what is a metamorphic rock and how is it formed?
According the Cochise College Geology Website in chapter 7, a metamorphic rock is A rock that has been altered from its original condition by heat and or pressure. Metamorphic rocks are formed deep inside the earth. This can occur with sedimentary, igneous and even old metamorphic rocks. They are subjected to pressure and heat than can flatten and change the shape of the crystals within the rock. (Picture from imperfection.com) (Similar to when you leave a peanut butter and jelly sandwich in your backpack all day when its hot out and it gets smashed by your books). The chemistry of the mineral can even be changed. (Picture from: http://www.glossary.oilfield.slb.com/DisplayImage.cfm?ID=130) After the metamorphic process is complete the rock now falls into one of two categories; foliated or non foliated. Foliated rocks have a layered or banded appearance that is created by exposure to heat and or direct pressure. Non-foliated rocks do not have the distinct layering or banding. Foliated r
