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Relating to or containing a group of light-colored silicate minerals that occur in igneous rocks, including minerals of the feldspathoid group and the minerals quartz, feldspar, and muscovite.

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(of minerals) predominantly composed of feldspars or silicates
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
Some of these exploration targets consist of old shallow pits, caved shafts and historic shallow underground workings in areas with extensive hydrothermal alteration, hosted by major regional structures in a felsic volcanic environment.
The NNR is characterized by mafic and felsic volcanic centers associated with crustal extensions between 15.0 and 16.5 million years old.
The massive sulphide zones occur on the boundary between the felsic porphyry intrusive and the carbonaceous sediments of the Bottle Creek Formation with significant results from EMDD001 shown in Figure 3 Section AA below.
This volcanic succession hosts Au-rich mineralized sub-volcanic felsic bodies yielding slightly younger ages and is covered by Paleocene intermediate lavas with hypabyssal intrusions with ages around 48 Ma.
The Felsic HV family of aluminum electrolytic screw terminal capacitors provides great performances in energy density combined with an ultra-long lifetime.
The property geology contains the contact between Confederation and Balmer Assemblage rock units as well as folded mafic and ultramafic volcanics with mafic and felsic intrusives also present.
The nature and optical character of the major framework constituents and composition of the heavy mineral assemblage suggest that the sediments were largely derived from acidic (felsic) igneous rocks.
Felsic, Mafic and Intermediate are all types of which natural substance?
Dominant classes for GEO arc (predominantly Siluro-Devonian) igneous felsic intrusive, igneous felsic volcanic, (Adaminaby Group) marine sedimentary siliciclastic, sedimentary siliciclastic (includes Siluro-Devonian rift basin, Permo-Triassic Sydney Basin and Cenozoic sediments), and to a lesser extent igneous mafic volcanic (Cenozoic basalts) and quartz-rich arenite to rudite (includes Siluro-Devonian rift basin and Permo-Triassic Sydney Basin sediments).