Meteorite impact, cryptoexplosion, and shock metamorphism - A perspective on the evidence at the K/T boundaryA perspective on the evidence of a major impact event at the K/T boundary is proposed using field and laboratory studies of terrestrial impact craters. Recent assertions that diagnostic indications of shock metamorphism are also produced in volcanic environments are challenged. A general geological framework of impact structures is developed and the issue of volcanically induced shock metamorphism is examined. Cryptoexplosion is addressed by assessing the geology of two structures: the Slate Islands and Manson, which are often cited by advocates of an internal origin for shock metamorphism as volcanic structures. It is concluded that the link between shock metamorphism and meteorite impact is now established beyond reasonable doubt. The occurrence and worldwide distribution of shocked minerals at the K/T boundary is considered to be the conclusive evidence for a major impact event.
Document ID
19930061698
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Sharpton, V. L. (Lunar and Planetary Inst. Houston, TX, United States)
Grieve, R. A. F. (Geological Survey of Canada Geophysics Div., Ottawa, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1990
Publication Information
Publisher: Geological Society of America (Geological Society Special Publication, No. 247)