Other
Scientific paper
Dec 1986
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1986e%26psl..81...57b&link_type=abstract
Earth and Planetary Science Letters (ISSN 0012-821X), vol. 81, no. 1, Dec. 1986, p. 57-66.
Other
33
Asteroids, Atmospheric Entry, Ejecta, Ferrites, Magnetic Materials, Chondrites, Clays, Craters, Crystallization, Electron Microscopy, Neutron Activation Analysis, Spain, X Ray Diffraction
Scientific paper
The results of an analysis of samples separated from the Cretaceous-Tertiary (K-T) boundary clay at Caravaca, Spain are presented. Magnetically fractionated samples were irradiated with thermal neutrons, and the element concentrations were determined by gamma-ray counting. The magnetic mineral separated from the basal layer of the K-T boundary is a spinel-type phase having the composition of magnesioferrite, and is high (about 29 ppb) in iridium. This spinel-type phase and others of the spinel group found in K-T boundary clays have been proposed to represent unaltered remnants of ejecta deposited from an earth-girdling dust cloud formed from the impact of an asteroid or other large bolide at the end of the Cretaceous period. Major element composition (high Cr and Ni) and trace element ratios of the analyzed samples indicate either an extraterrestrial or mantle source for the magnesioferrite. On the basis of the crystal morphology and general compositon of the grains, rapid crystallization at high temperature is indicated, most likely directly from a vapor phase or emanating cloud and in an environment of moderate oxygen fugacity.
Bohor Bruce F.
Foord Eugene E.
Ganapathy Ramachandran
No associations
LandOfFree
Magnesioferrite from the Cretaceous-Tertiary boundary, Caravaca, Spain 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 Magnesioferrite from the Cretaceous-Tertiary boundary, Caravaca, Spain, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnesioferrite from the Cretaceous-Tertiary boundary, Caravaca, Spain will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1121950