Still more common is the occurrence of sheared, foliated or schistose forms of gabbro.
Anorthite is an essential constituent of many basic igneous rocks, such as gabbro and basalt, also of some meteoric stones.
A soil of very close texture, the gabbro, is found, most largely in the north-east.
These are caused either by old intrusions of diabase and gabbro which have undergone modifications, or by later ones of dolerite.
gabbro, gab′ro, n. a rock composed of feldspar and diallage—also Euphotide.
These volcanic materials are pierced by serpentine, gabbro and granite.
Peridotite and gabbro form much of the eastern peninsula (Banggai).
gabbro, a typical basic rock, corresponds to basalt in chemical composition.
Lithologically they are crystalline schists, together with granite, diorite, gabbro and other igneous rocks.
The gneisses appear to be due in many cases to the crushing and shearing of deep-seated igneous rocks, such as granite and gabbro.