At the end of the Cretaceous (65 Ma ago) the Earth suffered the great biological
crisis when estimated 60% of the former species, among them the dinosaurs, became extinct.
More than 3000 papers were published for the last 30 years, concerning the discussion this
question but the decision remains unresolved. Authors propose the new approach to this problem
based on the detailed micropalaeontological, lithological, geochemical, nanomineralogical,
isotopic and petromagnetic investigations of the unique sedimentary sequence at the
Cretaceous-Paleogene boundary in the Gams area, Eastern Alps, Austria.
The conclusions drawn from the results of analysis principally differ
from all preexisting data on the transitional layer between the Cretaceous and Paleogene and
provide another look at the reasons for the mass extinction of living organisms at 65 Ma ago.
These data eliminate the need for opposing volcanism to an impact event: both took place, but
the changes in the biota were induced by volcanism, as also was the appearance of the Ir anomaly
itself, whereas the fall of a cosmic body occurred approximately 500–800 years later.
Citation: Grachev A. F., Ed. (2009), The K/T Boundary of Gams (Eastern Alps, Austria) and the Nature of
Terminal Cretaceous Mass Extinction, Publ. GC RAS, Moscow, 199pp., doi:10.2205/2009-GAMSbook. (Print companion published by
the Geological Survey of Austria, Abhandlungen, 63, 2009, 199pp.)