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
Plutonic rocks, which cool slowly underground, have large crystals because the crystals had enough time to grow to a large size. Volcanic rocks, which cool quickly above ground, have small crystals because the crystals did not have enough time to grow very large. The type of igneous rock is also dependent on its composition (the elements that are present). There are many different compositions of magma and lava. Fortunately, most igneous rocks are one of three basic compositions: 1  Felsic igneous rocks contain relatively high amounts of silicon, sodium, aluminum, potassium (Si, Na, Al, and K) and relatively low amounts of iron, magnesium, and calcium (Fe, Mg, Ca).