the bikilal layered gabbro-complex is composed of zones/layers of olivine/ pyroxene gabbro and hornblende gabbro. within the hornblende gabbro, repeated lens-like thin and elongated bodies of hornblendite are found intimately associated with massive and disseminated ilmenite-magnetite bodies, in places with apatite. petrological examination of the hornblende gabbro shows 50-55% hornblende, 40-4...

The Pelona, Orocopia, and Rand Schists and the schists of Portal Ridge and Sierra de Salinas constitute a high–pressure-temperature terrane that was accreted beneath North American basement in Late Cretaceous–earliest Tertiary time. The schists crop out in a belt extending from the southern Coast Ranges through the Mojave Desert, central Transverse Ranges, southeastern California, and southwest...

late neoproterozoic-early cambrian schists have been occurred in southwest of zanjan city from the soltanieh belt. the soltanieh belt in northwest of iran is uplifted basement of precambrian-paleozoic in main central iran zone and includes outcrops of precambrian, paleozoic and mesozoic formations. late neoproterozoic-early cambrian schists, the oldest stratigraphy unit in the region, consist o...

Kaersutitic amphiboles foundwithin a subset of theMartianmeteorites have lowwater contents and variably heavy hydrogen isotope compositions. In order to assess if impact shock-induced devolatilization and hydrogen isotope fractionation were determining factors in thesewater and isotopic characteristics of theMartian kaersutites, we conducted impact shock experiments on samples ofGoreMountain am...

During the COUIX of I :50 000 scale regional mapping in the Northern Selkirk Mountains (NTS 082M) various granitic rocks were sampled for U-Pb geochronology. This report presents new U-Pb data, interpreted ages, and the implications of these results for hvo such samples from the Selkirk Allochthon: the Downie Creek otihogneiss, and the Goldstream Pluto”. The Downie Creek orthogneiss consists of...

INTRODUCTION Precambrian rocks in the Tusas Mountains range from nearly monomineralic quartzite, in which the principal result of metamorphism has been simple recrystallization, through locally metasomatized schist and gneiss profoundly modified by potash-rich fluids during the intrusion of pegmatite. Texturally, the rocks range from schist and phyllite containing penetrative and pervasive clea...

in the asemi-gawa area of intermediate high-pressure and low-temperature sanbagawa metamorphic belt in central shikoku, japan, piemontite-quartz schists are common in which cation exchange between piemontite and garnet has been studied. piemontite in contact with garnet usually contains two zones in which core is enriched in mn3+ and surrounded by a rim rich in fe3+. garnet is ca-fe-bearing spe...

We present thermodynamic estimates of pressures, temperatures, and volatile activities in vailably deformed, gabbroic to granitic, Cretaceous (115-100 Ma) batholithic and framework rocks of the Tehachapi Mountains, southernmost Sierra Nevada, California. A1 contents of hornblende in granitoids imply igneous emplacement at --8 kbar in the southernmost Tehachapi Mountains, with lower pressures (3...