THE LATE EARLY EOCENE MONTAGNAIS BOLIDE - NO IMPACT ON BIOTIC DIVERSITY

There are great difficulties associated with the comparison of the record of mass extinctions with that of impact craters because, as Sepkoski and Raup (1986) pointed out, both are dated by totally independent means. There is also a question as to the size required for an impacting object to provoke mass extinction. The Montagnais impact crater is the first impact event which can be directly and precisely correlated to the marine stratigraphic record through biostratigraphic means. Its occurrence during the late early Eocene, between 52.6 and 53.4 Ma, at a time when Cenozoic diversity was at its peak, indicates that no global effect on biologic diversity can be expected from the impact in the ocean of a bolide 1.5 to 3 km in diameter. -from Authors