Lake Ballivián

Lake Ballivián is an ancient lake in the Altiplano of South America and is named after the Bolivian scholar Don Manuel Vicente Ballivian. It is part of a series of lakes which developed in the Titicaca basin along with Lake Mataro and Lake Cabana, reaching an altitude of 3,860 metres (12,660 ft). Lake Ballivián itself is of late Quaternary age and may have influenced the spread and development of animals in the Altiplano. In the southern Altiplano, Lake Escara may be coeval with Lake Ballivián.

The Altiplano in South America is a high plateau between the Eastern Cordillera and the Western Cordillera with an average altitude of 3,800 metres (12,500 ft) and a surface area of 200,000 square kilometres (77,000 sq mi). A number of evaporation landforms can be found in the Altiplano, including Salar de Uyuni and Salar de Coipasa. In the northern Altiplano lies Lake Titicaca.[1]

While the present-day Altiplano has an arid-semiarid climate,[1] it was formerly occupied by large lakes that grew and dried out in many phases. Of these lakes, Lake Ballivián and Lake Minchin were among the first to be described. Lake Mataro and Lake Cabana were later described in 1984 as previous ancient lakes in the Titicaca basin prior to Lake Ballivián.[2] The name Ballivián was coined in 1909,[3] it refers to the Bolivian scholar Don Manuel Vicente Ballivian.[4]

Lake Ballivián reached an altitude of 3,860 metres (12,660 ft). Another terrace at a height of 3,840 metres (12,600 ft) may correspond to a lake level drop of Ballivián.[5] The water surface would have covered 13,000–14,000 square kilometres (5,000–5,400 sq mi),[3] about one and a half as large as present day Lake Titicaca.[6] It is documented from the Lake Titicaca basin,[2] where it forms lacustrine abrasion surfaces and deposits of clay and sand at a height of 70 metres (230 ft) above the lake level.[7] The Azangaro formation in Peru and Ulloma formation in Bolivia are deposits of Lake Ballivián,[5] as are clays around Lake Titicaca.[8] Remains of the lake are found on the western and southern sides of the lake basin.[9]

Lake Ballivián is of late Quaternary age,[7] it may have formed between 600,000 - 500,000 years ago.[10] Such a dating is supported by fossils found in sediments left by the lake.[5] The existence of Lake Ballivián in the Titicaca basin may coincide with the existence of Lake Escara,[11] and preceded the existence of Lake Minchin.[12] The water levels of Escara were much lower than these of Ballivián, indicating that the Ulloma-Capalla sill did exist at that time.[5] It is possible that waters from Lake Ballivián broke through at Calacoto into the Rio Mauri valley, rapidly cutting down a new valley and draining the lake.[13] The formation of the Rio Desaguadero outlet may have stabilized future lake levels.[14]

A tectonic event shortly before the formation of the lake formed a trough which is now the location of Lake Titicaca.[15] The interglacial Sorata-Choqueyapu I may be contemporaneous to Lake Ballivián,[10] as would be the Saale glaciation in Europe and the Illinoian glaciation in North America.[6]

During the Lake Ballivián episode, pupfish colonized the southern and central Altiplano.[16] The speciation of Biomphalaria snails may have also been influenced by the development of Lake Ballivián.[17] The sponge Balliviaspongia is named after Lake Ballivián.[18]

References

  1. 1 2 Fornari, Risacher & Féraud 2001, p. 269.
  2. 1 2 Fornari, Risacher & Féraud 2001, p. 270.
  3. 1 2 Bills, Bruce G.; de Silva, Shanaka L.; Currey, Donald R.; Emenger, Robert S.; Lillquist, Karl D.; Donnellan, Andrea; Worden, Bruce (15 February 1994). "Hydro-isostatic deflection and tectonic tilting in the central Andes: Initial results of a GPS survey of Lake Minchin shorelines". Geophysical Research Letters. 21 (4): 293. doi:10.1029/93GL03544.
  4. ↑ Bowman, Isaiah (1914). "Results of an Expedition to the Central Andes". Bulletin of the American Geographical Society. 46 (3): 180. doi:10.2307/201641.
  5. 1 2 3 4 Lavenu 1995, p. 83.
  6. 1 2 Clapperton, C.M. (January 1983). "The glaciation of the Andes". Quaternary Science Reviews. 2 (2-3): 120. doi:10.1016/0277-3791(83)90005-7.
  7. 1 2 Servant, Michel (1977-01-01). "Le cadre stratigraphique du plio-quaternaire de l'altiplano des Andes tropicales en Bolivie". Bulletin - AFEQ (in French) (suppl. au 50): 325.
  8. ↑ Jenks, William F. (1956). "PERU". 65: 246. doi:10.1130/MEM65-p215. ISSN 0072-1069.
  9. ↑ Dejoux & Iltis 1992, p. 40.
  10. 1 2 Kroll et al. 2012, p. 1519.
  11. ↑ Fornari, Risacher & Féraud 2001, p. 271.
  12. ↑ Fornari, Risacher & Féraud 2001, p. 279.
  13. ↑ Brüggen, J. (April 1929). "Zur Glazialgeologie der chilenischen Anden". Geologische Rundschau (in German). 20 (1): 3. doi:10.1007/BF01805072.
  14. ↑ Rudolph, William E. (January 1940). "Bolivia's Water-Power Resources". Geographical Review. 30 (1): 53. doi:10.2307/210449.
  15. ↑ Dejoux & Iltis 1992, pp. 13-14.
  16. ↑ Kroll et al. 2012, p. 1525.
  17. ↑ Collado, Gonzalo A.; Méndez, Marco A. (November 2013). "Microgeographic differentiation among closely related species of (Gastropoda: Planorbidae) from the Andean Altiplano". Zoological Journal of the Linnean Society. 169 (3): 648. doi:10.1111/zoj.12073.
  18. ↑ Dejoux & Iltis 1992, p. 297.

Sources

External links

This article is issued from Wikipedia - version of the 10/22/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.