GEOL 1001 : GEOLOGY NOTES Midterm 2
Document Summary
Mud-sized particles in thin layers that are called lamina. Predominant mineral= quartz: conglomerate and breccia. Both are composed of particles greater than 2 millimeters in diameter. Breccia is composed of mainly large angular particles: texture. Angularity of grains: chemical rocks, limestone, most abundant chemical rock, composed chiefly of the mineral calcite, marine biochemical limestones form as coral, dolostone, typically formed secondarily from limestone. Hydrothermal metamorphism: hot mineral rich water rises to the seafloor, cold water perculates in to the hot newly forms seafloor, black smoker spewing hot mineral rich seawater. Regional metamorphism: produces the greatest quantity of metamorphic rock, associated with mountain building. Regional metamorphism and metamorphic grade: mineral isograds (zones of change, index minerals reflect pressure and temperature conditions, groups of two or three index minerals form an isograd, coal is a metamorphic rock produced by burial of organic material. The quality(rank) of coal depends on the grade of metamorphism. Angular- tilted rocks are overlain by flat lying rocks.