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Age measurement of the submarine montagnais impact crater
Author(s) -
Bottomley Richard,
York Derek
Publication year - 1988
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl015i012p01409
Subject(s) - impact crater , geology , impact structure , meteorite , submarine , extinction (optical mineralogy) , seismology , paleontology , astrobiology , oceanography , physics
Seven laser‐generated 40 Ar/ 39 Ar age spectra of melt‐rocks from the newly‐described (submarine) Montagnais Crater are presented. While the age spectra are not completely straight forward to interpret, the evidence is very strong that the impact occurred approximately 51 m.y. ago. Thus the Montagnais event is associated with neither the K‐T nor the North American tektite events. Such an age is also totally out of phase with the 26–32 m.y. cycles proposed recently for the meteorite impact and extinction records, as it falls roughly midway between two of the most precisely dated points in such proposed cycles (the K‐T boundary and the North American tektite event).