Outcrops

Part of speech: noun

Definitions

1. Geological formations where layers of rock are prominently visible above ground
2. Regions where rocks pierce through the earth's surface due to erosion or other geological processes
3. Natural exposures of bedrock or ancient deposits visible at the earth's surface

Etymology: Outcrop is built from two plain English parts: "out," meaning outside or emerging, and "crop," an old word for the top or head of something, as in a plant's crop or a bird's crop. A crop-top, in this sense, is the part of a plant that shows above the ground. Geologists took that image and applied it to bedrock: a layer of rock that rises through the soil and shows at the surface looks like the top of something pushing up into view. The sense of "crop" meaning the tops of growing things is much older than its use for harvests, and the verb "to crop" originally meant to cut off the top or tips of something, such as a plant's shoots or an animal's ears. Outcrop therefore joins an image of growth with an image of something breaking the surface, and the noun's meaning has stayed close to that physical picture.