| 释义 |
Definition of tonalite in English: tonalitenoun ˈtɒn(ə)lʌɪt mass nounGeology A coarse-grained plutonic rock consisting chiefly of sodic plagioclase, quartz, and hornblende or other mafic minerals. count noun the margins are invaded by mantle-derived tonalites Example sentencesExamples - These plutons generally contain a variety of rock types, ranging from appinites and diorites through tonalites, granodiorites and rare syenites to ademellites and granites.
- The tonalite is characterized by a strong fabric defined by aligned plagioclase, hornblende and biotite that is interpreted to be a magmatic state deformation fabric formed during emplacement.
- There are enormous intrusions into many of these terrains; layered anorthosites, dyke swarms of basalts, and complexes of tonalite or diorite intrusions also occur.
- The tonalite is gneissic, banded on a decimetre scale, and loaded with discrete mafic enclaves, metasedimentary xenoliths and garnet, feldspar and rutile xenocrysts, such that the body has a migmatitic appearance.
- Permian and Triassic plutonic complexes comprise monzonite, granite, granodiorite or tonalite with minor gabbro and diorite.
Derivatives adjectivetɒnəˈlɪtɪk Geology The Archaean Baidrag complex, composed of tonalitic gneiss, granulite and amphibolite, with minor marble and quartzite, has been interpreted as a microcontinental block. Example sentencesExamples - The Archaean Baidrag complex comprises tonalitic granulites and metasediments.
- Of these, the vast majority comprise late Archaean tonalitic gneiss with various mafic, ultramafic and metasedimentary enclaves, collectively known as ‘grey gneiss’.
- In general, the strain intensity is commonly considerably higher in the granodiorite dykes than in the tonalitic wall-rock gneisses, which probably reflects strain localization into the dykes.
- The granite contains several inliers of tonalitic gneiss, including the Chikwakwa gneisses.
Origin Late 19th century: from Tonale Pass, northern Italy, + -ite1. |