Fluvial Landform ( 09.Cave )


                                                                                                                                                      Back to Fluvial Landform

Lava tube,Hawaii.
Lava tube,Hawaii.

  • cave/cavern is a natural underground space.
  • It is large enough for a human to enter.
  • Caves form naturally by the weathering of rock extend deep underground.
  • Cave refer to,such as;

                                       -sea caves
                                      -rock shelters
                                      -grottos.
  • Caves are formed by;

                                 -A combination of chemical processes
                                 -Erosion from water
                                 -Tectonic forces
                                - Microorganisms
                                 -Pressure
                                 -Atmospheric influences
                                - Digging
  • Most caves are formed in limestone by dissolution.
                 
Lechuguilla Cave, New Mexico
Lechuguilla Cave, New Mexico


solutional caves
  • Frequently occurring caves.
  • Formed in rock.
  • Soluble as;
                                              limestone                         chalk
                                             dolomite                            marble
                                              salt                                    gypsum
  • Rock is dissolved by natural acid in groundwater.
  • The largest & abundant solutional caves located in limestone.
  • Limestone dissolves under the action of;
                                  -rainwater
                                  -groundwater charged with H2CO3 (carbonic acid)
                                  -naturally occurring organic acids

  • The dissolution process  landform known as karst.
  • characterized by sinkholes.
  • Limestone caves are adorned with calcium carbonate.
  • Slow precipitation. 

e.g.
        Lechuguilla Cave,New Mexico
        Carlsbad Cavern
Large sea cave, Santa Cruz Island, California
Large sea cave, Santa Cruz Island, California

Primary caves
  • Lava tubes formed volcanic activity.
  • Lava flows downhill.
  • The surface cools and solidifies.
  • The hotter lava continues to flow under that crust.
  • The liquid lava beneath the crust flows out, a hollow tube remains, thus forming a cavity.
  •  Examples

                           Canary Islands, Hawaii
                           Kazumura Cave,Hilo
  • Other caves formed through volcanic activity include;

                               -rift caves
                              -lava mold caves
                             -open vertical volcanic conduits
                             -inflationary caves

Ogof Craig a Ffynnon, South Wales.
Ogof Craig a Ffynnon, South Wales.

Sea caves
  • Found along coasts.
  • Littoral caves formed by wave action.
  • Some wave-cut caves are above sea level .
  • In places such as;

                                   -Thailand's Phang Nga Bay


Erosional caves
  • Formed by erosion.
  • These can form in any type of rock.
  • There must be some zone of weakness to guide the water,as a fault,joint.
  • A sub type of the erosional cave is the wind/aeolian cave.




Fracture cave
  • Glacier caves occur in ice & under glaciers.
  • Formed by melting.
  • Influenced by very slow flow of the ice.
  • These are called ice caves.


Fracture caves
  • Formed by layers of more soluble minerals.
  • Dissolve out from between layers of less soluble rock.
  • These rocks fracture & collapse in blocks of stone.

Talus caves 

  • It called as talus.
  • Openings between rocks.
  • That fallen down into a pile at the bases of cliffs.

Anchialine caves 

  • Usually in coastal areas.
  • Containing a mixture of freshwater & saline water.
  • Contain highly specialized and endemic fauna.



Branchwork caves
  • They are made up of passages.
  • That join downstream as tributaries.
  • Formed near sinkholes 
  • Converges into other higher order branches downstream.

Angular Network caves

  • Formed by intersecting fissures of carbonate rock.
  • that have fractures widened by chemical erosion.
  • These fractures form high, narrow, straight passages.
  • That persist in widespread closed loops.


Anastomotic caves
  • Largely resemble surface braided streams.
  • Their passages separating.
  • They usually form one bed/ structure.
  • Only rarely cross into upper or lower beds.

Spongework caves
  • Formed by solution cavities are joined by mixing of chemically diverse water.
  • The cavities form a pattern.
  • That is three-dimensional & random, resembling a sponge.

Ramiform caves
  • Form as ;
                        irregular large rooms
                        galleries
                        passages
  • These randomized three-dimensional rooms
  • Form from a rising water table.
  • Erodes the carbonate rock with hydrogen-sulfide enriched water.

Pit caves 
  • Called as;
                       vertical caves
                       potholes cave
  • Consist of a vertical shaft
  • They may or may not be associated with one of the above structural patterns.

World's five longest surveyed caves

  1. Mammoth Cave, Kentucky, USA
  2. Sistema Sac Actun/Sistema Dos Ojos, Mexico
  3. Jewel Cave, South Dakota, USA
  4. Sistema Ox Bel Ha, Mexico
  5. Optymistychna Cave, Ukraine






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