Which term is associated with a gray, fine-grained volcanic rock containing plagioclase and possibly pyroxene?

Andesite is a gray, fine-grained volcanic rock that is predominantly composed of plagioclase feldspar, along with possible amounts of pyroxene and other minerals. This rock type typically forms from the partial melting of the Earth's mantle and is often associated with convergent tectonic plate boundaries, particularly in subduction zones where oceanic crust meets continental crust.

The composition of andesite often places it in the intermediate range between the more silica-rich rocks (like granite) and more mafic rocks (like basalt), thus making it an important rock type for understanding volcanic activity and the geological processes involved in the formation of the Earth's crust. The presence of plagioclase in andesite gives it its characteristic gray color and fine-grained texture, distinguishing it from other rock types.

In contrast, peridotite is an ultramafic rock primarily made up of olivine and pyroxene, typically found in the Earth's mantle rather than on the surface as a volcanic rock. Granite is a coarse-grained, intrusive igneous rock rich in quartz and feldspar, formed from the slow crystallization of magma beneath the Earth's surface. Gabbro, like basalt, is a mafic rock but is coarse-grained and typically found