porphyritic's Usage Examples:

with numerous irruptions of volcanic rocks, predominantly porphyritic and dioritic.

in the size of the crystals are called porphyries, and the adjective porphyritic is used to describe them.

It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing.

type of rock that has a porphyritic texture are porphyry, though not all porphyritic rocks are porphyries.

include porphyritic biotite granite, non-porphyritic garnet-bearing biotite granites and smaller occurrences of granite without biotite.

Constituents include porphyritic and non porphyritic rhyolite, obsidian, pitchstone, tuff, and agglomerate.

butte) and nearby Bonelli Peak consist of gray, Proterozoic, porphyritic perthite-quartz-biotite granites and quartz monzonites that are also classified.

is typically a light colored phaneritic (coarse-grained) to porphyritic granitic rock.

Most were breccias, but they did find one porphyritic basalt.

A granitic rock with a porphyritic texture is known as a granite porphyry.

which consist of clinopyroxene and biotite-porphyritic vogesites and minettes, have intruded the K2 gneiss.

False Bay coast just below the old lighthouse at Cape Point, a basic agglomerate plug intrudes course grained porphyritic granite.

Rhomb porphyries are an unusual variety with gray-white porphyritic rhomb shaped phenocrysts embedded in a very.