A lasting question in carbonate geology asks how isolated platforms—the sites of prolific and rapid sedimentation—can drown. To explore how platform drowning occurs, Minzoni et al. document patterns within backstepping platform margin architecture that led up to the drowning of the Yangtze Platform (Triassic, South China). Results reveal that a combination of mechanisms—anoxic basin development and tectonic subsidence/syndepositional faulting—led to drowning of the platform by sinking into toxic bottom waters. Although such a combination of mechanisms is not commonly interpreted as cause of platform demise, the abundance of anoxic tectonically active basins in the stratigraphic record suggests that the combination may be a widespread cause of platform drowning, and patterns of architecture and evolution documented here provide criteria for recognizing tectonically induced drowning in other basins. Finally, the paper philosophically explores the tragedy of platform drowning, and the sense of loss felt at yet another perfectly good platform gone under.
Drowning of the Triassic Yangtze Platform, south China, by tectonic subsidence into toxic deep waters of an anoxic basin by Marcello Minzoni, Daniel J. Lehrmann, Erich Dezoeten, Paul Enos, Paul Montgomery, Adrian Berry, Yanjiao Qin, Yu Meiyi, Brooks B. Ellwood, and Jonathan L. Payne