Karst TopographyBy Taylor Pepper

What is Karst?Early on, Karst landscapes look like any other generally flat plane, but with cracks sizeable enough to drain and store water from the constant rainfalls and a top layer of soluble rock like limestone or dolomite

Karst terrain is generally barren, rocky ground lacking in surface streams or rivers with caves, sinkholes, lapies, pepino hills, land bridges, and underground streams/ rivers

One example of Karst landscape is the Tsingy de Ankarana (top image) which shows a “forest” of limestone blades remaining after water dissolved the rest of the Jurassic stone away

Another example is Carlsbad Caverns in New Mexico (bottom image) which is a large system of caves with massive limestone deposits and scattered underground springs

How Are Karst Landscapes Formed?Elements that promote Karst landscapes:

Dense, jointed limestone (or other soluble rock)

near the surface

Moderate to heavy rainfall

Openings to allow good groundwater circulation

The water flowing into the vertical cracks, and

sinkholes, at the surface down to the openings

underground circulate long enough to form cave

systems or underground water channels

Sinkholes are formed by the tops of cave systems

collapsing due to opening so close to the surface

ThermokarstThermokarst- configuration of the land due to the melting of ground

ice in a region with permafrost

The size and nature of the features depend solely on how much ice is

in the area and the nature of that ice

The widespread effects of thermokarst show the region is warming in

temperature, while a localized situation can be due to traffic of some

sort or construction efforts, deforestation, or agriculture

Features created by melting dead glacial ice is not considered

thermokarst

FluviokarstFluviokarst- evidence of tributary surface streams that

lead to stream beds underground where the drainage

occurs

Ex. A normal stream valley that gradually deepens its

channel until it accesses underground dolomite deposits,

which water is lost in the fractures to create underground

cave systems

Surface becomes a "blind valley", or polje, which are long

basins with flat surfaces surrounded by steep cliff sides, or

a "dry valley" where no more channels are created

Floor of valley full of sinkholes and limestone residue

Salt KarstSalt Karst- a solution phenomena that occurs in rock salt

under the effect of groundwater

Rock salt is actually more soluble than the calcite

dissolved in Karst topography, it is impervious because the

solution can only happens on the outside surface

The brine created from the dissolved salt must be carried

away by groundwater in order for more solution to occur

The topographical features are formed depending solely

on the thickness of the rock body

These shallow features can be created on flat landforms

with thick salt crusts by the draining of water down to the

water table

Doline KarstDoline Karst- usually rolling plains with few surface

streams and no valleys

Surface covered by a multitude of sinkholes of different

sizes that can connect to create valley sinks, and this is

caused by the dissolution of the bedrock at fractures,

collapsing cave roofs, or soil loss

An arched void forms and stretches to the surface to

form sinkholes

Pavement KarstPavement Karst- bare carbonate rocks exposed to

weathering

Usually occurs because of glaciation, where ice scrapes

off soil and other materials to expose the bedrock

underneath

Occurs in higher altitudes and alpine areas where

glacial activity is common

The solution also weathering of the dolomite is usually

due to direct rainfall on the rock and meltwater from

snowpacks

Karren, features of Pavement Karst, consists of

solutionally widened joints, small runnels, small

residual pinnacles, and other features

Cone and Tower KarstCone and Tower Karst- thick limestone deposits are

separated by grids of fractures

Common in tropical areas

The solution produces rigid edges of the limestone

towers, which divide them into separate pieces

The water dissolving the edges drains into the

subsurface, preventing the area from becoming a valley

system

Cones are created when the water affecting the deposit

creates a conic shape out of the deposit

In other situations, gorges reach a sort of base level

where it begins widening, allowing the features to stick

out vertically throughout the plain

References1. Encyclopædia Britannica, Inc. "Karst.” Encyclopædia Britannica Online, Web. <https://www.britannica.com/science/karst-geology>.

Accessed 14 Sept. 2016.

2. Maurits & Marjol. “Tsingy de Ankarana.” Flickr, Image. <http://www.wondermondo.com/Madagascar.htm>. Accessed 21 Sept. 2016.

3. National Park Service. “Carlsbad Caverns, NM.” The Physical Environment, Image. <http://www.earthonlinemedia.com/ebooks/tpe_3e/mass_movement_weathering/karst_landscapes.html>. Accessed on 14 Sept. 2016.

4. Encyclopædia Britannica, Inc. “Cross Section of a Cave.” Encyclopædia Britannica Online, Image. <https://www.britannica.com/science/karst-geology>. Accessed 21 Sept. 2016.

5. Encyclopædia Britannica Inc. "Thermokarst.” Encyclopædia Britannica Online, Web. <https://www.britannica.com/science/thermokarst>. Accessed 14 Oct. 2016.

6. Anthony, Katey Walter. “Arctic Lakes.” UAF, Image. <http://news.uaf.edu/arctic_lakes_july2014/>. Accessed 14 Oct. 2016.

7. “Salt Karst.” Tamriel-Rebuilt, Image. <http://tamriel-rebuilt.org/forum/region-deshaan-plains-concepts-discussion>. Accessed 17 Oct. 2016.

8. "Classic Fluviokarst." Cave Archaeology, Image. <http://cavearchaeology.weebly.com/karst-geomorphology.html>. Accessed 17 Oct. 2016.

References Contd.1. Encyclopædia Britannica Inc. "Cave." Encyclopædia Britannica Online, Web.

<https://www.britannica.com/science/cave/Solution-cave-features>. Accessed 17 Oct. 2016.

2. Homer, Lloyd. "Dolines." Science Learning, Image. <http://sciencelearn.org.nz/Contexts/A-Fizzy-Rock/Sci-Media/Images/Dolines>.

Accessed 17 Oct. 2016.

3. Chensiyuan. "Cone Karst." Wikipedia Creative Commons, Image. <http://www.goodearthgraphics.com/virtcave/karst/karst.html>.

Accessed 17 Oct. 2016.

4. "Tower Karst." Environmental Hazards in Karst Landscapes, Image.

<http://people.uwec.edu/jolhm/eh/below/Matt%20Below%20-%20GEOG%20361-home.htm>. Accessed 17 Oct. 2016.

5. Lupin. "Limestone Pavement Above Malham Cove." Wikimedia Commons, Image.

<https://commons.m.wikimedia.org/wiki/File:Limestone_pavement_above_Malham_Cove.jpg#mw-jump-to-license>.