GEOL 104 Study Guide - Midterm Guide: Pegmatite, Feldspar, Volcanic Glass

• School: Queen's University
• Department: Geological Sciences and Geological Engineering
• Course: GEOL 104
• Professor: Daniel Layton- Matthews

Document Summary

Rapid rate of cooling of lava / magma. May contain vesicles (holes from gas bubbles and thus rocks that contain them have a vesicular texture. Phaneritic texture (can be seen w/ the naked eye) coarse grained. Large crystals (phenocrysts) embedded in a matrix of smaller crystals (groundmass) Two distinct sized minerals, some big ones some small ones. Distributing prohibited | downloaded by scarlet choi (choia980806@gmail. com) lomoar cpsd| 1578061. Eruption and explosion occur, but cools so quickly that minerals couldn"t form. From in late stages of crystallization of granite magmas. Common crystals of quartz, felspar and muscovite are abnormally large minerals get so big that you can see them from far away. The more volatiles in the solution in the magma, the more violent the eruption. Igneous rocks are classified by their texture and mineral composition. Various igneous textures result from different cooling histories. Two rocks may have similar compositions but different textures, thus different names i. e. granite - rhyolite.