Distal Volcanic Ash Deposition as a Cause for Mass Kills of Marine Invertebrates During the Miocene in Northern Patagonia, Argentina

A catastrophic mass mortality event of marine invertebrates, including decapod crustaceans and bivalve mollusks, during the middle Miocene (Tortonian) in northern Patagonia, Argentina, was linked to distal volcanic ash deposition. Despite being at least 650 km away from the Andean volcanic front, the fine volcanic ash introduced into shallow marine environments caused acute respiratory failure in crustaceans, leading to widespread fatalities. The study analyzed sediments and fossils from five localities within the Puerto Madryn Formation using advanced geochemical methods such as SEM, EDS, XRD, petrographic microscopy, and reflected light microscopy, revealing uniform high percentages of volcanic ash across all sites.

MAGUIRE, E. P., FELDMANN, R. M., CASADÍO, S., & SCHWEITZER, C. E. (2016). DISTAL VOLCANIC ASH DEPOSITION AS A CAUSE FOR MASS KILLS OF MARINE INVERTEBRATES DURING THE MIOCENE IN NORTHERN PATAGONIA, ARGENTINA. Palaios, 31(12), 577–591. https://doi.org/10.2110/palo.2016.033