This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (December 2009)

Protolith refers to the precursor lithology of a metamorphic rock.

For example, the protolith of a slate is a shale or mudstone. Metamorphic rocks can be derived from any other rock and thus have a wide variety of protoliths. Identifying a protolith is a major aim of metamorphic geology.

Sedimentary rocks have no protolith because they are made of sediment. However, the source of the sediment is termed its provenance.

Igneous rocks have no protolith because they form from magma.

This article related to petrology is a stub. You can help Wikipedia by expanding it. v • d • e