Cabana (ancient lake)

Lake Cabana is an ancient lake in the Altiplano.

The lake reached a water level of 3,900 metres (12,800 ft) over the central and northern Altiplano,[1] 90 metres (300 ft) above the current lake levels of Lake Titicaca.[2] The Capalla-Ulloma sill, which separates the Altiplano into a northern and southern basin,[3] did not exist at that time and it did not split up the Cabana lake body. It left deposits reaching thicknesses of 50 metres (160 ft) of thickness;[4] they have been found on the western and eastern sides of the basin.[2] Erosion platforms and terraces covered with gravels[5] and other wave cut structures are remnants of Lake Cabana.[6]

In 1984, this lake was named by a group of researchers.[7] Other ancient lakes on the Altiplano are Lake Mataro, Lake Ballivian, Lake Minchin and Lake Tauca.[8] An erosion surface at 3,900 metres (12,800 ft) elevation and associated clays were formerly attributed with Ballivián[9] but today shorelines at that elevation are instead associated with Cabana.[1]

The lake existed about 1 million years ago. It was preceded by Lake Mataro and succeeded by Lake Escara and Lake Ballivian, the latter in the north and the former in the south.[1] The Kaluyo glaciation preceded the formation of Lake Cabana,[4] earlier it was believed that the 3,900 metres (12,800 ft) high formations predated any glaciation.[10] A phase of tectonic extension in the Titicaca basin may have favoured the formation of this lake.[11] The existence of this lake may have facilitated the diversification of Heleobia snails, but increased speciation only occurred during the subsequent Ballivian episode.[12]

References

  1. 1 2 3 Wirrmann, Denis; Mourguiart, Philippe (May 1995). "Late Quaternary Spatio-temporal Limnological Variations in the Altiplano of Bolivia and Peru". Quaternary Research. 43 (3): 346. doi:10.1006/qres.1995.1040.
  2. 1 2 Wirrmann et al. 1992, p. 40.
  3. ↑ Wirrmann et al. 1992, p. 10.
  4. 1 2 Wirrmann et al. 1992, p. 8.
  5. ↑ Newell 1949, p. 91.
  6. ↑ Newell 1949, p. 92.
  7. ↑ Fornari, Michel; Risacher, François; Féraud, Gilbert (August 2001). "Dating of paleolakes in the central Altiplano of Bolivia". Palaeogeography, Palaeoclimatology, Palaeoecology. 172 (3–4): 270. doi:10.1016/S0031-0182(01)00301-7.
  8. ↑ E. Gierlowski-Kordesch; K. Kelts (23 November 2006). Global Geological Record of Lake Basins:. Cambridge University Press. p. 405. ISBN 978-0-521-03168-4.
  9. ↑ Newell 1949, p. 82.
  10. ↑ Newell 1949, p. 85.
  11. ↑ Wirrmann et al. 1992, p. 12.
  12. ↑ Kroll, Oliver; Hershler, Robert; Albrecht, Christian; Terrazas, Edmundo M.; Apaza, Roberto; Fuentealba, Carmen; Wolff, Christian; Wilke, Thomas (July 2012). "The endemic gastropod fauna of Lake Titicaca: correlation between molecular evolution and hydrographic history". Ecology and Evolution. 2 (7): 1525. doi:10.1002/ece3.280.

Sources

  • Newell, Norman D. (1949), "36 : Geology of the Lake Titicaca Region, Peru and Bolivia", Geological Society of America Memoirs, Geological Society of America Memoirs, Geological Society of America, 36, pp. 1–124, doi:10.1130/mem36-p1, retrieved 2018-06-10, (Subscription required (help))
  • Wirrmann, Denis; Ybert, Jean-Pierre; Mourguiart, Philippe; Ybert, J.-P. (1992-01-01). Dejoux, C.; Iltis, A., eds. Lake Titicaca. Monographiae Biologicae. Springer Netherlands. pp. 40–62. doi:10.1007/978-94-011-2406-5_3. ISBN 9789401050616.

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