A Grenville-age layered intrusion in the subsurface of west Texas: petrology, petrography, and possible tectonic setting

H. Kargi, C. G. Barnes

Research output: Contribution to journalArticle

16 Scopus citations

Abstract

The Nellie intrusion is a thick (more than 4420 m) mafic to ultramafic layered intrusion with a radiometric age of ~1163 Ma. Rock types change abruptly with stratigraphic height and include norite, pyroxenite, gabbronorite, hornblende gabbro, gabbro, anorthosite, harzburgite, and lherzolite. The general order of crystallization was olivine, orthopyroxene, plagioclase + clinopyroxene, and hornblende. Eleven cyclic units were identified on the basis of evidence for injection of basaltic magma; these can be grouped into three-megacyclic units. Although the intrusion is approximately coeval with Keweenawan magmatism and with emplacement of diabasic dikes in western North America, it is dissimilar in detail to both suites of rocks. Nevertheless, its composition and geophysical setting are consistent with emplacement in an extensional tectonic environment. -from Authors

Original languageEnglish
Pages (from-to)2159-2166
Number of pages8
JournalCanadian Journal of Earth Sciences
Volume32
Issue number12
DOIs
StatePublished - 1995

Fingerprint Dive into the research topics of 'A Grenville-age layered intrusion in the subsurface of west Texas: petrology, petrography, and possible tectonic setting'. Together they form a unique fingerprint.

Cite this