The Rocks of the Andes Mountains Coursework Example | Topics and Well Written Essays - 2000 words

The Rocks of the Andes Mountains - Coursework Example The andesite is not equivalently comprised of the diorite or plutonic for the reason that these two are not intermediate in their composition as is an andesite. Additionally, diorites are intrusive igneous rocks that mostly comprise of plagioclase feldspar, but to a lower degree. As such, there is no equivalence in the rocks since the character of andesite is that it results from magma melting and assimilation to the surface, which is not the case for the diorites. Thus, it tends to be higher in silicon than the diorites (Cull 74-78).The formation of andesite in the Andes Mountain region is often defined by the melting and assimilation of the rock fragments by the rising magma to the surface. This crustal extension and magmatic activity that occurs during the melting and assimilation process of the rocks make the rocks in the region to predominantly change to andesitic nature due to a change in their mineral composition. Largely, this process can be affiliated to the main geologic ev ent referred to as the Andean Orogeny, which was mostly characterized by the subduction of the ocean crust (McCann 125-129). The process of magma differentiation may be attributed to the creation of various compositions of rocks within a single magma chamber. By definition, magma differentiation may be referred to as the process of causing the composition of magma to change i.e. the process by which igneous rocks that are chemically different forming from the initial magma.