Geology Archives | Page 8 of 9

Andesite Rock Composition and Formation

Andesite is an intermediate volcanic or extrusive igneous rock. Intermediate rocks are moderate in silica (52-63 wt.%), mafic, and felsic

Andesitic magma or lava has an intermediate composition with moderate silica content between 57 and 63 wt. %. Its composition

Magma refers to hot, molten, or semi-molten rocks under the Earth’s surface, while lava refers to magma that makes it

Ultramafic is a common term in geology, GEOsciences, Earth sciences, or geography. It is commonly used in igneous rocks, their

The coarse-grained or phaneritic texture is an igneous rock texture in which you can see and distinguish individual minerals without

Carbonatites are uncommon and strange igneous rocks with more than 50% carbonate minerals by volume and less than 20 wt.

To understand intermediate magmas and lavas well and their characteristics, you need to know their composition lies between mafic and

Insolation or thermal expansion weathering refers to rock breakdown that happens when rocks contract and expand. Some authors call it

Wetting and drying or slaking is an example of mechanical or physical weathering. It occurs when rocks exposed to the

Dunite is an ultramafic plutonic or intrusive igneous rock in which olivine exceeds 90% by volume. Ultramafic means it has