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TitleMicroscopic Planar Features in Quartz From Scollard Canyon, Alberta, and the Cretaceous - Tertiary Boundary Event
 
AuthorGrieve, R A F; Alexopoulos, J
SourceCanadian Journal of Earth Sciences vol. 25, no. 9, 1988 p. 1530-1534, https://doi.org/10.1139/e88-144
Year1988
Alt SeriesGeological Survey of Canada, Contribution Series 26787
PublisherCanadian Science Publishing
Documentserial
Lang.English
Mediapaper; on-line; digital
File formatpdf
ProvinceAlberta
NTS82P
AreaScollard Area
Lat/Long WENS-114.0000 -112.0000 52.0000 51.0000
Subjectsextraterrestrial geology; mineralogy; sedimentology; quartz; clays; meteorite craters; iridium; microscopic analyses; sedimentary rocks; extinctions, biotic; Scollard Canyon Formation; Cretaceous; Tertiary
Illustrationsphotomicrographs
AbstractQuartz grains separated from the Cretaceous-Tertiary (K/T) boundary clay at Scollard Canyon, Alberta, have prominent, microscopic planar features. These occur in 15 30% of the grains from the lower 1.5-cm of the boundary clay. They commonly correspond to the Ï and Ï orientations found at known meteorite impact sites and differ from deformation features produced by other dynamic geologic processes. Basal planar features, however, are absent here and at other K/T sites. One possible explanation is that quartz at boundary sites is an incomplete sample of shocked quartz from the postulated K/T impact and unshocked detrital quartz. The source of the shocked quartz most likely was close to the point of impact and near surface. This and previous isotopic data suggest the K/T target site contained a relatively thin upper unit of quartz-bearing crystalline rocks overlying basaltic material, corresponding possibly to thinned continent or a continental margin.
GEOSCAN ID126515

 
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