to upper bathyal sediments (the Otway Delta) were deposited in an elongate inlet (ca. 500 km wide) between Antarctica and Australia located at least 70° S. The initial Turonian strata of this s..