Cabana (ancient lake)

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]

Lake Cabana is an ancient lake in the Altiplano.

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][10] 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.[11] A phase of tectonic extension in the Titicaca basin may have favoured the formation of this lake.[12] The existence of this lake may have facilitated the diversification of Heleobia snails, but increased speciation only occurred during the subsequent Ballivian episode.[13]

References

1. 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. Wirrmann et al. 1992, p. 40.
3. Wirrmann et al. 1992, p. 10.
4. 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. Schäbitz, F.; Liebricht, H. (1999). "Zur Landschaftsgeschichte der Halbinsel Copacabana im peruanisch-bolivianischem Grenzbereich des Titicacagebietes". Beiträge zur quartären Landschaftsentwicklung Südamerikas. Festschrift zum 65. Geburtstag von Professor Dr. Karsten Garleff. Bamberger geographische Schriften (in German). Bamberg. p. 117. OCLC 602709757.
10. Newell 1949, p. 82.
11. Newell 1949, p. 85.
12. Wirrmann et al. 1992, p. 12.
13. 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): 1517–30. doi:10.1002/ece3.280. PMC 3434920. PMID 22957159.

Sources

• Newell, Norman D. (1949). "Geology of the Lake Titicaca Region, Peru and Bolivia". GSA Memoirs. 36. Geological Society of America. pp. 1–124. doi:10.1130/mem36-p1.
• 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.