%0 Journal Article
%T Din芍mica eruptiva de la "P車mez Ezequiel Montes" en la caldera Amazcala, centro de M谷xico
%A Hern芍ndez
%A Javier
%A Carrasco-N迆ˋez
%A Gerardo
%A Aguirre-D赤az
%A Gerardo
%J Revista mexicana de ciencias geol車gicas
%D 2009
%I Universidad Nacional Aut車noma de M谷xico
%X the p車mez ezequiel montes (pem) is a late miocene sequence of plinian fallout deposits associated with the formation of the amazcala caldera, 30 km ne of quer谷taro city in central mexico. the p車mez ezequiel montes is a stratified sequence of fallout deposits interlayered with sporadic thin pyroclastic surge layers, and some horizons of reworked material. the whole sequence is very thick (32 m in the se type locality) and widely distributed along two main dispersal axes, oriented to the sw and the se, with respect to the caldera centre. deposits are dominated by gray pumice of rhyolite composition, with minor quantities of lithic clasts; such composition is fairly homogeneous along the whole sequence. both the size of the pumice fragments and the thickness of the identified units diminish to the sw and se and the isopach maps confirm that the p車mez ezequiel montes was emitted from the amazcala caldera. the physical parameters obtained from the study of 14 sections and correlation of unit a (selected by its widespread distribution) reveal that this unit in the sw lobe represents an event associated to a 23-km height plinian eruptive column with an exit velocity of about 100 m/s. this eruptive column produced a widespread pumice fallout with a minimal volume of 2.6 km3 and a mass of 1.45℅1012 kg. the mass discharge rate estimated for this eruptive column is of ~6℅107 kg/s.
%K explosive volcanism
%K plinian eruption
%K amazcala caldera
%K mexico.
%U http://www.scielo.org.mx/scielo.php?script=sci_abstract&pid=S1026-87742009000200016&lng=en&nrm=iso&tlng=en