Lake Palomas
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| Lake Palomas | |
|---|---|
  Lake Palomas | |
| Coordinates | 31°13′N 106°59′W / 31.22°N 106.99°W |
| Type | Former lake |
| Primary inflows | Río Casas Grandes, Río del Carmen, Mimbres River or Río Santa María |
| Catchment area | 60,000 square kilometres (23,000 sq mi) |
| Max. length | 130 miles (210 km) |
| Max. width | 40 miles (64 km) |
| Surface area | 3,500 square miles (9,100 km2) |
Lake Palomas is a former lake in New Mexico, United States, and Chihuahua, Mexico. This lake was relatively large and reached a size of about 9,100 square kilometres (3,500 mi2) during its highstands. Preceded by Lake Cabeza de Vaca, it formed during the Pleistocene and continued into the Holocene, when several different lake phases occurred. Presently its basin is a major source of airborne dust in the region.
Lake Palomas is named after Puerto Palomas, Chihuahua. The northwestern part of the Lake Palomas basin is also known as "Guzmán Sink".[1]
Hydrogeography
During highstands the lake was about 210 kilometres (130 mi) long and in some places 64 kilometres (40 mi) wide. It covered a surface area possibly over 9,100 square kilometres (3,500 mi2) during these highstands and 5,200 square kilometres (2,000 mi2) at lowstands.[1] At these sizes it was one of the largest pluvial lakes in the southwestern United States during the late Pleistocene.[2] Most of the lake was located in Mexico, with only a bay between the West Potrillo Mountains and the Tres Hermanas Mountains extending into New Mexico.[3]
At highstand, Lake Palomas contained the islands Unión and Santa María. The islands were 26 square kilometres (10 mi2) and 650 square kilometres (250 mi2), respectively.[1] Islands were formed by the Carrizal Mountains, the Guzmán Mountains and the Las Muertos Mountains.[3]
The lake was subdivided into three basins (east, central and west) by upthrust Cretaceous mountains and Tertiary intrusives.[1] None of these basins were very deep during the history of Lake Palomas; the deepest point during La Mota time was in Salinas de Unión where the current basin floor is 120 metres (410 ft) beneath the La Mota shoreline.[4]
Lake Palomas has left over sediments ranging from gravel and sand at its shores and clay and silt in the centres of the basins that formed the lake.[5]
Hydrology
Inflow
The Río Casas Grandes, Río del Carmen, Mimbres River or Río Santa María either drained into Lake Palomas or had part of their course submerged by it.[6]
The catchment of Lake Palomas covered about 60,000 square kilometres (23,000 sq mi),[2] and was fully developed by about 200,000 years ago.[6]
Shorelines
Three different shorelines of Lake Palomas are known. These are the 1,200 metres (4,100 ft) La Mota, the 1,240 metres (4,070 ft) Guzmán and the Las Muertos at 1,230 metres (4,030 ft). The La Mota shorelines are noticeable on the northeastern side of the lake between Columbus, New Mexico, and Villa Ahumada, Chihuahua, where they are over 180 kilometres (110 mi). On the western side conversely, they are buried beneath alluvial deposits and thus difficult to recognize.[1]
Lower shorelines are also found, though they are less well developed. These include the 1,220 metres (4,010 ft) El Sancho, the 1,236 metres (4,056 ft) Santa Maria shoreline[1] and a mid-Holocene 1,190 metres (3,900 ft) shoreline.[7] Three shorelines of Holocene age are found at 1,225 metres (4,019 ft), 1,200 metres (3,900 ft) and 1,175 metres (3,855 ft) elevation, they correspond to the early Holocene, middle Holocene and the Little Ice Age, respectively.[8]
Shoreline features include beach ridges, river deltas, spits and wavecut platforms.[9][2] After the shrinkage of Lake Palomas and its successor lakes, wind erosion has occurred on the shoreline deposits. The eroded particles formed the Samalayuca Dune Fields upon deposition.[10]
Climate
The present-day climate of the Lake Palomas area is cold in winter and hot in summer. Precipitation totals about 300 millimetres (12 in), with high elevation areas reaching twice to thrice as much as lowland. Precipitation falls mostly in summer; the winter precipitation is controlled by the El Nino-Southern Oscillation.[2]
Lake levels at Lake Palomas were controlled by the position of the polar jet stream, which could drive storm systems into the region when it was positioned farther south.[7] The increased cloud cover and lower temperatures reduced evaporation and the storms added precipitation to the basin, causing lake levels to increase.[11] The North American Monsoon on the other hand does not appear to have played a major role in the lake history,[7] seeing as lake levels of Lake Palomas are correlated to lake levels in basins such as Silver Lake that are not monsoonally influenced.[11]
