Featured Article Summary #238

Laguna Miscanti is a brackish lake on the Altiplano of northern Chile’s Antofagasta Region, covering about 13 km² and shaped like an arrowhead. It is mainly supplied and drained by groundwater, with no permanent streams flowing in or out, and it sits among volcanoes in the Central Andes. Nearby to the south is the smaller Laguna Miñiques, separated from Miscanti by a lava flow. The lake was formed by tectonic activity about 22,000 years ago, grew during wetter conditions in the late Pleistocene, and later shrank in a drier Holocene climate, possibly drying out; it then reformed about 3,400 years ago and has remained since. Today it is a key bird breeding site and an important tourist spot in the Los Flamencos National Reserve, and prehistoric people also hunted there, with archaeological sites found nearby. The name “Miscanti” comes from the Kunza language, which was once spoken around the Salar de Atacama and the Loa River valley. It likely means something specific in Kunza, and it has alternate spellings such as Miskanti or Miscanter—possibly with “Miscanter” being the original Kunza name, while “Miscanti” may be the Quechua version. Laguna Miscanti is a lake in Chile’s Central Andes, southeast of the Salar de Atacama, near Socaire and San Pedro de Atacama. It covers about 12–13 km² and has a shallow maximum depth of around 10 m, with no streams feeding it directly. The lake’s clear, brackish water is mainly supplied by groundwater from nearby mountains, and it is a closed basin where water mostly leaves by evaporation, with some underground drainage that helps stop it from turning into a salt flat. In the past, Laguna Miscanti was over twice as large as it is today, with water levels about 29 m higher, reaching 4179 m altitude. During peak high-water periods, it likely connected with nearby lakes or overflowed into the Pampa Varela basin, covering alluvial fans and leaving behind terraces, lake sediments, and wave-shaped rock surfaces; these deposits include stromatoliths, sands, volcanic material, gravel, diatomites, and calcarenites. Sediments accumulated at roughly 1 mm per year, eventually forming 6–10 m thick layers, and the high water levels supported more life, including algae and plant fossils. The Laguna Miscanti catchment covers 320 km² and is made mainly of volcanic and sedimentary rocks from the Miocene to the Holocene. Several high Quaternary volcanoes, including Cerro Miscanti and Cerro Miñiques, belong to the Andean Volcanic Belt formed by the Nazca Plate subducting beneath the South American Plate. The area is shaped by north–south mountain ranges that divide basins with salt flats and lakes; Laguna Miscanti sits in basins linked to activity on the Quebrada Nacimiento fault, which also controls groundwater flow. This fault is part of a larger fault system between the Western Cordillera and the Cordillera Domeyko, and it may have influenced nearby volcano formation and the development of the Miscanti Ridge.