Contributions to Mineralogy and Petrology

, 167:1006

Petrogenesis and geodynamic significance of silicic volcanism in the western Trans-Mexican Volcanic Belt: role of gabbroic cumulates

  • Chiara Maria Petrone
  • Teresa Orozco-Esquivel
  • Luca Ferrari
Original Paper

DOI: 10.1007/s00410-014-1006-6

Cite this article as:
Petrone, C.M., Orozco-Esquivel, T. & Ferrari, L. Contrib Mineral Petrol (2014) 167: 1006. doi:10.1007/s00410-014-1006-6

Abstract

In the western Trans-Mexican Volcanic Belt voluminous silicic volcanism has been associated with the rifting of the Jalisco block from mainland Mexico. Rhyolitic volcanism started at 7.5 Ma after a major pulse of basaltic volcanism aged 11–8.5 Ma associated with slab detachment. This was followed by a second period, between 4.9 and 2.9 Ma, associated with rhyolitic domes and ignimbrite coexisting with basaltic volcanism. The similarity in rare earth element contents between basalts and rhyolites excludes a simple liquid line of descent. The low Ba and Sr contents and the ferroan character of the rhyolites suggest extensive fractional crystallization. Late Miocene–early Pliocene rhyolite Sr isotope values are only slightly more radiogenic than the basalts, whereas Nd isotope ratios are indistinguishable. We successfully modelled the 7.5–3 Ma silicic magmatism as a result of partial melting of crustal gabbroic complexes that we infer to have formed in the mid-lower crust due to the high-density Fe-enriched composition of the late Miocene basaltic volcanism. Slab rollback since ~7.5 Ma favoured decompression melting and arrival of additional mafic magmas that intruded in the lower crust. These basalts heated and melted the gabbroic complexes forming the silicic magmas, which subsequently underwent assimilation and fractional crystallization processes. The first silicic pulse was emplaced during a period of low tectonic activity. Extensional faulting since the Pliocene favours the eruption of both silicic magma and lesser amount of mafic lavas.

Keywords

Silicic–bimodal volcanismFerroan magmaLow-Sr rhyolitesTholeiitic trendGabbroic cumulates meltingTrans-Mexican Volcanic Belt

Supplementary material

410_2014_1006_MOESM1_ESM.pdf (120 kb)
Supplementary material 1 (PDF 119 kb)
410_2014_1006_MOESM2_ESM.pdf (126 kb)
Supplementary material 2 (PDF 126 kb)
410_2014_1006_MOESM3_ESM.pdf (124 kb)
Supplementary material 3 (PDF 123 kb)
410_2014_1006_MOESM4_ESM.pdf (178 kb)
Supplementary material 4 (PDF 177 kb)
410_2014_1006_MOESM5_ESM.pdf (1.3 mb)
Supplementary material 5 (PDF 1301 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Chiara Maria Petrone
    • 1
  • Teresa Orozco-Esquivel
    • 2
  • Luca Ferrari
    • 2
  1. 1.Department of Earth SciencesThe Natural History MuseumLondonUK
  2. 2.Centro de GeocienciasUniversidad Nacional Autónoma de MéxicoQuerétaroMexico