The 7th in our new challenge layout catering for all aspects of nature for us nature lovers.
As you can see the title will start with the category which will make it easier for me when choosing what challenge to do next, I can see the challenges I have already run in this category.
For this challenge please add your images of CAVES.
> A cave or cavern is a natural underground space.
> The word cave also includes smaller spaces like rock shelters, sea caves, and grottos.
> The formation and development of caves is known as speleogenesis. Caves are formed by various geologic processes. These may involve a combination of chemical processes, erosion from water, tectonic forces, microorganisms, pressure, atmospheric influences, and even digging.
Most caves are formed in limestone by dissolution.
> Solutional cave
Solutional caves are the most frequently occurring caves and such caves form in rock that is soluble, such as limestone, but can also form in other rocks, including chalk, dolomite, marble, salt, and gypsum. Rock is dissolved by natural acid in groundwater that seeps through bedding-planes, faults, joints and so on. Over geological epochs cracks expand to become caves or cave systems.
> Primary cave
Some caves are formed at the same time as the surrounding rock. These are sometimes called primary caves. Lava tubes are formed through volcanic activity and are the most common ‘primary’ caves.
> Sea cave or littoral cave
Sea caves are found along coasts around the world. A special case is littoral caves, which are formed by wave action in zones of weakness in sea cliffs. Often these weaknesses are faults, but they may also be dykes or bedding-plane contacts.
> Corrasional cave or erosional cave
Corrasional or erosional caves are those that form entirely by erosion by flowing streams carrying rocks and other sediments. These can form in any type of rock, including hard rocks such as granite.
> Glacier cave
Glacier caves occur in ice and under glaciers and are formed by melting. They are also influenced by the very slow flow of the ice, which tends to close the caves again.
> Fracture cave
Fracture caves are formed when layers of more soluble minerals, such as gypsum, dissolve out from between layers of less soluble rock. These rocks fracture and collapse in blocks of stone.
> Talus cave
Talus caves are the openings between rocks that have fallen down into a pile, often at the bases of cliffs (called “talus”).
> Anchihaline cave
Anchihaline caves are caves, usually coastal, containing a mixture of freshwater and saline water (usually sea water). They occur in many parts of the world, and often contain highly specialized and endemic faunas.
> Worlds Five Largest Caves (Known to Man)
Mammoth Cave, Kentucky, USA
Jewel Cave, South Dakota, USA
Optymistychna Cave, Ukraine
Wind Cave, South Dakota, USA
Sistema Sac Actun, Mexico
Information courtesy of Wikipedia
Vote for your favourite!
1st place winners will have their photo used as the group Avatar for a period of time.
Then 1st, 2nd and 3rd will have their photo’s posted on the groups Feature Board.
1st place member will be become a featured member.
ENTRIES MUST BE ADDED TO THE GROUP FIRST OR BE DELETED FROM THE CHALLENGE.