Igneous Processes

Abstract

Igneous processes underlie the formation of igneous rocks. They include melting, melt transport, and melt evolution. This article summarizes each of these processes as they occur in areas of magmatic activity on Earth. Molten rock is generated by partial melting processes including decompression, addition of fluxing components, and conductive heating. Partial melts separate from their residues and ascend by porous flow, diapirism, and dike emplacement. Near the Earth’s surface, magma cools and undergoes partial crystallization processes that lead to cumulate rocks and the eruption of volcanic rocks.