For the first time this century a seasonal ice cover was observed at the summit. The ice cover was seen on the N and W faces from February 1993 through the end of May. The primary source of water for Puebla is runoff from Malinche; it is not known what effect the development of an ice cap will have on the water supply. Glacial deposits have been identified on the NE flanks of the volcano. Seismicity has been monitored daily from a station at Puebla University since 1986, but no events have been detected.

Reference. von Erfa, A., 1979, Geología de la Cuenca Puebla Tlaxcala: Comunicaciones No. 5, Fundación Alemana para la Investigación Científica.

Geological Summary. La Malinche is an eroded stratovolcano, cut by deep canyons, NE of the city of Puebla. It occupies an isolated position between the Popocatépetl-Iztaccíhuatl and Orizaba-Cofre de Perote volcanic ranges. Much of the andesitic-dacitic volcano was constructed during the Pleistocene, and the summit exhibits evidence of glacial erosion. Although relatively unstudied, research has identified Holocene tephra layers that originated from Volcán la Malinche. Several cones and explosion craters, at least one of Holocene age, are found on the flanks; one of the most prominent of these is the Xalapaxco maar complex on the lower ENE flank. Holocene lahars associated with an eruption about 3,100 years ago reached the Puebla basin and affected communities there.

Information Contacts: Alejandro Rivera Dominguez, Dept de Ciencias de la Tierra, Univ Autonoma de Puebla, Apartado 1572, C.P. 7200, Puebla, México.