Frostwork

Last updated
Frostwork in Jewel Cave, South Dakota. Jewel Cave 3.jpg
Frostwork in Jewel Cave, South Dakota.
Architectural "frost-work" in carved stone, on the Diana Fountain, London, c. 1690 Diana Fountain in Bushy Park 3 (cropped).jpg
Architectural "frost-work" in carved stone, on the Diana Fountain, London, c. 1690

In geology, frostwork is a type of speleothem (cave formation) with acicular ("needle-like") growths almost always composed of aragonite (a polymorph of calcite) or calcite replaced aragonite. [1] It is a variety of anthodite. Frostwork can also be made of opal or gypsum. [2] In some caves frostwork may grow on top of cave popcorn or boxwork.

Contents

In architecture frost-work or frostwork refers to a style of rustication carved with a vertically-oriented pattern evoking hanging pond-weed or algae, or icicles. It is mainly found in garden architecture, where water is to flow over or near the surface. [3] Other decorative arts may use the term for other decorative patterns imitating frost or ice.

Formation

The origin of frostwork is somewhat controversial. Formation of cave frostwork has been attributed to moist, circulating air which, containing dissolved calcium carbonate, drifted against rock surfaces and coated them with the delicate crystals. Frostwork has also been attributed to water seepage from cave passageways in which there are relatively high evaporation rates.

Occurrence

Notable frostwork deposits are found in a number of caves in the Black Hills region of South Dakota, US, most notable in Wind Cave National Park and Jewel Cave National Monument and Timpanogos Cave in Utah. Perhaps the most extensive displays known are found in Lechuguilla Cave, New Mexico, US.

Related Research Articles

Limestone Sedimentary rocks made of calcium carbonate

Limestone is a type of carbonate sedimentary rock. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO3). A closely related rock is dolomite, which contains a high percentage of the mineral dolomite, CaMg(CO3)2. In old USGS publications, dolomite was referred to as magnesian limestone, a term now reserved for magnesium-deficient dolomites or magnesium-rich limestones.

Stalactite

A stalactite is a type of formation that hangs from the ceiling of caves, hot springs, or manmade structures such as bridges and mines. Any material that is soluble, can be deposited as a colloid, or is in suspension, or is capable of being melted, may form a stalactite. Stalactites may be composed of lava, minerals, mud, peat, pitch, sand, sinter, and amberat. A stalactite is not necessarily a speleothem, though speleothems are the most common form of stalactite because of the abundance of limestone caves.

Aragonite Calcium carbonate polymorph

Aragonite is a carbonate mineral, one of the three most common naturally occurring crystal forms of calcium carbonate, CaCO3 (the other forms being the minerals calcite and vaterite). It is formed by biological and physical processes, including precipitation from marine and freshwater environments.

Travertine A form of limestone deposited by mineral springs

Travertine is a form of limestone deposited by mineral springs, especially hot springs. Travertine often has a fibrous or concentric appearance and exists in white, tan, cream-colored, and even rusty varieties. It is formed by a process of rapid precipitation of calcium carbonate, often at the mouth of a hot spring or in a limestone cave. In the latter, it can form stalactites, stalagmites, and other speleothems. It is frequently used in Italy and elsewhere as a building material.

Speleothem A structure formed in a cave by the deposition of minerals from water

Speleothems, commonly known as cave formations, are secondary mineral deposits formed in a cave. Speleothems typically form in limestone or dolomite solutional caves. The term "speleothem," as first introduced by Moore (1952), is derived from the Greek words spēlaion "cave" + théma "deposit". The definition of "speleothem," in most publications, specifically excludes secondary mineral deposits in mines, tunnels, and other man-made structures. Hill and Forti more concisely defined "secondary minerals" which create speleothems in caves:

A "secondary" mineral is one which is derived by a physicochemical reaction from a primary mineral in bedrock or detritus, and/or deposited because of a unique set of conditions in a cave; i.e., the cave environment has influenced the mineral's deposition.

Wind Cave National Park

Wind Cave National Park is an American national park located 10 miles (16 km) north of the town of Hot Springs in western South Dakota. Established in 1903 by President Theodore Roosevelt, it was the seventh national park and the first cave to be designated a national park anywhere in the world. The cave is notable for its calcite formations known as boxwork, as well as its frostwork. Approximately 95 percent of the world's discovered boxwork formations are found in Wind Cave. The cave is recognized as the densest cave system in the world, with the greatest passage volume per cubic mile. Wind Cave is one of the longest caves in the world with 149.01 miles (239.81 km) of explored cave passageways, as of 2018. Above ground, the park includes the largest remaining natural mixed-grass prairie in the United States.

Helictite Seemingly space-set speleothems

A helictite is a speleothem found in a limestone cave that changes its axis from the vertical at one or more stages during its growth. Helictites have a curving or angular form that looks as if they were grown in zero gravity. They are most likely the result of capillary forces acting on tiny water droplets, a force often strong enough at this scale to defy gravity.

Jewel Cave National Monument

Jewel Cave National Monument contains Jewel Cave, currently the third longest cave in the world, with 200.3 miles of mapped passageways. It is located approximately 13 miles (21 km) west of the town of Custer in Black Hills of South Dakota. It became a national monument in 1908.

