Mathematics – Logic
Scientific paper
May 1984
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1984sci...224..867b&link_type=abstract
Science (ISSN 0036-8075), vol. 224, May 25, 1984, p. 867-869.
Mathematics
Logic
128
Iridium, Metamorphism (Geology), Meteoritic Damage, Mineralogy, Quartz, Crystal Lattices, Electron Microscopy, Montana, Refractivity, Stratosphere, Cretaceous-Tertiary Event, Impacts, Mineralogy, Anomalies, Iridium, Abundance, Quartz, Feldspar, Grains, Features, Crystallography, Refractive Index, Characterisitcs, Shock, Metamorphism, Velocity
Scientific paper
A thin claystone layer found in nonmarine rocks at the polynological Cretaceous-Tertiary boundary in eastern Montana contains an anomalously high value of iridium. The nonclay fraction is mostly quartz with minor feldspar, and some of these grains dislay planar features. These planar features are related to specific crystallographic directions in the quartz lattice. The shocked quartz grains also exhibit asterism and have lowered refractive indices. All these mineralogical features are characteristic of shock metamorphism and are compelling evidence that the shocked grains are the product of a high velocity impact between a large extraterrestrial body and the earth. The shocked minerals represent silicic target material injected into the stratosphere by the impact of the projectile.
Bohor Bruce F.
Foord Eugene E.
Modreski Peter J.
Triplehorn D. M.
No associations
LandOfFree
Mineralogic evidence for an impact event at the Cretaceous-Tertiary boundary does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Mineralogic evidence for an impact event at the Cretaceous-Tertiary boundary, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mineralogic evidence for an impact event at the Cretaceous-Tertiary boundary will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1370049