Module 8 Karst Topography

speleothem

A general term for all cave formations

speleologist

A scientist who studies caves

Initial stage of development

a karst area has just a few scattered sinkholes and caves

climate that discourages karst topography

cold

type of weathering that produces karst topography

dissolution

"losing" or "sinking" stream

flows over land and then disappears underground into openings created by the acidic dissolution of rock. The water does not always resurface.

stalactites

hang "titely" on the cieling

sinkhole

holes or depressions in the ground that form when the underlying soil, bedrock, or water is removed. In karst environments sinkholes are formed when limestone rock under the surface is dissolved away by acidic water. Hole or basin in the ground surface formed when rock dissolves

climate that encourages karst topography

humid

stage of karst evolution; limestone is almost gone

late

introduction of this into a cave encourages plants

light

Bedrock of the karst environment

most likely limestone, but may be any soft rock that easily dissolves in carbonic acid

last stage of karst evolution

much of the original limestone has been completely dissolved away. All that remains are a few scattered hills and little chunks of limestone left poking through the surface. From the surface, the landscape may not bear any noticeable signs of what is going on beneath the surface, except for a few sinkholes here and there.

Natural ___ on our skin can damage speleothems.

oil

stalagmite

on the floor

Limestone ___: karst feature of old glacial areas

pavement

Intermediate stage

sinkholes grow to form solution valleys, some of which can become quite large with time.

solution valley

solution valleys form when sinkholes grow and merge

scientist who studies caves

speleologist

speleothem that hangs from the ceiling

stalactite

speleothem that rises from the floor

stalagmite

cave

underground opening that forms when soft rock dissolves away. The water is acidic groundwater, and it moves underground after infiltrating the surface. Caves may have hidden features and spectacular formations. An opening underground formed by dissolution of limestone

What environmental conditions do you think are necessary for the development of karst topography? How would temperature affect the development of karst landscapes?

Karst topography is limited to areas that have limestone rock close to the surface, and adequate precipitation to dissolve the limestone. Humid and warm climates encourage the development of karst topography because they have adequate water and warmth. Thus, karst topography is most common in humid tropical areas. Cold environments, on the other hand, discourage the development of karst features because the cooler temperatures slow the eating away of the limestone.

Karst environments rarely have large bodies of surface water over them. Why do you think this is? What happens to precipitation and runoff water in karst environments?

Much of the water moves underground, easily soaking into cracks and worn-down areas of the underlying limestone

Karst topography is only found over about 8% of Earth's land. What conditions must be met for karst topography to develop? Why doesn't it occur more often?

The development of karst topography requires water and soft rocks, which are most often limestone, but can also be dolomite, chalk, marble, or gypsum. The environment must be one in which there is enough precipitation and runoff to dissolve the rocks. It must also be an environment that is underlain by rocks that easily dissolve. If it is underlain by granite or sandstone, which are much harder to dissolve, you will not get the same karst development.

calcium carbonate

The mineralogical composition of cave formations, such as columns

spring

Water springs upward from an underground crack. It will flow onto the surface of the ground. A place where water runs on to the surface from below the ground