Karst topography

1. Guided by,
associate Prof. ASHA MANJERY
Dept. of earth science 108/04/19

2. CONTENT
Introduction
Chemistry
Condition for karst formation
Morphological features
 conclusion
reference
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3. •.
INTRODUCTION
caves, sinkholes,stalagmites,stalactites,
speleogens, natural springs, losing streams,
natural bridges are main features
Karst topography is a geologic formation
shaped by the dissolution of a layer or layers of
soluble bedrock, usually carbonate rock such as
limestone or dolomite
The geological process of erosion can take
thousands of years to form Karst topography
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4. CHEMISTRY
Karst landforms are generally the result of
mildly acidic water acting on weakly soluble
bedrock
 The mildly acidic water begins to dissolve the
surface along bedding planes in the bedrock.
These fractures enlarge as the bedrock continues
to dissolve.
 Openings in the rock increase in size, and an
underground drainage system begins to develop,
allowing more water to pass through the area,
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5. The Limestone formation contains > 80%
calcium
Carbonates
Complex patterns of joints for conducting water
through subsurface drainage channels
An air-containing zone between ground surface
and water Table
Vegetation cover to supply organic acids
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6. •Caverns
•Sinkholes
•Disappearing streams
•cave deposits :
Speleogens
stalactites
stalagmites
columns
•Spring deposits:
geodes
kankars
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7. The formation and development of caves is
known as speleogenesis
Caverns are commonly interlinked with one
another. The linking passages are known as
galleries
Caves are resulted from the dissolution of
carbonate rock by circulating groundwater.
Limestone caves are generally believed to
result from dissolution by carbonic acid.
The rate of cave formation is related to the rate
of dissolution
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9. SINKHOLES
An opening which connects the cave with the surface is
called sinkhole
Some sinkholes are formed when caves have
collapsed-collapse sink hole, others are formed from
dissolution-solution sinkhole
Many sinkholes are located at the
intersection of joints.
New sinkholes are forming because of the
lowering of the water table due to
excessive pumping.08/04/19 9

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12. In karst areas, streams often disappear into
the ground usually at a sinkhole. some
disappearing streams eventually return to the
surface as natural spring.
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13. Speleogens are irregular or distinctive shapes
of carbonate rock etched from bedrock by
dripping or running water.
• Speleogens can form where bedrock is not
uniform in chemical composition.
speleothems including cone-shaped stalactites ,
stalagmites , columns
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14. Stalactites are formed by the deposition of calcium
carbonate and other minerals, which is precipitate
from mineralized water solutions &hanging from the
roof of a cave
 The same water drops that fall from the tip of a
stalactite deposit more calcite on the floor below,
eventually resulting in a rounded or cone-shaped
stalagmite
If these formations grow together, the result is
known as a columns
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16. Spring deposits
Under ground water highly charged with mineral matter
emerging on the surface in the form of spring is often
found to form loose , superficial deposits of Si or CaCO3.
GEODES: A rock mass with a spherical cavity filled with
mineral crystals. Commonly occur in Limestone & shale
KANKARS: In unconsolidated sediments, such
deposition in the interspaces causes cementation of loose
material and their consequent conversion into compact
rocks. The compact masses so produced are called
Kankars.
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17. CONCLUSION
• Karst topography is a geologic formation shaped by
the dissolution of a layer or layers of soluble bedrock.
• Mildly acidic water begins to dissolve the surface along
bedding planes in the bedrock.
• Mainly it seen in limestone terrance's .
• caves, sinkholes,stalagmites,stalactites, speleogens,
natural springs, losing streams, natural bridges are the
main features produced by karst topography.
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18. REFERENCE
William D . Thornbary (1954), principles of geomorphology ,
Wiley eastern limited, p.p- 303 to 335.
O.D Von engeln (1942), geomorphology, the MacMillan
company, p.p- 563 to 588
Edward Derbyshire (1976), geomorphology & climate , John
Wiley and sons ,p.p - 345 ,391 to 399.
Websites
www.goole.com
www. Wikepedia.com
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