1. a hard layer of rock that overlies softer rock or sediment
Usage: geology
2. a resistant rock formation that forms the top of a mesa, butte, or plateau
Usage: geology

Examples

• The limestone caprock protected the softer sandstone beneath from erosion.
• Geologists studied the caprock formation at the top of the mesa.
• Without the caprock layer, the entire hillside would have eroded away long ago.
• The caprock consists of a hard quartzite that resists weathering.
• Oil deposits were often found trapped beneath the impermeable caprock.
• The distinctive flat top of the butte is formed by a thick caprock layer.