Chapter 4 - Geomorphology - Karst Features Flashcards
Karst
The topography of a region which is underlain by limestone, dolomite, gypsum, or other rocks which can be affected by dissolution
Terra Rossa
A red clayey (CL-CH) soil found mantling the ground surface and extending into joints or fractures resulting from surface or near surface solution, usually found on moderate to gentle slopes
Lapies
Grooved or fluted surface resulting from the solution of limestone at or near the surface in an area of high relief. The grooves range in width from a few millimeters to more than a meter in width and commonly result in knifelike ridges.
Sinkholes
A circular depression that is commonly funnel-shaped and can be a few feet to a hundred feet in diameter. This is the most commonly observed feature of karst terrain.
Origin of Sinkholes
- Solution of the rock beneath the soil (a doline)
- The collapse of the rock over an underground cavity (a collapse sink)
Compound Sinkhole
In an area riddled with sinkholes, as the sinkholes enlarge with time they may expand and combine with adjoining sinkholes
Sinkhole Ponds or Karst Lakes
A pond or lake resulting from the clogging by clay of a doline sinkhole that perches water above the water table.
Swallow Holes
A hole in the bottom of a sinkhole which allows surface water runoff or streams to flow into the subsurface cavities
Karst Window
A hole in the ground in which one can observe an underground stream flowing from one carver to another. A whole in a cavern which breaks the surface.
Uvala
An elongated karst windown that has occurred by the collapse of an extensive portion of a subsurface waterway. These features can extend from 1000 feet to a mile or more.
Polje
A sinkhole formed by solutional modification of the rock (similar to a doline) in a previously faulted or folded structure. This feature can be 30 miles or more in length.
Solution-Subsidence Trough
A non-tectonic feature, up to 10 miles in length, resulting from concurrent subsidence and solution along joints or faults
Sinkhole or Karst Plain
A limestone plain exhibiting sieve-like characteristics resulting from numerous sinkholes intercepting any surface waters and diverting them to subsurface channels
Sinking Creeks
Any surface creek or stream which disappears underground in karst terrain; many disappear in a swallow hole
Sink
The point at which a sinking creek ends, often in an observable swallow hole
Blind Valley
A valley that ends at a swallow hole due to a prolonged period of upstream erosion above the sinkhole
Solution Valley or Karst Valley
A transitional feature between surface and subsurface drainage in and area of clastic rocks. A special type of blind valley.
Natural Tunnels and Bridges
Features produced by the underground flow of water in karst terrain. When the tunnel sections collapse leaving only small segments, bridges are formed.
Hum
Isolated hill remnants due to erosion by solution in karst terrain
Cavern
Large caves that may extend in any direction, have one or several levels, and are created by solution of limestone along joints and bedding planes
Travertine
A deposit of calcium carbonate precipitate that can be found in limestone caverns coating the cavern walls, floors, and ceilings
Dripstone
The travertine deposits that result from the calcium carbonate-rich water dripping from the ceiling of a cave or cavern. Stalactites are the downward protrusion of these deposits and stalagmites are the upward protrusion
Helictite
An irregular twiglike deposit forms in a cavern where there is not enough water to form drips but the surface remains damp or the water comes from a tiny hole or tube within the deposit and the water flows out the end