Dolomite (rock) Sedimentary carbonate rock that contains a high percentage of the mineral dolomite

Dolomite (also known as dolomite rock, dolostone or dolomitic rock) is a sedimentary carbonate rock that contains a high percentage of the mineral dolomite, CaMg(CO3)2. In old USGS publications, it was referred to as magnesian limestone, a term now reserved for magnesium-deficient dolomites or magnesium-rich limestones. Dolomite has a stoichiometric ratio of nearly equal amounts of magnesium and calcium. Most dolomite rock formed as a magnesium replacement of limestone or lime mud before lithification. Dolomite rock is resistant to erosion and can either contain bedded layers or be unbedded. It is less soluble than limestone in weakly acidic groundwater, but it can still develop solution features (karst) over time. Dolomite rock can act as an oil and natural gas reservoir.

Timpanogos Cave National Monument

Timpanogos Cave National Monument is a United States National Monument protecting the Timpanogos Cave Historic District and a cave system on Mount Timpanogos in American Fork Canyon in the Wasatch Range, near Highland, Utah, in the United States. The site is managed by the National Park Service. The 1.5-mile (2.4 km) trail to the cave is steep, gaining close to 1,000 feet (300 m), but paved and fairly wide, making the caves accessible to most. The three caves of the system, one of which is specifically called Timpanogos Cave, are only viewable on guided tours when the monument is open, usually from May through September depending on snow conditions and funding. There is the standard tour going through the cave system, and an Introduction to Caving tour which teaches Leave No Trace caving and goes further into Hansen Cave.

Flowstone

Flowstones are composed of sheetlike deposits of calcite or other carbonate minerals, formed where water flows down the walls or along the floors of a cave. They are typically found in "solution caves", in limestone, where they are the most common speleothem. However, they may form in any type of cave where water enters that has picked up dissolved minerals. Flowstones are formed via the degassing of vadose percolation waters.

Cave popcorn

Cave popcorn, or coralloids, are small nodes of calcite, aragonite or gypsum that form on surfaces in caves, especially limestone caves. They are a common type of speleothem.

Delaware Basin Geologic depositional and structural basin in West Texas and southern New Mexico, famous for holding large oil fields

The Delaware Basin is a geologic depositional and structural basin in West Texas and southern New Mexico, famous for holding large oil fields and for a fossilized reef exposed at the surface. Guadalupe Mountains National Park and Carlsbad Caverns National Park protect part of the basin. It is part of the larger Permian Basin, itself contained within the Mid-Continent oil province.

Cave of the Mounds

Cave of the Mounds, a natural limestone cave located near Blue Mounds, Wisconsin, United States, is named for two nearby hills called the Blue Mounds. It is located in the southern slope of the east hill. The cave's beauty comes from its many varieties of mineral formations called speleothems. The Chicago Academy of Sciences considers the Cave of the Mounds to be "the significant cave of the upper Midwest" because of its beauty, and it is promoted as the "jewel box" of major American caves. In 1987, the United States Department of the Interior and the National Park Service designated the cave as a National Natural Landmark.

Anthodite

Anthodites (Greek ἄνθος ánthos, "flower", -ode, adjectival combining form, -ite adjectival suffix) are speleothems (cave formations) composed of long needle-like crystals situated in clusters which radiate outward from a common base. The "needles" may be quill-like or feathery. Most anthodites are made of the mineral aragonite (a variety of calcium carbonate, CaCO3), although some are composed of gypsum (CaSO4·2H2O).

Boxwork Cave crystals constituting box-like blades between bygone bedrocks

In geology, boxwork can have two possible meanings. In cave geology, boxwork is an uncommon type of mineral structure, or speleogen, occasionally found in caves and erosive environments. In mining geology, boxwork refers to quartz-lined cavities retaining the shape of the dissolved ore minerals in gossans.

Mercer Caverns

Mercer Caverns is a show cave located one mile north of Murphys in Calaveras County California. It is named after the gold prospector Walter J. Mercer who discovered the caves around 1885 and filed a claim. The caverns have a large number of speleothems, stalactites, and stalagmites. It is formed in a marble unit known as the Calaveras Formation. It also contains a large display of aragonite frostwork. The standard tour of the cave descends 160 feet, 208 steps down and 232 up in a traverse between the natural and an artificial entrance. The cave was mapped in 1986 to a length of 3389 feet and a total depth of 192 feet. The map can be viewed on the cave's web site.

Solutional cave

A solutional cave or karst cave is a cave usually formed in the soluble rock limestone. It is the most frequently occurring type of cave. It can also form in other rocks, including chalk, dolomite, marble, salt beds, and gypsum.

Calcite rafts Cave-crystallized calcite crusts

Calcite crystals form on the surface of quiescent bodies of water, even when the bulk water is not supersaturated with respect to calcium carbonate. The crystals grow, attach to one other and appear to be floating rafts of a white, opaque material. The floating materials have been referred to as calcite rafts or "leopard spots".

Calthemite Secondary calcium carbonate deposit growing under man-made structures

Calthemite is a secondary deposit, derived from concrete, lime, mortar or other calcareous material outside the cave environment. Calthemites grow on or under, man-made structures and mimic the shapes and forms of cave speleothems, such as stalactites, stalagmites, flowstone etc. Calthemite is derived from the Latin calx "lime" + Latin < Greek théma, "deposit" meaning ‘something laid down’, and the Latin –ita < Greek -itēs – used as a suffix indicating a mineral or rock. The term "speleothem", due to its definition can only be used to describe secondary deposits in caves and does not include secondary deposits outside the cave environment.

References

  1. Hill, C. and Forti, P. (1997), Cave Minerals of the World, National Speleological Society, 2nd Edition.
  2. KellerLynn, K. (2009). Wind Cave National Park Geologic Resources Inventory Report (PDF). Denver: National Park Service.
  3. Looking at buildings, "Rustication"