Artículo

A synthesis and comparison of the geochemistry of volvanic rocks of the sierra madre occidental and mexican volcanic belt

Cameron, M.; Spaulding, K.; Cameron, K. L.

Instituto de Geofísica, UNAM, publicado en Geofísica Internacional, y cosechado de Revistas UNAM

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Procedencia del contenido

Entidad o dependencia
Instituto de Geofísica, UNAM
Revista
Repositorio
Contacto
Revistas UNAM. Dirección General de Publicaciones y Fomento Editorial, UNAM en revistas@unam.mx

Cita

Campillo, M., et al. (1987). A synthesis and comparison of the geochemistry of volvanic rocks of the sierra madre occidental and mexican volcanic belt. Geofísica Internacional; Vol. 26 No. 1, 1987. Recuperado de https://repositorio.unam.mx/contenidos/42091

Descripción del recurso

Autor(es)
Cameron, M.; Spaulding, K.; Cameron, K. L.
Tipo
Artículo de Investigación
Área del conocimiento
Físico Matemáticas y Ciencias de la Tierra
Título
A synthesis and comparison of the geochemistry of volvanic rocks of the sierra madre occidental and mexican volcanic belt
Fecha
2013-04-21
Resumen
The Cenozoic-Recent volcanic rocks of mainland Mexico are largely confined to three provinces: the Sierra Madre Occidental (SMO), the Trans-Mexican Volcanic Belt (MVB), and the Eastern Alkalic province. The first two provinces are dominated by cale-alkalic rock series, but minor amounts of contemporaneous alkaline rocks are also present. The third province is comprised largely of alkaline volcanics.Comparison of the two calc-alkalic provinces reveals that each has distinct characteristics. The mid-Tertiary SMO volcanics are comprised largely of rhyolitic ignimbrites whereas the MVB is characterized by prominent neovolcanic centers that are primarily andesitic in composition. Cale-alkalic andesites from the western MVB (e.g., Ceboruco) have chemical characteristics that are distinct from andesites of the central MVB (e.g., Colima, Paricutín, Orizaba, Jorullo, Popocatépetl, Toluca). The andesites of Ceboruco have higher Na2O + K2O, K2O, Na2O, TiO2 , P2O5 , Ba, La, and (Ce/Yb)N and lower CaO, MgO, Cr, and Ba/La than andesites of the central MVB. Calc-alkalic andesites from the northern SMO (Batopilas area) and from the central MVB have similar total alkalies, K2O, Na2O, CaO, Sr, Zr and (Ce/Yb)N. The SMO andesites also have lower MgO and K/Rb and higher FeO*, TiO2, Rb, Th, La, and Y than calc-alkalic rocks of the central MVB. Initial Sr isotopic ratios of compositionallyintermediate MVB volcanics are restricted to the range 0.7035 - 0.7047 whereas the intermediate-felsic volcanics of the SMO have Sr[ ranging between 0.7033 and 0.7614. Such ratios indicate significant interaction of parental magmas with old radiogenic crust for the SMO volcanics, but relatively minor, if any, interaction with magmas parental to the MVB volcanics. Limited Nd isotopic data for MVB calc-alkalic volcanics (Colima, Los Humeros, Paricutín and La Primavera) generally have εNd greater than Bulk Earth (up to +5 to +6). Volcanics of the northern SMO (Batopilas area) and southeastern Chihuahua have εNd within ± 2.5units of Bulk Earth.Evolution of the rock suites at individual eruptive centers appears to have been controlled largely by crystal fractionation. Other processes operative at the same time may include magma mixing and crustal assimilation (the latter especially in the SMO). The nature of the source regions for parental magmas of volcanics in both the MVP and SMO-SEC areas has yet to be addressed in a comprehensive manner.
Idioma
spa
ISSN
0016-7169

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