EOAS Colloquium: Dr. Gerta Keller, Princeton
Accelerating Deccan eruptions,
runaway climate change and the end-Cretaceous mass Extinction
Gerta Keller, Geosciences Department, Princeton University
Abstract: India’s Deccan Volcanic Province (DVP) emerged as likely primary cause for the end-Cretaceous mass extinction thus challenging the long-held belief that the Chicxulub impact is the sole culprit. Over a span of ~750 ky (magnetochron C29r) ~80% of Deccan eruptions flooded the Indian continent with ~1.5 million km3 of lava forming >3200 m high mountains, with accelerated eruptions during ~50 ky before and after the mass extinction. Volcanic eruptions released tens of thousands of gigatons of CO2, SO2 and other gases that resulted in rapid global climate warming by 3-4 ºC in the oceans and 7-8 ºC on land accompanied by short cool events, acid rain and ocean acidification. The mass extinction in planktic foraminifera is directly recorded between the four longest lava flows >1000 km across India. On a global basis the discovery of major mercury (Hg) anomalies in marine sediments mark massive Deccan volcanic eruptions permitting new insights into the rate and tempo of environmental change, mass extinction and recovery directly tied to Deccan volcanism.