| Journal: | Boletín de la Sociedad Geológica Mexicana |
| Database: | PERIÓDICA |
| System number: | 000388674 |
| ISSN: | 1405-3322 |
| Authors: | Campos Enríquez, José Oscar1 Lermo Samaniego, Javier Francisco2 Antayhua Vera, Yanet Teresa3 Chavacán, Marcos3 Ramón Márquez, Victor Manuel3 |
| Institutions: | 1Universidad Nacional Autónoma de México, Instituto de Geofísica, México, Distrito Federal. México 2Universidad Nacional Autónoma de México, Instituto de Ingeniería, México, Distrito Federal. México 3Universidad Nacional Autónoma de México, Posgrado en Ciencias de la Tierra, México, Distrito Federal. México |
| Year: | 2015 |
| Volumen: | 67 |
| Number: | 2 |
| Pages: | 315-335 |
| Country: | México |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Analítico, descriptivo |
| Spanish abstract | Estudios gravimétricos y sísmicos nos permitieron establecer las características mayores de la estructura cortical somera por debajo de la Sierra de Chichinautzin. La Sierra de Chichinautzin evolucionó sobre rocas calcáreas mesozoicas descansando sobre un basamento metamórfico. Hacia el norte y el sur este basamento se encuentra fallado. En las cuencas de Toluca y de México, sin embargo, las fallas que buzan al norte desplazan el basamento a mayores profundidades (2 a 3 km). En la Plataforma de Morelos, la Boletín de la Sociedad Geológica Mexicana Volumen 67, núm. 2, 2015, p. 315-335 The Aztlán Fault System: control on the emplacement of the Chichinautzin Range volcanism, southern Mexico Basin, Mexico. Seismic and gravity characterization José Oscar Campos-Enríquez1,*, Javier Francisco Lermo-Samaniego2 , Yanet Teresa Antayhua-Vera3 , Marcos Chavacán3 , Victor-Manuel Ramón-Márquez3,4 1 Instituto de Geofísica, Universidad Nacional Autónoma de México, México, D.F., México. 2 Instituto de Ingeniería, Universidad Nacional Autónoma de México, México, D.F., México. 3 Programa de Posgrado de Ciencias de la Tierra, Universidad Nacional Autónoma de México, D.F., Mexico. 4 Facultad de Ingeniería, Benemérita Universidad Autónoma de Puebla, Puebla, México. * ocampos@geofisica.unam.mx MEXICANA A.C. SOCIEDAD GEOLÓGICA 1904 2004 C i e n A ñ o s 316 Campos-Enríquez et al. 1. Introduction The Trans-Mexican Volcanic Belt (TMVB) is a PlioceneQuaternary elongated volcanic province, approximately between the latitudes 19.5° and 21° N, spanning from the Pacific Ocean to the Gulf of Mexico (Figure 1). The most active dacitic-andesitic stratovolcanoes in Mexico are located in it. Also included are cinder cone fields, isolated occurrences of rhyolitic volcanism, large silicic caldera centers, and plateau lava sequences (Mooser, 1972; Demant, 1978, 1981a, 1981b; Negendank et al., 1985; Ferriz and Mahood |
| English abstract | Gravity and seismic studies enabled us to establish the major features of the shallow crustal structure beneath Chichinautzin Range. Accordingly, the Chichinautzin Range evolved above Mesozoic calcareous rocks lying on a metamorphic basement. To the north and south this basement is downfaulted. Nevertheless the north dipping faults downward displace the basement to larger depths (2 to 3 km) in the Mexico and Toluca basins. In the Morelos Basin, the basin is shallower. As block-faulting evolved, the basement edge migrated southwards, thus widening an E-W oriented major depression south of the Mexico Basin. In particular, gravity modeling enabled us to integrate the different faults mapped up to today in and around the Chichinautzin Range into a fault system that can be correlated from the Nevado de Toluca. This system will be referred to collectively as the Aztlán Fault System. The Xicomulco, Aztec (central and major fault) and La Pera faults are featured by seismicity. Orientation and dips obtained from simple and composite mechanisms indicate NW-SE to N-S extension with minor E-W left-lateral movement. In particular, seismicity extends down to the brittle-ductile transition crustal zone (maximum hypocentral depths of about 15 km) but consequently the major faults, considering their length, should reach lower crustal levels (approximately 40 km). This system is a major active fault system of at least 100 km in length and 30 – 40 km in width, with a density of approximately 10 E-W faults in 30 km, and local extension of about 10 %. In conjunction with pre-existing NW-SE and NE-SW faults, this E-W fault system would have intensely fractured the crust beneath the Sierra de Chichinautzin. This high degree of fracturing would have enabled the relatively fast emplacement of large quantities of volcanic material to give rise to the Chichinautzin Range, closing the Mexico Basin to the south. The gravity model shows how |
| Disciplines: | Geociencias |
| Keyword: | Sismología y vulcanología, Falla Aztlán, Sierra Chichinautzin, Volcanismo, Sismicidad, Cuenca de México, México |
| Keyword: | Earth sciences, Seismology and volcanology, Aztlan fault, Sierra Chichinautzin, Volcanism, Seismicity, Basin of Mexico, Mexico |
| Full text: | Texto completo (Ver PDF) |
