Glacial Drift
Glacial drift is a special type of sedimentary deposit that contains many different rock types that were formed outside of Kentucky. During ice ages, numerous igneous and metamorphic rocks from Canada and the northeastern United States were transported by glaciers and deposited by meltwater streams in northern Kentucky in Trimble, Carroll, Gallatin, Boone, Kenton, Campbell, Pendleton, and Bracken Counties. These rocks (called glacial erratics because they were deposited from elsewhere) are composed of igneous rocks such as granites and basalts, metamorphic rocks such as schist, phyllites, and gneisses, and sedimentary rocks such as limestone and siltstone. It is remotely possible that some gold and diamonds may also be associated with these glacial erratics.