What is an example of a speleothem?
What is an example of a speleothem?
Examples of speleothems are stalactites, stalagmites, flowstones, cave coral, cave drapery, cave curtains, and cave crystals.
What does speleothem mean?
Speleothems are secondary mineral deposits formed in caves by flowing, dripping, ponded, or seeping water. The most commonly occurring minerals are calcite, aragonite, and gypsum although many other minerals have been found in speleothems in minor amounts.
What is a speleothem record?
Speleothems are mineral deposits formed from groundwater within underground caverns. Stalagmites, stalactites, and other forms may be annually banded or contain compounds that can be radiometrically dated. The thickness of these depositional layers or isotopic records can be used to determine past climate conditions.
What can speleothems tell us?
Geologists refer to the mineral formations in caves as “speleothems.” While the water flows, the speleothems grow in thin, shiny layers. The amount of growth is an indicator of how much ground water dripped into the cave. Little growth might indicate a drought, just as rapid growth could point to heavy precipitation.
What are some common speleothem types?
Common speleothems include dripstones (such as stalactites, stalagmites, straws, columns, or pillars), flowstones (such as shawls, curtains, draperies, or “cave bacon”), pore deposits (such as helictites and cave corals), and pool deposits (such as rimstone, dogtooth spar, cave pearls, shelftstone, or lily pads).
How speleothems are formed?
Speleothems, often called cave formations, are formed as rainwater passes through the soil and absorbs carbon dioxide. As water and carbon dioxide mix it forms a weak acid called carbonic acid, which helps to dissolve underlying rock.
How does speleothem analysis help us to understand past climate conditions?
Once they stop growing, their smooth, wet-looking surface turns dull as the speleothems become dirty and eroded. Because the amount of water making its way into caves determines the amount speleothems grow, their layers can indicate times of both heavy precipitation and drought in the area.
What structure forms when a speleothem is on the ceiling?
The speleothems with which most people are familiar are stalactites and stalagmites. Stalactites grow down from the cave ceiling, while stalagmites grow up from the cave floor.