Subscribe to RSS Metamorphic Rock Formation Transforming Igneous RocksMetamorphic Rock Formation from igneous rocks is caused by heat and pressure. This is most often the result of mountain building. Plate Tectonics and Mountain BuildingWhen the plates of the earth collide, they squeeze the rocks at...
Metamorphic rocksare formed when existing rocks (igneous, sedimentary, or even older metamorphic rocks) are subjected to heat, pressure, and chemically active fluids, causing them to change (metamorphose) without melting. These conditions cause the minerals in the original rock to recrystallize and re...
The term included both consolidated and unconsolidated material. Sedimentary rocks may be classified as (a) terrigenous (breakdown of pre-existing rock), (b) organic (produced by organic process), (c) chemical (precipitation from water), (d) volc ......
The temperature that the rock is subjected to is a key variable in controlling thetype of metamorphismthat takes place. As we learned in the context of igneous rocks, mineral stability is a function of temperature, pressure, and the presence of fluids (especially water). All minerals are stabl...
In contrast to the formation of igneous rocks, metamorphic rocks do not crystallize from a silicate melt, although high-temperature metamorphism can lead to partial melting of the host rock. Because metamorphism represents a response to changing physical conditions, those regions of Earth’s surface ...
The process by which a metamorphic rock passes from conditions of low temperature to higher temperature conditions is known as "prograde metamorphism", whereas that by which a rock passes from high temperatures to lower ones (perhaps on its way back to the surface) is termed "retrogression"...
A rock undergoing metamorphism remains a solid rock during the process. Rocks do not melt during most conditions of metamorphism. At the highest grade of metamorphism, rocks begin to partially melt, at which point the boundary of metamorphic conditions is surpassed and the igneous part of the roc...
Goldsmith proposed, in 1959, the name granofels for such a rock type. Schistosity: A type of foliation produced by metamorphic processe, characterised by the preferred orientation of inequant mineral grains or grain aggregates. A schistosity is said to be well developed if inequant mineral ...
type of rock, the other two being igneous and sedimentary. Because of how they are formed, metamorphic rocks constitute a great deal of the bedrock in Earth's crust. Many precious materials, such as marble and many types of gemstones, including diamonds, are formed by the metamorphic process...
The composition of the rock resulting from a metamorphic process depends essentially on the original composition, the conditions of temperature and pressure, and the presence and activity of fluids. The metamorphic processes range from recrystallization, which involves the increase in size and/or the ...