What rock compositions (such as basalt or granite) are the most common in the Cascade Range Volcanoes.?

Answer 1

As a geology Ph.D. student, I'm going to second what rocklady says. The main rocks are andesite, rhyolite and dacite, plus some rhyodacites. The people who say granite are in error, granite has the same chemical composition as rhyolite, but much larger crystals. It cools slowly underground, as an "intrusive" igneous rock. Igneous rocks that erupt at the surface as volcanic rocks have smaller crystals, and are termed "extrusive" igneous rocks. They might have the same minerals in them as intrusive rocks, but they have different names because of the different crystal sizes ("grain-size"). For example, basalt is extrusive and fine-grained, whereas gabbro is intrusive and coarse-grained. The same goes for granite (intrusive and coarse-grained) and rhyolite (extrusive and fine-grained). Dacites and rhyodacites have similar chemical and mineral compositions to rhyolites, whereas andesites are mid-way in composition between rhyolite and basalt. Probably there are granites forming deep in the crust below the Cascade volcanoes though, where they can cool slowly and form large crystals. We can say this by looking at the Sierra Nevada mountains: these mountains represent the eroded "roots" of an ancient volcanic mountain chain, and are composed of granites and similar rocks.

Answer 2

Granite makes up a huge amount of the Cascade Range, therefore, its volcanoes.

Answer 3

Typical rock composition is andesite, however other rock types range from basalt to dacite to rhyolite.

Check out the webiste I've posted below.

Answer 4

granite do u know why because because the growth of granite is very slow and there r many granite rocks under the ground so because of low process it becomes tight and hot and they r more common ok know tell me is this the best answer if it is so please click best answer i am in grade 8