The study of speech sounds in language or a language with reference to their distribution and patterning and to tacit rules governing pronunciation. 2. The sound system of a language: the phonology of English. phoÂ·noÂ·logâ²ic (fÅâ²nÉ-lÅjâ²Ä­k) , phoâ²noÂ·logâ²iÂ·cal (-Ä­-kÉl) adj.
What does a porphyritic texture indicate about the history of an igneous rock? the magma sat and cooled a bit below the Earth's surface, thus giving time for the large crystals to grow, before erupting onto the surface and cooling very quickly
1 Magma is molten rock that flows beneath the earth's surface. 2  Igneous rocks are formed by cooling magma. 3  The location of the formation of the rock, as well as how fast the magma cools will determine the type of igneous rock. 4  Intrusive rocks form from the cooling of magma deep beneath the earths surface. Igneous rocks that form too quickly for crystals to form have what is called a glassy texture. 2  Obsidian is the only glassy igneous rock, and can be identified by its dark color. 3  This looks like dark black glass.