(redirected from tonalites)
Also found in: Dictionary.


McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



a plutonic rock similar in composition to quartzmica diorite. Tonalite is about 33 percent neutral plagioclase, about 16 percent quartz, about 26 percent the colored mineral hornblende, and about 20 percent the colored mineral biotite. Accessory minerals include apatite, zircon, and sphene. Tonalite is used as a building stone, in particular, as an ornamental stone.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
Mentioned in ?
References in periodicals archive ?
Kyanite-garnet bearing tonalite, which is reported for first time from the Chilas complex in Kiner Gah area, indicates crustal contamination and amphibolite grade metamorphism.
Les tonalites, les rythmes et les tempos contribuent a produire le << mot d'ordre >> de la campagne de facon plus festive, agreable ainsi qu'a suscite une ambiance globale.
Notre etude aboutit au tableau suivant, qui reunit les sections, themes, topiques, mesures et tonalites et que nous allons expliciter ci-apres (voir la fig.
Moreover, the low-grade metamorphic conditions during Chanic deformation and the presence of pre- and syn-orogenic granitoids (Carrizalito tonalite), early Carboniferous in age, indicate that this area forms part of the hinterland of the Chanic orogen.
Lithologic varieties observed in the stock include a compositional range from tonalites to monzogranite, with enclaves of melanocratic diorites (Fig.
In general, pyroxene-bearing rocks, granites, and granodiorites have higher magnetic susceptibilities than metavolcanic and metasedimentary rocks (except iron formation) and associated tonalites and diatexites (Pilkington and Percival 1999, 2001; Leclair et al.
In the zone amphibolites, gneisses, tonalites and mica schists alternate frequently.
On Reindeer Lake plutons range in composition from diorite to granite, although quartz diorites, tonalites and granodiorites predominate.