Abstract

VAZQUEZ SELEM, Lorenzo. Glaciaciones del cuaternario tardío en el volcán Téyotl, Sierra Nevada. Invest. Geog [online]. 1991, n.22, pp.25-45. ISSN 2448-7279.

Geomorphological and stratigraphical evidences of three glaciations have been recognized over the late Pleistocene lavas that formed the Téyotl volcano (4 660 m), located oil the northern side of the Iztaccíhuatl volcanic complex (ca. 19º N, Central Mexico). The oldest one, T1, deposited large moraines whose terminal positions lie around 3 400 3 200 m. These moraines were covered by a layer of air-fall pumice originated at the Popocatépetl volcano prior to 12 900 yr B. P. (probably ca. 14 500 yr B. P.). Terminal moraines of the second glaciation, T2, lie between 3 800 and 4 000 m and were not covered by the above mentioned pumice. They were probably formed by the end of the Pleistocene. The latest, glaciation, T3, covered some slopes above 4 100 - 4 200 m and was strongly controlled by local relief conditions. Some rock glaciers (at present inactive) make evident the transition to periglacial conditions at the end of the event. An holocenic age (which in certain cases might not go beyond a few centuries or decades) is suggested for T3 deposits on the basis of its morphology. A comparison of the Téyotl glacial sequence with those from other mountains of Central Mexico proposed by S. White and by K. Heine, allows some correlations. However, this comparison reveals several problems whose solution lies on tephrachronology and absolute dating.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )