Glacial drift is a special type of sedimentary deposit that has brought many different rock types to Kentucky that were formed outside of Kentucky. During the previous 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 glacial erratics 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. There is a wide assortment of igneous and metamorphic rocks in these deposits that are not normally found in Kentucky. It is remotely possible that some gold and diamonds may also be associated with these glacial erratics.