%0 Journal Article
%T Geolog赤a y geoqu赤mica de las lavas pleistoc谷nicas del estratovolc芍n Telap車n, Sierra Nevada, M谷xico
%A Garc赤a-Tovar
%A Gloria P.
%A Mart赤nez-Serrano
%A Raymundo G
%J Revista mexicana de ciencias geol車gicas
%D 2011
%I Universidad Nacional Aut車noma de M谷xico
%X the telap車n stratovolcano belongs to the northern part of the sierra nevada, in the central-eastern part of the trans-mexican volcanic belt. geologic, stratigraphic, and geochemical studies as well as k-ar age determinations were carried out in this volcano formed by dome structures, lava flows and pyroclastic deposits. the lithology was grouped into two volcanic events: an andesitic-dacitic lower volcanic event that was emplaced between 1.03 ㊣ 0.02 and ca.0.65 ma, and a dacitic-rhyolitic upper volcanic event emplaced between ca.0.65 ma to ca.35,000 years ago. the summit of the volcano (4,060 m a.s.l.) is occupied by a 274, 000 years old (k-ar date) dacitic lava flow. block and ash flow pyroclastic deposits and pumice fall deposits ca. 35,000 years old crop out on its flanks. the new k-ar ages indicate that the volcanic activity of the telap車n volcano was coeval to the activity in the sierra nevada. phenocrystals of the porphyritic lava flows show evidence of disequilibrium and magma-mixing. the sio2 vs. alkalis diagram shows that most rocks are classified as basaltic andesite, andesite, dacite and rhyolite (53 - 78 wt.% of sio2), following a calc-alkaline trend. the trace element patterns are similar for all samples indicating a common magmatic source. these patterns display enrichment in the large-ion lithophile elements (lile: cs, rb, ba and k) and pb relative to the high-field-strength elements (hfse: nb, ta). chondrite-normalized ree patterns display light rare earth elements enrichment (la-sm) with respect to the heavy rare earth elements (eu-lu), which have flat patterns. these chemical characteristics are typical of subduction-related volcanic arcs, where the lil elements could be provided by dehydration of the subducted plate into a depleted mantle. crystal fractionation processes from a parental basaltic andesite magma can explain the lithological and geochemical variations of the volcanic rocks. however, magma mixing and assimilation processes modified th
%K volcanism
%K geochemistry
%K k-ar ages
%K pleistocene
%K telap車n volcano
%K sierra nevada
%K mexico.
%U http://www.scielo.org.mx/scielo.php?script=sci_abstract&pid=S1026-87742011000200011&lng=en&nrm=iso&tlng=en