%0 Journal Article
%T Petrology and geochemistry of the Tacan¨¢ Volcanic Complex, Mexico-Guatemala: Evidence for the last 40 000 yr of activity
%A J. C. Mora
%A J. L. Mac¨ªas
%A A. Garc¨ªa-Palomo
%A J. L. Arce
%J Geof¨ªsica internacional
%D 2004
%I Universidad Nacional Aut¨®noma de M¨¦xico
%X The Tacan¨¢ Volcanic Complex (TVC) on the border of Mexico and Guatemala rises above Mesozoic metamorphic and Tertiary plutonic and volcanic rocks. The TVC consists of three volcanic edifices which, from NE-to SW, are named Chichuj, Tacan¨¢, and San Antonio. Chichuj volcano is constituted mainly of andesitic lava flows (59-63 wt.% SiO2). Tacan¨¢ volcano is composed of basaltic-andesite lava flows (56-61 wt.% SiO2), and andesitic and dacitic domes (61-64 wt.% SiO2), surrounded by fans of block-and-ash flow deposits of 38 000, 28 000, and 16 000 yr BP with andesitic juvenile clasts (60-63 wt.% SiO2). San Antonio volcano is built of lava flows, andesitic and dacitic domes (58-64 wt.% SiO2), and one block-and-ash flow deposit dated 1,950 yr BP. The isotope ratios of the TVC andesites varies from 0.70455 to 0.70459 87Sr/86Sr and 0.51275 to 0.51280 143Nd/144Nd. A mafic enclave has ratios of 0.70441 for 87Sr/86Sr and 0.51282 for 143Nd/144Nd. The rocks belong to the sub-alkaline suite and follow the characteristic trend of calc-alkaline rocks, with medium-K content and negative anomalies of Nb, Ti, and P, and enrichment in LREE as is typical of orogenic zones.
%K Andesitic volcanism
%K stratovolcano
%K Tacan¨¢ Volcanic Complex
%K Central American volcanoes
%U http://www.geofisica.unam.mx/unid_apoyo/editorial/publicaciones/investigacion/geofisica_internacional/anteriores/2004/03/Mora.pdf