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How to Identify Bedrock on a Hillside

The solid rock that comprises the crust of the Earth is referred to as bedrock. The actual rock types that bedrock is composed of might differ, but generally bedrock will consist of any variety of sedimentary rocks, such as shale and limestone; igneous rocks like granite and diorite; and metamorphic rocks such as slate and greenstone. Bedrock is usually buried beneath up to hundreds of feet of surface rocks and materials. But on hillsides this surface layer is much thinner due to erosion.

Things You'll Need

Geologic maps
Industrial boring drill

Instructions

- 1
  Inspect the surface of the hillside, looking for exposed rock. Identify rock formations that are continuous and appear to be the bottom most layer of all the sediment. The bedrock will appear to be like the exposed skull of the hillside where the "flesh" has been washed away.
- 2
  Consult a surficial geologic map. These are maps with geological interpretations of a given region indicating how far below the surface of an area the bedrock lies.
- 3
  Perform test borings at the hillside site to determine how far below the surface the bedrock lies. As the expression says, "dig until you hit rock bottom." You will be able to identify the bedrock because it will be so hard that you will not be able to dig any further.

Rocks & Minerals