Wisconsin Geological and Natural History Survey home  
Research programs at the Survey
Survey news and information
Survey publications
Survey staff
About the Survey
For more information
Other earth-science sites


Examples of karst

Click on a photograph to see a larger version.

sinkhole--vernon Co. A topographic depression (unless filled) in which bedrock is dissolved or collapsed. Sinkholes may be open, covered, buried, or partially filled with soil, field stones, vegetation, weathered bedrock, water, or other miscellaneous debris. Sinkholes are usually circular, funnel-shaped, or elongated. Sinkhole dimensions vary by region. Wisconsin sinkholes generally range between 20 to 30 feet in diameter and 4 to 10 feet deep, although some can be wider and/or deeper. The sinkhole pictured here is in Vernon County, Wisconsin.

Enlarged fracture
enlarged fracture--brown co. Solution enlarged or widened bedrock fracture that usually narrows with depth. The enlarged fracture, also called a joint, shown here is from Brown County.

Fracture trace
fracture trace--brown co.A linear feature, including stream segment, vegetative trend, and soil tonal alignment. This bedrock fracture, or vegetation lineament, is near Bayshore Park, Brown County.

images of a cave entrance cave entrance--door county sinkhole--vernon county Wequiock cave entrance another view of Wequiock Cave entrance A natural cavity, large enough to be entered, that is connected to subsurface passages in bedrock. Pictured top row left is the entrance to a cave in Door County; top row right, a sinkhole that leads to a cave in Monroe County. bottom row, two views of the entrance to Wequiock Cave in Brown County, Wisconsin.

small swallet A place where surface or stormwater drainage disappears underground. The swallet shown here is in Brown County.

Mine feature
mine feature--a shaft entranceA man-made shaft, tunnel, cave, hole, or other feature created for mining purposes. This mine feature is a shaft entrance rock pile in Iowa County.

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

Intermittent or permanent seepage of water from ground surface or bedrock outcrop or karst area.

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

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

Back to Sinkholes page.