Petrogenesis of anorthosite pdf

2019-11-12 16:04

Petrogenesis of a MidProterozoic Granite (AMCG) Complex: Isotopic and Chemical Evidence from theThe first four types of anorthosite are thought to have formed by crystallization of residual melts formed by fractional crystallization from dry melts, because of their anhydrous mafic mineralogy, whereas the hydrous anorthosites are believed to form by anatexis of plagioclaserich rocks in the presence of an H 2 Orich fluid phase (Oliver, 1977; Fershtater et al. , 1998; Selbekk et al. , 2000). petrogenesis of anorthosite pdf

Cawthorn, R. G. and Collerson, K. D. 1974. The Recalculation of pyroxene end member parameters and the estimation of ferrous and ferric iron content

The origin of anorthosite and associated igneous gabbronorite and ferrodiorite was investigated through detailed study of a typical massiftype anorthosite complex from Gruber, Central Dronning Maud Land, East Antarctica. and Petrogenesis of Perinthatta Anorthosite, Northern Kerala is a genuine record of research work done by me under the supervision of Dr. C. G. Nambiar, Reader, Department of Marine Geology and Geophysics, School of Marine Sciences, Cochin petrogenesis of anorthosite pdf In this paper, based on detailed field studies and microscopic observations, combined with the major and trace element characteristics of plagioclase, apatite, titanite, ilmenite, and prehnite, we decipher the petrogenesis, formation mechanism and formation condition of the rare scheelitebearing anorthosite in the Zhuxi giant scheelite deposit.

In addition to this fundamental aspect of the anorthosite problem (see Bowen, 1917; Scoates, 2000), the petrogenesis of massif anorthosites was apparently restricted in time and space. petrogenesis of anorthosite pdf Petrographically, anorthosite is composed totally of plagioclase megacrysts with subordinate interstitial amount of augite, enstatite, and amphibole, biotite, Kfeldspar, and quartz. Accessories anorthosite (A). Note the presence of brightcoloured sulphides interstitial to the Crspinel crystals. b Photograph of polished hand specimen through the Unit 78 boundary illustrating peridotite (P), main seam chromitite (M), anorthosite (A), subsidiary seam chromitite (S) and troctolite (T). The height of the section shown is 8 cm. petrogenesis of the Pipestone Lake anorthosite complex (PLAC). Detailed stratigraphic mapping in the lower and middle parts of the complex revealed the presence of cyclic units that typically consist of a lower

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