Carachipampa

Carachipampa lies in the Catamarca Province^[1] of northwestern Argentina.^[2] It is a black volcanic cone with its summit on the southeastern crater rim, surrounded by a field of lava flows that were fed from the northwestern side of the cone.^[3] Part of the southeastern flank of the cone is collapsed.^[4] The occurrence of eroded scoria cones and lava domes has been reported.^[5] The lava flows reach thicknesses of 2–6 metres (6 ft 7 in – 19 ft 8 in) and lengths of 8 kilometres (5.0 mi),^[6] and consist of mafic andesite^[7] that defines a calc-alkaline suite. Phenocrysts are mostly amphibole, clinopyroxene and olivine.^[8] Rock samples from the volcano have been analyzed.^[9]

The volcano erupted 750,000 years ago^[10] and is part of the fourth volcanic stage in the region.^[7] There are a number of mafic volcanic centres in the southern Puna, including Antofagasta de la Sierra north of Carachipampa.^[11] Cerro Blanco farther southwest produced ignimbrites, which cover the terrain southwest of Carachipampa,^[12] and is still active.^[2] Seismic tomography has identified a low-speed anomaly underneath Carachipampa, which connects to it and to several neighbouring volcanoes like Galán and Ojos del Salado.^[13] The so-called "Cerro Galán Magmatic Body" lies north of Carachipampa; the volcano lies above its margin.^[14] A major crustal lineament bears the name "Carachipampa-Farallon Negro".^[15] There is evidence of neotectonic activity at Carachipampa.^[16]

The cone lies at the centre, and the lowest point, of a^[17] 149 by 64 kilometres (93 mi × 40 mi) wide^[18] deserted, vegetation-free^[a] plain^[20] that is one of the lowest-elevation areas in the Puna.^[21] To the west, across a ridge, lies the Incahuasi basin,^[22] to the east there is a sharp demarcation with^[23] the Campo de Piedra Pomez^[2] with numerous yardangs carved into ignimbrites. Permian red beds and Paleogene sediments crop out close to Carachipampa.^[2] Other rock formations around the Carachipampa plain range in age from Neoproterozoic over Devonian. The basin is filled with sediments, reaching thicknesses of 700 metres (2,300 ft).^[18] The basin is notable for the giant (up to 1.5 metres (4 ft 11 in) high), wind-formed megaripples;^[24] they are found southwest of Carachipampa in the valley that runs to Cerro Blanco.^[25] Winds have removed fine materials, leaving only granular material on the plain,^[20] and eroded sediments from wetlands.^[26]

The region has a cold and arid climate,^[23] as the Andes prevent moisture from the Atlantic. Winds blow mostly from the northwest and can be intense, explaining the widespread aeolian landforms at Carachipampa.^[27] Other traits of the climate are high UV radiation, large daily temperature fluctuations and frequent drying, which make the environment similar to that experienced on Mars.^[1]

There are two major waterbodies at Carachipampa,^[28] which surround the volcano:^[29]

• Laguna Carachipampa covers a surface of 0.079 square kilometres (0.031 sq mi). Located at 2,915 metres (9,564 ft)^[30] or 3,018 metres (9,902 ft) elevation,^[31] it is hypersaline^[32] and contains salty chloride- and sulfate-rich waters^[33] which precipitate aragonite.^[34] Its waters are mostly more than 60 years old.^[35] The lake is flanked by pools of hydrothermal water,^[36] and both them and (in lesser measure) the lake^[36] feature a microbial ecosystem, similar to a number of other Puna lakes,^[37] which has been compared to ancient environments in Mars's Jezero crater.^[38] The microbes produce microbial mats, oncoids^[b] and stromatolites;^[40] they consist mainly of the carbonates^[31] aragonite and dolomite.^[38] They extend along 2 kilometres (1.2 mi) of the lake, occasionally forming flat pavements.^[36] Some microbialites are of Holocene age.^[41] Flamingos breed at Laguna Carachipampa;^[42] other birds encountered at Carachipampa include the Andean goose^[43] and the Puna plover.^[44]
• Salar Carachipampa is a salt pan south-southeast from the volcano.^[45] It has an area of 50 square kilometres (19 sq mi)^[46] and sometimes fills with water, forming an ephemeral lake.^[2] It is partially covered by wind-transported sediments^[47] and surrounded by alluvial fans.^[38] A smaller volcano lies south of the salt pan.^[48]

Several watercourses, many of which are ephemeral, flow into the Carachipampa waterbodies. These include the Pirica and Colorado rivers and the creek at El Peñón.^[28] At least one creek feeds the waterbodies.^[49] The Pirica and Colorado rivers may still flow to Carachipampa.^[50] Wetlands are found mainly north of Carachipampa^[51] and cover an area of about 0.361 square kilometres (0.139 sq mi).^[52]

It is probable that in the past, the basin extended to Fiambalá, before it was separated by volcanic activity.^[53] Later, activity of the Antofagasta de la Sierra volcanoes farther north removed inflow from the north^[54] although it is possible that water still flows underground from Antofagasta to Carachipampa.^[55] Until 1905 years ago, the climate was wetter and a terrace formed at Laguna Carachipampa.^[56] Active wetlands^[57] and beach environments developed around 644 years ago.^[56]

The town of El Peñón is east of Carachipampa,^[2] and the volcano/lake is a tourism destination.^[52] National Route 53 [es]^[58][c] from Belen to Antofagasta de la Sierra, Catamarca passes by Carachipampa.^[45] There is no evidence of agriculture or archeological sites around Carachipampa,^[61] but the inhabitants of Peñón used the wetlands as pastures.^[51] In 1978, there was a habitation named Carachi Pampa.^[62] Bolivia briefly claimed the southern Puna including Carachipampa during the Puna de Atacama dispute in the early 20th century.^[63]

Owing to its extreme environmental conditions, Carachipampa has been used as an Earth-based analogue to Mars.^[1] Alum and salt were extracted from Carachipampa,^[64] and presently the company Lake Resources owns rights about a lithium extraction project at Carachipampa.^[65] The name may refer to Quechua pampa, "plain"; the first component may be a reference to either kachi, "salt", or kachina, a type of white ground, or Qáranpampa, "Erial sterile field",^[66] or a word in the Cacán language that means "scab" and may be a reference to skin burns.^[67]