Surface-water acidification and extinction at the Cretaceous-Tertiary boundary

If published estimates of SO2 volatilization and NOx generation by the Cretaceous-Tertiary impact were atmospherically converted to sulfuric and nitric acid, globally dispersed, and rapidly rained out, the resulting acid concentrations would bracket a critical threshold in surface-ocean chemistry. Deposition of masses corresponding to the highest estimates would have provided enough acid to destroy the carbonate-buffering capacity of the upper 100 m of the world ocean and catastrophically reduce surface-ocean pH. Despite the possible effect of the highest estimated acid yields, scenarios that rely on acid rain as the primary explanation of global K-T extinctions are not readily compatible with K-T records of terrestrial and marine survival or culturing studies of modern marine plankton. -from Authors