unmetamorphosed
Unmetamorphosed refers to geological materials, most commonly rocks, that have not undergone metamorphism. Metamorphism is a process in which existing rocks are transformed by heat, pressure, or chemical reactions without melting. Therefore, unmetamorphosed rocks retain the original mineralogy and texture they possessed when they were formed.
In the context of sedimentary rocks, unmetamorphosed means they have not been subjected to the conditions that
Similarly, igneous rocks are considered unmetamorphosed if they have not been altered by subsequent geological processes.