Abstract

ROJAS, Vanessa; BARAHONA, Dione  and  ALVARADO, Guillermo E.. Geomorphology and petrography of ángeles lava flow and The Monte de la Cruz cinder cone, Barva Volcano, Costa Rica. Rev. Geol. Amér. Central [online]. 2017, n.56, pp.17-35. ISSN 0256-7024.  http://dx.doi.org/10.15517/rgac.v0i56.29240.

Monte de la Cruz complex piroclastic cone is located on the southeast footslope of Barva Volcano. This cone produced the Ángeles lava flow (7,3 km, área 12,8 km2). Through geomorphological, petrographical and field studies, two units were recognized: Lower and Upper Ángeles. Petrographically, the Lower Ángeles corresponds with a vesicular andesitic-basaltic lava, with a hypocristalline porphyritic to glomeroporphyritic texture, with phenocrystals of plagioclase, clinopyroxene, orthopiroxene, olivine and opaque crystals. On the other hand, the Upper Ángeles is a vesicular andesitic lava with hypocristalline, glomeroporphyritic to glomeroporphyritic seriate texture, with phenocrystals of plagioclase, clinopyroxene, orthopiroxene, olivine and opaque crystals. Morphologically kipukas and lévees were observed. Regionally the Monte de la Cruz cone along with other minor satellite cones are aligned N19°W over 8,5 km, yielding a possible origin associated with a volcano-tectonic fracture.

Keywords : Cinder cone; Monte de la Cruz; Barva volcano; andesites; Geomorphology.

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