geologic
adj.adj. relating to the study of the Earth's physical structure and the rocks it is made of. It describes things that happen over very long periods of time, like the movement of mountains.
adj. relating to the study of the Earth's physical structure, substance, and history. Typically used to describe processes or time scales involving the Earth's crust and rock formations.
The Grand Canyon shows millions of years of geologic history.
Scientists use geologic mapping to identify areas at high risk for earthquakes or volcanic activity.
The movement of tectonic plates is a slow geologic process that reshapes the continents over hundreds of millions of years.
From geology + -ic, perhaps after French géologique.
Typically used attributively before a noun; 'geological' is a more common variant in British English.