Tres Virgenes

Tres Virgenes is a complex of volcanoes located in northern Baja California Sur state, on the Baja California Peninsula in northwestern Mexico. It is composed of three volcanoes, aligned northeast-southwest, with El Viejo, the oldest, to the northeast, El Azufre in the middle, and the youngest, El Virgen, to the southwest. The time of the last eruption of the volcanoes in the complex was of El Virgen, but the exact date is disputed. A map drawn by the missionary Ferdinand Konščak contains a reference to an eruption in 1746Ives, Ronald, "Dating of the 1746 Eruption of Tres Virgenes Volcano, Baja California Del Sur, Mexico," Geological Society of America Bulletin, v. 73, pp. 647-648, May 1962.] . Radiometric datings, however, do not agree with this. A charcoal fragment found in a volcanic deposit was dated at approximately 6515 years before presentCapra et al., "Holocene plinian eruption of La Virgen Volcano, Baja California, Mexico," Journal of Volcanology and Geothermal Research, Issue 80 pp. 239–266, 1998.] . A basaltic lava flow, which must be younger than the actual eruption, was dated at approximately 24 thousand years B.P.Hausback and Abrams, "Plinian eruption of La Virgen Tephra, Volcán Las Tres Virgenes, Baja California Sur, Mexico", American Geophysical Union, Issue 77, pp. 813–814, 1996.] which agrees with a dating of La Virgen tephra that yielded an age of approximately 36 thousand years B.P. for the eruptionSchmitt et al., "Eruption and magma crystallization ages of Las Tres Vírgenes (Baja California) constrained by combined 230Th/238U and (U–Th)/He dating of zircon," Journal of Volcanology and Geothermal Research, Issue 158, pp. 281–295, 2006.] .

ee also

*Mountain peaks of México
*Mountain peaks of North America

References

External links

* [http://www.volcano.si.edu/world/volcano.cfm?vnum=1401-01= Global Volcanism Program: Tres Virgenes]
* [http://www.geofisica.unam.mx/vulcanologia/volcanes/tresvirgenes.html Tres Virgenes Volcanic Complex]