El volcan La Joya, estados de Queretaro y Guanajuato; un estratovolcan miocenico de Cinturon Volcanico Mexicano. La Joya Volcano, states of Queretaro and Guanajuato; a Miocene stratovolcano of the Mexican volcanic belt
Valdez-Moreno, Gabriel; Aguirre-Diaz, Gerardo de Jesus; Lopez-Martinez, Margarita (1998) El volcan La Joya, estados de Queretaro y Guanajuato; un estratovolcan miocenico de Cinturon Volcanico Mexicano. La Joya Volcano, states of Queretaro and Guanajuato; a Miocene stratovolcano of the Mexican volcanic belt. Revista Mexicana de Ciencias Geologicas, vol.15, no.2, pp.181-197, 1998
| Authors | Valdez-Moreno, Gabriel; Aguirre-Diaz, Gerardo de Jesus; Lopez-Martinez, Margarita |
|---|---|
| Year | 1998 |
| Title | El volcan La Joya, estados de Queretaro y Guanajuato; un estratovolcan miocenico de Cinturon Volcanico Mexicano. La Joya Volcano, states of Queretaro and Guanajuato; a Miocene stratovolcano of the Mexican volcanic belt |
| Source | Revista Mexicana de Ciencias Geologicas, vol.15, no.2, pp.181-197, 1998 |
| Book editors | Aguirre-Diaz, Gerardo de Jesus |
| Publisher | Universidad Nacional Autonoma de Mexico, Instituto de Geologia, Coyoacan, Mexico MEX |
| ISSN | 1026-8774 |
| GeoRef | 2000-059329 |
| Keywords | Cenozoic; dacitic composition; domes; explosive eruptions; Guanajuato Mexico; igneous rocks; ignimbrite; La Joya; lava; Mexican volcanic belt; Mexico; Miocene; Neogene; pumice; pyroclastics; Queretaro Mexico; stratovolcanoes; Tertiary; tuff; viscosity; volcanic rocks; volcanoes |
Abstract
La Joya stratovolcano is located 20 km NNW of Queretaro city, just at the northern end of the NW-oriented Taxco-San Miguel de Allende fault system. La Joya, with an super 39 Ar/ super 40 Ar age of 9.9+ or -0.4 Ma, is one of the four stratovolcanoes of middle Miocene age 9-11 Ma located in the northern margin of the Mexican Volcanic Belt MVB, that include Palo Huerfano, San Pedro, and El Zamorano. These volcanoes are among the oldest stratovolcanoes in the MVB. La Joya overlies a 10.6+ or -0.5 Ma super 39 Ar/ super 40 Ar andesite and is overlain by 6.2+ or -0.6 Ma mafic lavas of a lava-plateau volcanic field south of it. The volcanic evolution of La Joya volcano includes: 1 Emplacement of El Maguey andesitic dome, that predates the volcano, and crops out in the WNW part of it. 2 Explosive eruptions that formed La Loma tuff, including pumice fall deposits and an ignimbrite only exposed in the proximity of the volcano. 3 Eruption of Los Rico andesite, a succession of superimposed lava flows that forms lobes with a short distribution, but over 100-m thick. 4 Eruption of dacitic lava flows La Carbonera, La Joya, and Pinalillo dacites, which evolved from orthopyroxene-bearing lavas to hornblende-rich lavas. They have the aspect of coulees sensu lato associated to exogenous domes. After finishing the activity of the volcano, an erosional circus 5 km in diameter was formed in the summit of the volcano. La Joya volcano has characteristics of both a stratovolcano and an exogenous lava dome. The lavas probably had a high viscosity in the andesitic-dacitic range of composition, and the pyroclastic products indicate an important early explosive event. Comparing the characteristics of La Joya with the El Zamorano and Palo Huerfano volcanoes, similarities in the volcanic style, composition and physical aspect of the products can be recognized.