Plio-Pleistocene volcanic history of the Ahuachapán geothermal system, El Salvador: The Concepcion De Ataco Caldera

Scrubbing process and chemical equilibria controlling the composition of light hydrocarbons in natural gas discharges: An example from the geothermal fields of El Salvador

“…It lies within the 6‐km‐wide Pleistocene caldera of Concepcion de Ataco that is part of the Apaneca volcanic complex (also known as the Cuyanausol Range) consisting of roughly E‐W oriented Pleistocene and Holocene stratovolcanoes. The post‐caldera cones of Cerro El Aguila (2036 m a.s.l., the highest peak of the complex) and Cerro Los Naranjos volcanoes, at the eastern end of the Apaneca Range, and the young craters of Laguna Verde stratovolcano may have been active during the Holocene [ Gonzales Partida et al , 1997]. The volcanic sequence of the Concepcion de Ataco caldera, whose volume approaches about 63 km 3 [ Gonzales Partida et al , 1997], is composed by basaltic andesites to dacitic‐ryolitic [ Aumento et al , 1982] alternated layers of tuff, lava and pyroclastic sequences [ Montalvo , 1994].…”

“…The post‐caldera cones of Cerro El Aguila (2036 m a.s.l., the highest peak of the complex) and Cerro Los Naranjos volcanoes, at the eastern end of the Apaneca Range, and the young craters of Laguna Verde stratovolcano may have been active during the Holocene [ Gonzales Partida et al , 1997]. The volcanic sequence of the Concepcion de Ataco caldera, whose volume approaches about 63 km 3 [ Gonzales Partida et al , 1997], is composed by basaltic andesites to dacitic‐ryolitic [ Aumento et al , 1982] alternated layers of tuff, lava and pyroclastic sequences [ Montalvo , 1994]. The tectonic structure is controlled by E‐W, associated to the Central American graben, and NE‐SW trending fault systems.…”

“…The tectonic structure is controlled by E‐W, associated to the Central American graben, and NE‐SW trending fault systems. The geothermal field, which is characterized by numerous hot springs, bubbling pools and fumaroles [ Gonzales Partida et al , 1997], is the largest one under exploitation in El Salvador. Its heat source seems to be related to the presence of an andesite‐basalt magmatic chamber (0.1 Ma) located at the depth of 9 km [ Jacobo , 2003].…”

“…Its heat source seems to be related to the presence of an andesite‐basalt magmatic chamber (0.1 Ma) located at the depth of 9 km [ Jacobo , 2003]. Geophysical measurements suggest that Ahuachapan and Chipilapa can be regarded as two distinct hydrothermal systems [ Romo et al , 1997], separated by a hydrological barrier resulting by an uplift structure [ Gonzales Partida et al , 1997]. Nevertheless, the chemical and isotopic features of the geothermal fluids of the two areas seem to indicate the existence of a common deep reservoir.…”

Evidence for serpentinite fluid in convergent margin systems: The example of El Salvador (Central America) arc lavas

“…In the Ahuachapán area, several strato‐volcanoes formed over a local volcanic basement (i.e., ES 43: 248 ± 67 ka [ Agostini et al , 2006]) and were dissected by a major caldera event related to the emission of abundant pyroclastic products [ Gonzales Partida et al , 1997]. An 40 Ar‐ 39 Ar age of 127 ± 20 ka was obtained for a pre‐caldera lava.…”