Tafoni are small cave

Cave

A cave or cavern is a natural underground space large enough for a human to enter. The term applies to natural cavities some part of which is in total darkness. The word cave also includes smaller spaces like rock shelters, sea caves, and grottos.Speleology is the science of exploration and study...

-like features found in granular rock such as sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

, with rounded entrances and smooth concave walls. They often occur in groups that can riddle a hillside, cliff, or other rock formation. They can be found in all climate types, but are most abundant in intertidal areas and semi-arid and arid desert

Desert

A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...

s. Currently favored explanations controlling their formation include salt

Salt

In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...

 weathering, differential cementation

Cementation (geology)

Cementation involves ions carried in groundwater chemically precipitating to form new crystalline material within sediment pores; this is how "sediment" becomes "rock". The new pore-filling minerals form "bridges" between original sediment grains, thereby binding them together. So sand becomes...

, structural variation in permeability, and the length of the drying period between wettings. They also frequently occur in granitic rocks

Granite

Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...

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Small versions of tafoni are sometimes called alveoli; like the former, they are hypothesized to be results of salt weathering. Such tafoni are found in the Jodhpur

Jodhpur

Jodhpur , is the second largest city in the Indian state of Rajasthan. It is located west from the state capital, Jaipur and from the city of Ajmer. It was formerly the seat of a princely state of the same name, the capital of the kingdom known as Marwar...

-Ajmer

Ajmer

Ajmer , formerly written as Ajmere, is a city in Ajmer District in Rajasthan state in India. Ajmer has a population of around 800,000 , and is located west of the Rajasthan state capital Jaipur, 200 km from Jodhpur, 274 km from Udaipur, 439 km from Jaisalmer, and 391 km from...

 section of India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

's Thar Desert

Thar Desert

The Thar Desert |Punjab]] province. The Cholistan Desert adjoins the Thar desert spreading into Pakistani Punjab province.-Location and description:...

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This type of weathering is also referred to as honeycomb weathering

Honeycomb weathering

Honeycomb weathering, also known as fretting, cavernous weathering, alveoli/alveolar weathering, stone lattice, stone lace or miniature tafoni weathering is a type of salt weathering common on coastal and semi-arid granites, sandstones and limestones...

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The etymology

Etymology

Etymology is the study of the history of words, their origins, and how their form and meaning have changed over time.For languages with a long written history, etymologists make use of texts in these languages and texts about the languages to gather knowledge about how words were used during...

 of the word "tafoni" is unclear. Tafoni may come from the Greek

Greek language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 word taphos, "tomb". Tafoni may also stem from a Corsican

Corsican language

Corsican is a Italo-Dalmatian Romance language spoken and written on the islands of Corsica and northern Sardinia . Corsican is the traditional native language of the Corsican people, and was long the vernacular language alongside the Italian, official language in Corsica until 1859, which was...

 (French) word taffoni, meaning "windows", or from tafonare meaning "to perforate". In Sicilian

Sicilian language

Sicilian is a Romance language. Its dialects make up the Extreme-Southern Italian language group, which are spoken on the island of Sicily and its satellite islands; in southern and central Calabria ; in the southern parts of Apulia, the Salento ; and Campania, on the Italian mainland, where it is...

, tafoni means "windows". The earliest known publication of the term “tafoni” was in 1882.

External links

• www.tafoni.com Comprehensive explanation of tafoni, explanations of how they form, images, references