Environmental Effects of Deccan Volcanism During the Late Cretaceous

Abstract

The use of sedimentary mercury has long been suggested to be the best tool to identify periods of major volcanism in the sedimentary record (LIP marks). Comprehensive studies seem to indicate that most extinction events, oceanic anoxic events and other environmental crises have been associated with sedimentary Hg anomalies. However, since mercury has strong affinities to organic matter, normalization with the total organic carbon (TOC) is necessary to properly assess and compare such anomalies with each other. Using such methods, this paper sets to comprehensively evaluate the sedimentary mercury deposition present in the areas across Mexico near the Chicxulub impact site. Results suggest that Hg/TOC anomalies recorded in the rock record not only conclusively predate the Chicxulub impact but were likely derived from Deccan Volcanism in India, thereby trivializing the significance of the Chicxulub as a contributing factor to the Cretaceous mass extinction.