Its waters are very rich in arsenic and otherwise salty and slightly alkaline; these properties and the regionally high UV radiation give Laguna Socompa extreme environmental conditions.

These stromatoliths are found on the southern shore of the lake and led to Laguna Socompa being declared a protected area.

Laguna Socompa is located at an elevation of 3,570 metres (11,710 ft)[1] in the Los Andes Department of the Salta Province in Argentina, close to the border with Chile.

[25] The lake is part of the windy,[23] cold, dry Puna where temperatures vary strongly between day and night, precipitation only occurs in summer.

[16] The small lakes in the Puna desert are influenced by extreme environmental conditions such as large amounts of toxic elements such as arsenic, high salinity and strong ultraviolet radiation[26] as the ozone column is less dense at high elevations;[1] these lakes in general receive more insolation than any other place on Earth.

[27] Because of the dry climate, most of the lakes lose water mainly through evaporation and thus tend to accumulate salt and arsenic.

About 27 bird species have been observed at Laguna Socompa, including both waterbirds and terrestrial birds; the most common are Anas flavirostris (yellow-billed teal), Hirundo rustica (barn swallow), Larus seranus, Lessonia rufa (austral negrito) and Lophonetta specularioides (crested duck).

[3] Microorganisms that live in the lakes and wetlands of the dry Andes have to resist harmful environmental traits[28] and thus become extremely hardy with e.g. high UV radiation tolerance.

They often also produce secondary metabolites that are of interest to the industry, such as medicine, UV blocking and bioremediation,[27] which has spurred research in these extreme environments.

strain 17 which was first isolated in Laguna Socompa; it possesses a number of genes involved in metabolizing arsenic and other toxic compounds and protecting and repairing the genome.

[38] Previously stromatoliths were known mainly from marine and carbonatic environments such as in the Bahamas, the Coorong Lagoon and Shark Bay in Australia, the Lagoa Salgada in Brazil and the Laguna Bacalar in Mexico.

The Laguna Socompa stromatoliths are the first to be discovered at elevations exceeding 3,500 metres (11,500 ft);[37] the presence of active hot springs may be responsible for their formation.

[14] The dominant bacteria in the stromatoliths are Microcoleus cyanobacteria and deinococci in the surface;[43] there are also eukaryotic algae, diatoms[44] of the genera Navicula and Nitzschia.