Accession Number : AD0779779

Title :   Investigation on Deformation in Amphibole and Amphibole-Bearing Xenoliths from the Kimberlite Bearing Diatremes on the Colorado Plateau.

Descriptive Note : Final rept. 1 Apr 72-31 Jul 73,

Corporate Author : LAMONT-DOHERTY GEOLOGICAL OBSERVATORY PALISADES N Y

Personal Author(s) : Gavasci,Anna T.

Report Date : 07 DEC 1973

Pagination or Media Count : 17

Abstract : Amphibole from metagabbros from campello Monti, Novara (Italy) show ductile deformation as twinning on (-1,0,1) similarly to experimentally deformed hornblende and tremolite. In nature the most common deformation of amphibole is of the brittle type. This study proves that ductile type of deformation is also possible in a natural environment. Undulatory extinction is common, twinning and deformation lamellae are extremely rare, and, as far as the author is aware, they have not been previously reported. (Author)

Descriptors :   *Rock forming minerals, *Deformation, Crystal structure, Colorado, Italy

Subject Categories : Geology, Geochemistry and Mineralogy

Distribution Statement : APPROVED FOR PUBLIC RELEASE