Karst and Sinkholes

Other karst features

Enlarged fracture – Also called joints, enlarged fractures appear as large cracks in the ground that become narrower with depth.

Cave – A natural cavity, large enough to be entered, that is connected to subsurface passages in bedrock.

Pavement – Extensive bare areas of exposed bedrock surfaces with many enlarged fractures or sinkhole features.

Mine feature – A man-made shaft, tunnel, cave, hole, or other feature created for mining purposes.

Swallet – A place where surface or stormwater drainage disappears underground.

Spring/seep – Intermittent or permanent seepage of water from ground surface or bedrock outcrop or karst area. (Learn more about springs.)

Karst fen – Marsh formed by plants overgrowing a karst lake or seepage area.

Karst pond – Closed depression in a karst area containing standing water.