(redirected from tonalitic)
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 It might be outdated or ideologically biased.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 ?
The results from measured albitites from both mafic and tonalitic magmatic precursors are in accordance with the original values from such protoliths [70] coupled with the influence of a fluid with both a magmatic and seawater origin [69].
Small tonalitic to dioritic bodies (Mill Brook quartz diorite and related plutons) occur along the margins of these large plutons.
The tonalitic suite is exposed to the north and is strongly mylonitised and retrogressed along the fault boundary with formations from the Yaounde Group
Field evidence for this ancient crust is limited to a few remnants of supracrustal and plutonic rocks preserved in the Nuvvuagittuq belt and rare enclaves of tonalitic gneiss.
A second orogeny in the Late Cretaceous culminated with the discordant intrusion of the tonalitic Antioquian batholith.
(2009): Generation of tonalitic and dioritic magmas by coupled partial melting of gabbroic and metasedimentary rocks within the deep crust of the Famantinian Magmatic Arc, Argentina.
The dioritic suite may be significantly older, based on its similarity to varied dioritic, tonalitic, and granitic units dated at ca.
and Portella, P., 2003, U-Pb zircon and monazite geochronology of tonalitic gneiss from Close Lake, Wollaston-Mudjatik Transition Zone, northern Saskatchewan [abstract], Vancouver 2003 (GAC-MAC-SEG meeting), abstract no.
The geologic history of this deposit[4] begins with the intrusion of stocks of tonalitic composition (the Andacollo porphyry, Upper Cretacous) within a layered sequence of andesite and dacites, which induced pervasive hydrothermal alteration (K silicate, quartz sericite) and mineralization (mainly pyrite-chalcopyrite plus some minor quantities of molybdenite, bornite, cubanite and pyrrhotite).