agmatite

agmatite

[′ag·mə‚tīt]
(petrology)
A migmatite that contains xenoliths.
Fragmental plutonic rock with granitic cement.
References in periodicals archive ?
In order of decreasing age they are (1) agmatite containing blocks of host rock in a coarse-grained igneous matrix, (2) felsite, rhyolite porphyry, and microgranite, (3) layered and massive gabbro, (4) medium- to coarse-grained amphibolebiotite granite, (5) heterogeneous mafic rocks with a generally dioritic to tonalitic matrix containing schliers and blocks ranging from layered gabbro, to monzonitic, syenitic and granitic varieties.
Although some small-scale contacts of the batholith with its host rocks appear knife-sharp and generally conformable, agmatite (Fig.
The top of the section, northwest of Tilting, consists of coarse-grained, unfoliated plagioclase-hornblende rocks which grade to quartz dioritic agmatite containing metre-scale fragments of layered mafic rocks.
Coarse-grained granite of the Fogo Island Batholith occurs as an east-west belt across the northern part of the island, partially separated into three lobes by narrow belts of hornfelsed host rocks, agmatite, and sheets of felsite.