plutonism

This term is a specialized technical noun used almost exclusively within the history of geology. It describes a specific theoretical framework that emphasizes the role of internal heat and magma in rock formation, contrasting sharply with neptunism, which attributed rock formation to the precipitation of minerals from a primordial ocean.

Because it refers to a specific scientific theory or school of thought, it is treated as an uncountable abstract noun. It is rarely used in modern geological discourse except when discussing the evolution of geological science or the historical debates of the 18th and 19th centuries.