01:460:100 Lecture Notes - Lecture 5: Gabbro, Andesite, Komatiite

• School: Rutgers University
• Department: Geological Sciences
• Course: 01:460:100
• Professor: browning

Document Summary

Igneous changes in solid state, melted, ignis(fire) , molten rock material, always inside the earth. Interlocked minerals when lava cooled with no orientation, cooled inside earth. Batholith: 100km^2 at least (mount rushmore/sierra nevada) Sill- sheet-like igneous rock parallel to exsisting layering. Dike- sheet like cut across exsisting layering. Can be classified by texture and composition. Palisades sill: texture- phaneritic (large enough to be seen with unaided eye), slow cooling. Aphanitic- too small to be seen by the unaided eye. Glass- no crystals, fast cooling: texture tells us about the cooling rate of the rock, fast cooling- less coarse, two distinct crystal sizes in a rock porphyry. Magma chamber moves up after cooling at a slow rate. Aphanitic rhyolite andesite basalt-ocean base komatiite- not hot enough. Mineral comp. quartz/orthoclase amphibole/na plagioclase pyroxene/calcium pero olivine/proxene. Geothermal gradient- change in temperature with depth in the earth. Basalt- liquid melting point higher than temperature of gg.