Sediment facies and environments of deposition on Cretaceous Pacific carbonate platforms: an overview of dredged rocks from western Pacific guyots

Abstract

Many years of dredging of Cretaceous guyots in the western Pacific Ocean have shown the widespread occurrence of drowned carbonate platforms that were active in the Early to middle Cretaceous. Through petrographic analysis of available dredged limestone samples from these guyots, eight limestone lithofacies are distinguished. The eight lithofacies are used to form a composite image of the depositional environments on the Cretaceous Pacific carbonate platforms. The most striking aspect of the recovered lithofacies is the strong contrast in depositional energy presented by the platform-margin and platform-interior facies. The absence of evidence of reef-framework structures at the platform margins suggests that wave and current energy in the open ocean either was not very great in the Cretaceous Pacific Ocean, or was efficiently damped by lack of depositional relief. -from Author