Download Caverns and Mineral Deposits

Cavern and Mineral Deposits:
How Caverns Form






Limestone dissolves more easily
than other types of rock
Limestone is dissolved by
groundwater because it always
contains some carbonic acid.
Dissolving the calcite in limestone
creates/increases porosity
Limestone formations are also
split by fissures
After 1000's of years, cracks
become so large that they form
networks of underground tunnels
These tunnels are caverns, or
caves

Sinkholes form when parts of a cave roof collapses.

Ponds or lakes form when the sinkhole meets the water table
Karst Topography




In regions of caverns, most
rainwater enters the ground
through sinkholes and fissures,
and there are very few surface
rivers
Regions characterized by sinks,
sinkhole ponds, lost rivers, and
underground drainage are said to
have Karst Topography
The bedrock is calcite, dolomite,
or other minerals that dissolve
easily
Video link
Mineral Deposits by Groundwater





Minerals dissolved in groundwater are deposited in a variety of
ways
When water drips from the roof of a limestone cave is deposits
calcite as stalactites
On the floor beneath the stalactites, blunt, round masses called
stalagmites are formed.
Columns or pillars form when they meet
These are examples of dripstones, and only form when water can
evaporate above the water table.





Calcite deposits around mineral springs are called travertine
Hot water pours out of long hillside fissures, depositing some calcite
as it cools.
Geyserite forms around the opening of geysers, it is silica dissolved
from the hot igneous rock through which the geyser water pass.
Petrified wood is formed when minerals dissolved in groundwater
replace the decaying wood of buried trees
The most important groundwater deposit is the cement that binds
together sand grains and pebbles of sedimentary rocks.