变质岩形成时岩石(沉积岩、火成岩或以前的变质岩)在高压力和/或温度。压力和温度力的原子形成新矿物,从而一种新的岩石。它不是必要的支离破碎,但岩石,而演变成一个新的国家在应对压力和温度。好的岩石学家通常可以确定什么样的母岩metamorphed到什么程度,但有时很难做到识别的区别如风化板岩和页岩或花岗岩和片麻岩。然而,过程形成的岩石和代表不同的流程不同。程度的变质作用称为变质相。[![变质阶段][1]][1]* 1,蓝片岩相2,榴辉岩相3 Prehnite-pumpellyite-facies 4,绿色片岩相5 Amphibolite-facies 6,麻粒岩相7,沸石相8日Albite-epidote-hornfels相9日Hornblende-hornfels相10,Pyroxene-hornfels相11日透长岩相*举个例子,如果一个岩石暴露在非常高的压力,但只有几百摄氏度,蓝片岩组成,其间形成角岩在400美元- 800 ^ oC但低压。火成岩形成晶体融化变硬时,从沉积物形成沉积岩。较低程度的变质,保存原始岩石的特性。 E.g. you can see ripples and layering in slates or deformed structures from the source rock, but at higher degrees of metamorpism it's increasingly difficult to imagine how the parent material looked like. All rocks weather if exposed to water and air, and weathered material is transported by rivers to oceans where sandstone can be formed from the sand at the beach and shale from the finer sediments further away from the coast. Igneous rocks can be formed as hot magma intrudes the crust and slowly cools down and minerals are formed or form lava at volcanoes. You can read more about the rock cycle e.g. [here][2] to better understand the types of rocks and how they are formed from each other. [1]: https://i.stack.imgur.com/wcisW.png [2]: http://www.cotf.edu/ete/modules/msese/earthsysflr/rock.html