Soil Maps as an Aid to Making Geologic Maps, With an Example from the Culpeper Basin, Virginia

Abstract

I used soil maps to compile a geologic map of the Culpeper basin, an area of 2,200km2, in less than two months. Comparison with two published geologic maps of the area shows that this map is quite accurate and in some instances is an improvement over published maps. Soil maps are especially useful in showing bedrock distribution in heavily vegetated areas where weathering is intense and outcrops sparse. Broad lithologic categories that are readily distinguished include: diabase/basalt, sandstone/shale, conglomerate, and hornfels. Using soil maps is not a substitute for field work, but simply a valuable tool to aid in making geologic maps.