Record details

Title
    The Late Miocene Guacimal Pluton in the Cordillera de Tilarán, Costa Rica: its nature, age and petrogenesis
Author
    Alvarado, Guillermo
    Huapaya, Sofia
    Janoušek, Vojtěch
    Košler, Jan
    Mixa, Petr
    Ulloa, Andrés
    Vondrovicová, Lenka
    Žáček, Vladimír
Language
    anglicky
Publication type
    článek v periodiku
Source title - serial
    Journal of Geosciences
Vol./nr.
    Roč. 56, č. 1
Pages
    29
Year
    2011
Thesaurus term
    granitic rocks, geochemistry, mineralogy, zircon U-Pb age, Guacimal Pluton, Costa Rica, Central American Volcanic Arc
Keyword
    Age
    Cordillera
    Costa
    Guacimal
    Late
    Miocene
    Nature
    Petrogenesis
    Pluton
    Rica
    Tilarán
Abstract (in english)
   The Guacimal Pluton situated in the Cordillera de Tilarán in the NW of Costa Rica forms an oval-shaped body with an exposed surface of 60-70 km2. The pluton intruded into basic volcanic rocks of the Aguacate Group (Miocene-Pliocene) and is surrounded by a aureole of calc-silicate metasomatic rocks. The pluton is mainly formed by monzogranites to granodiorites, which strongly prevail over more basic types. The pluton was emplaced at depth of c. 3 km, crystallized at temperature of c. 760-800 °C under a relatively high oxygen fugacity (1.6-2.1 log units above the NNO buffer) and increased activities of volatiles (H2O, F) upon cooling. The prevailing, felsic rocks of the Guacimal Pluton are high-K calc-alkaline. Laser ablation ICP-MS dating of zircons from two granite samples yielded statistically identical U-Pb ages of 6.3 ? 0.5 and 6.0 ? 0.4 Ma, respectively. The Sr-Nd isotopic compositions are rather primitive (87Sr/86Sr6 = 0.70380-0.70413, e6Nd ~ +7.3 to +7.9).
Contributor
    Česká geologická služba
Contributor code
    ČGS (RIV)
Source format
    R
Import date
    15. 10. 2014