Prieto, Cerro

sopka (bez známé erupce za posledních ~12 000 let), Mexico, Eastern Pacific Volcanic Regions

Kde

Mexico, Eastern Pacific Volcanic Regions

Typ (GVP)

Lava dome

Nadmořská výška

223 m

Poloha

32,418°, -115,305°

The Cerro Prieto Volcanic Complex is the surface manifestation of the Cerro Prieto Geothermal Field, and 90 km NW of the Gulf of California and 35 km S of the city of Mexicali. As described by García-Sánchez et al. (2017), the "geothermal field and the Salton Sea in the USA sit in a pull-apart basin that belongs to the trans-tensional tectonic zone that includes the San Andreas Fault system and the Salton Trough basin to the NW and the East Pacific Rise to the SE." Although the only obvious volcanic feature is the small Cerro Prieto dome complex with a 200-m-wide crater at the NE end, the complex, as defined by García-Sánchez et al. (2017), "consists of seven stratigraphic units emplaced in a brief time span around 78–81 ka. Its activity began with the extrusion of a dacitic lava that came into contact with water-saturated sediments, causing brecciation of the lava. The activity continued with the emplacement of dacitic domes and a dyke that were destroyed by a phreatic explosion emplacing a lithic-rich breccia. This phreatic explosion formed a 300-m-wide and 40-m deep circular crater. The activity then migrated ~650 m to the SW where three dacitic lava domes were extruded and ended with the emplacement of a fissure-fed lava flow." Ages around 100,000 years BP (possibly up to 10,000 years) were reported by de Boer (1979) and Reed et al. (1984), and Cucupas Indian legends described a monster that covered the land with hot rocks, which grew through the soil and emitted fire tongues. Later work by García-Sánchez et al. (2017) presented "two 40Ar/39Ar whole-rock ages reported by Macías et al. (2011) in an internal unpublished report for CFE [with recalculated ages] of 78 ± 17 ka for the brecciated dacitic lava and 81 ± 13 ka for the dacitic dyke."

Text: Smithsonian Global Volcanism Program.

Údaje o sopce: Smithsonian Global Volcanism Program. Další sopky a průduchy.