Morfología y reología cuantitativa de la fase efusiva de los volcanes monogenéticos Melón, Mina, Tzinzimacato grande y Tzinzimacato Chico, localizados al occidente de la ciudad de Morelia, México.

Abstract

Four monogenetic volcanoes erupted during the last 100 ka (Late-Pleistocene), west of the city of Morelia (Mexico), in the central-eastern part of the Michoacán-Guanajuato Volcanic Field, located in the central region of the Trans-Mexican Volcanic Belt. These include four scoria cones (Melón, Mina, Tzinzimacato Grande and Tzinzimacato Chico) including lava flows associated with the material emitted during their effusive phase. From the study of stratigraphic relationships in the field and geological mapping, the eruptive chronology was determined. Subsequently, based on the analysis of the morphological (flow dimensions) and petrographic characteristics, the eruptive parameters (effusion rate and eruption time) and the rheology of the lavas were estimated. The results indicate that the most viscous lavas were those emitted by the Tzinzimacato Grande and Chico volcanoes; 7.35x109-2.89x109 Pa-s respectively, at average temperatures of 1061-1115 C°, the most voluminous eruption was the one emitted the Mina volcano, with an effusion rate of 2.4 m3/s and a total duration of approximately 1.5 years. Although the total volume emitted by Melón volcano is not as large, the data revealed a high effusion rate, probably due to a more mafic composition of its lavas.