Late tertiary volcanic stratigraphy of northern central America

Reynolds, James H.

doi:10.1007/bf02597696

Cited by 40 publications

(32 citation statements)

References 2 publications

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“…Ilopango caldera study area study area (1975) and Reynolds (1980). Schmidt-Thomé (1975) treated in a greater detail geology in the area of the capital San Salvador, including compilation of a geological map on the scale 1 : 15 000 (Centro de Investigaciones Geotécnicas 1987).…”

Section: San Salvador Volcanomentioning

confidence: 99%

“…The NW-SE trending gray dashed lines crossing the San Salvador volcano indicate a zone of the most frequent summit and flank eruptions. Modified after Hernández (2008 (Wiesemann 1975;Bosse et al 1978;Reynolds 1980). The Bálsamo Formation is built by andesite lavas, tuffs and epiclastic volcanic breccias/conglomerates representing remnants of andesite stratovolcanoes.…”

Section: Geological Setting and Lithostratigraphic Unitsmentioning

confidence: 99%

“…Assignment of rocks to the formation might be sometimes questionable. To avoid misunderstanding we respect the view of Reynolds (1980Reynolds ( , 1987 who defined the Cuscatlán Formation as an assemblage of dominantly silicic explosive volcanic activity products associated with evolution of calderas, younger or contemporaneous to the Bálsamo Formation, including reworked counterparts and interstratified and/ or overlying silicic to mafic lavas. In the study area the Cuscatlán Formation rests on rocks of the Bálsamo Formation and along the crest of the Cordillera del Bálsamo.…”

Section: Cuscatlán Formationmentioning

confidence: 99%

“…18) but the radiometric ages of the Bálsamo and Cuscatlán formations in El Salvador have been missing so far. The ages are based solely on the correlation of volcanic formations across the northern Central America (Reynolds 1980) and on the analogy with the SE Guatemala (Reynolds 1987). Therefore, we have dated 30 samples of the Bálsamo and Cuscatlán formations using the conventional K-Ar method.…”

Section: Volcanic Evolution Of the Areamentioning

confidence: 99%

“…Volcanic activity of the Bálsamo Formation in the study area was concluded by formation of very extensive basaltic andesite-andesite Jayaque stratovolcano during the Late Pliocene-Early Pleistocene time. (Reynolds 1980(Reynolds , 1987 commenced during the Early Pleistocene, firstly in the E by Ilopango ignimbrites, later in the W by Jayaque ignimbrites. Jayaque ignimbrites were related to the Jayaque caldera in the central zone of the Jayaque andesite stratovolcano.…”

Section: Evolution Of Volcanic Activitymentioning

confidence: 99%

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Geology and volcanic evolution in the southern part of the San Salvador Metropolitan Area

Lexa¹,

Šebesta²,

Chávez³

et al. 2012

J. Geosci.

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We have carried out geological studies including mapping at the scale 1 : 50 000 in the southern part of the San Salvador Metropolitan Area to support urban planning and natural hazard mitigation. The study area extends over the Cordillera del Bálsamo, marginal fault system and southern part of the Central Graben between the active San Salvador volcano and Ilopango caldera. It represents a segment in the Central American Volcanic Front. Volcanic rocks of the Late Miocene to recent age, classified as the Bálsamo, Cuscatlán and San Salvador formations, occur in the area. Remnants of two large basaltic andesite to andesite stratovolcanoes, Panchimalco and Jayaque, represent the Bálsamo Formation. They show periclinal dips and facies zoning from lava flows and coarse epiclastic volcanic breccias of the proximal zone through epiclastic volcanic breccias/conglomerates of the medial zone to epiclastic volcanic conglomerates and sandstones of the distal zone. Their ages are 7.2-6.1 Ma and 2.6-1.5 Ma respectively. The Cuscatlán Formation comprises the Jayaque and Santo Tomás calderas, the andesitic-dacitic Ilopango and Jayaque ignimbrites (1.9-1.4 Ma) in the SW and SE parts of the area, the Ilopango andesitic volcano (1.5-0.8 Ma), the Loma Larga basaltic volcano (0.8-0.5 Ma), the Planes de Renderos caldera, the dacite-andesite San Jacinto extrusive domes and effusive cone (0.4-0.25 Ma), the San José tuff/scoria cone, the Ilopango caldera extrusive domes (0.25-0.05 Ma), the Antiguo Cuscatlán scoria cone (0.2-0.08 Ma) and older tephra deposits of the Coatepeque and Ilopango calderas exposed along marginal faults of the Central Graben. The San Salvador Formation occurs as tephra cover along the crest of the Cordillera del Bálsamo where it rests on laterites atop the Bálsamo Formation and in the Central Graben. Tephra units belong to the Coatepeque caldera (Arce and Congo), San Salvador volcano (Apopa, G1 and G2) and Ilopango caldera (Tierra Blanca 1-4) spanning 70-1 ka. Tephra units are separated by palaeosols and aeolian dusty deposits.Las amenazas naturales afectan al territorio de El Salvador en toda su extensión de manera constante. Se ha llevado a cabo un mapeo geológico en la parte Sur del Área Metropolitana de San Salvador (AMSS), asimismo se han evaluado las amenazas naturales potenciales que pueden afectar a la zona. El área de estudio se extiende sobre la Cordillera del Bálsa-mo, el sistema de fallas marginales y en la parte Sur del Graben Central entre los volcanes activos de San Salvador y la Caldera de Ilopango; representando un segmento del frente volcánico de Centro América. Las rocas volcánicas del Mioceno tardío hasta de edad reciente que pertenecen a las Formaciones Bálsamo, Cuscatlán y San Salvador conforman la geología del área. Los remanentes de dos extensos estratovolcanes basálticos-andesíticos hasta andesíticos, Panchimalco y Jayaque, representan la Formación Bálsamo. Estos presentan un buzamiento periclinal y zonas con facies que van desde flujos de lava y brechas epiclásticas volcánicas gruesas de ...

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Section: San Salvador Volcanomentioning

confidence: 99%

Section: Geological Setting and Lithostratigraphic Unitsmentioning

confidence: 99%

Section: Cuscatlán Formationmentioning

confidence: 99%

Section: Volcanic Evolution Of the Areamentioning

confidence: 99%

Section: Evolution Of Volcanic Activitymentioning

confidence: 99%

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