A557, Wind Cave National Park, South Dakota, USA, 2004

geology Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Ea ...

, boxwork is defined as a

honeycomb A honeycomb is a mass of hexagonal prismatic wax cells built by honey bees in their nests to contain their larvae and stores of honey and pollen. Beekeepers may remove the entire honeycomb to harvest honey. Honey bees consume about of honey t ...

-like structure that can form in some fractured or jointed

sedimentary Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

rocks. If the fractures in the host rock are mineralized, they can become more resistant to weathering than the surrounding rock, and subsequent erosion can produce boxwork structures. In mining geology, boxwork is a set of (typically)

quartz Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical ...

-lined cavities, retaining the shape of the dissolved ore

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ...

s, in

gossan Gossan (eiserner hut or eisenhut) is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein. In the ''classic'' gossan or iron cap all that remains is iron oxides and quartz, often ...

s. In classical geology or

mineralogy Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical) properties of minerals and mineralized artifacts. Specific studies within mineralogy include the proce ...

these mineral casts would not be called boxwork, but would instead be called

pseudomorph In mineralogy, a pseudomorph is a mineral or mineral compound that appears in an atypical form ( crystal system), resulting from a substitution process in which the appearance and dimensions remain constant, but the original mineral is replaced b ...

s, or epimorphs. In

cave A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...

geology, boxwork is an uncommon type of mineral structure, or speleogen (similar to a

speleothem A speleothem (; ) is a geological formation by mineral deposits that accumulate over time in natural caves. Speleothems most commonly form in calcareous caves due to carbonate dissolution reactions. They can take a variety of forms, depending o ...

, but formed by erosion rather than accretion), occasionally found in caves and

erosive Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is di ...

environments.

Caves

According to KellerLynn, "Boxwork is a speleogen, forming when bedrock between preexisting calcite veins were preferentially weathered away as the cave developed." Boxwork is commonly composed of thin blades of the mineral

calcite Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on scra ...

that project from cave walls or ceilings that intersect one another at various angles, forming a box-like or

pattern. The boxwork fins once filled cracks in the rock before the host cave formed. As the walls of the cave began to dissolve away, the more resistant vein and crack fillings did not, or at least dissolved at a slower rate than the surrounding rock, leaving the calcite fins projecting from the cave surfaces. Some of the most extensive boxwork deposits in the world are found in Wind Cave,

Wind Cave National Park Wind Cave National Park is an American national park located north of the town of Hot Springs in western South Dakota. Established on January 3, 1903 by President Theodore Roosevelt, it was the sixth national park in the U.S. and the first cave ...

South Dakota South Dakota (; Sioux language, Sioux: , ) is a U.S. state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Lakota people, Lakota and Dakota peo ...

, US. These boxwork deposits consist of calcite that precipitated in fractured host limestone. The limestone preferentially dissolved, leaving a crystalline calcite boxwork behind. Other outstanding examples occur in Cody Caves, Cody Caves Provincial Park in

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost Provinces and territories of Canada, province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include ...

, Canada. Boxwork can also be seen at Jewel Cave National Monument (near Wind Cave), and at Innerspace Caverns near Georgetown, Texas.

Gallery

File:Cave Boxwork often call cratework when this large. WInd Cave.JPG, Large boxwork ("cratework") in Wind Cave. File:Calcite boxwork, Wind Cave.jpg, Boxwork removed from Wind Cave. File:Tropfsteine.svg, Diagram of dripstone cave structures (boxworks labelled AE)

References

External links

Wind Cave National Park: Origin of Boxwork
{{Caves Speleothems Economic geology