TY - JOUR
T1 - Origin of bimodal rear-arc volcanism, Trans-Mexican Volcanic Belt eastern sector
T2 - Geochemical and isotopic evidence from the Quaternary Xihuingo-La Paila Volcanic Field
AU - Martínez-Serrano, Raymundo G.
AU - Valadez-Cabrera, Sac Nicté
AU - Roberge, Julie
AU - Cristiani-Solís, Carlos G.
N1 - Publisher Copyright:
© 2022 John Wiley & Sons Ltd.
PY - 2022/5
Y1 - 2022/5
N2 - The Quaternary Xihuingo-La Paila Volcanic Field comprises basalts and basaltic andesites (0.8–0.5 Ma) that built many scoria cones, shield volcanoes, and contemporaneous (~0.4 Ma) dacitic dome structures, emplaced in the rear-arc area of the Trans-Mexican Volcanic Belt eastern sector. Most basalts and basaltic andesites exhibit LILE/HFS ratios related to subduction processes. Nevertheless, some basaltic cones are alkaline in composition, with trace-element patterns that indicate an enriched mantle source, but Ba and Pb positive anomalies are also present. Although dacitic rocks also display typical trace-element patterns for subduction settings, a simple magmatic liquid line of descent cannot relate the basalts to dacites. The Sr and Nd isotopic values (87Sr/86Sr = 0.70399 to 0.70522 and εNd = +0.25 to +4.80) for felsic and mafic rocks suggest a small interaction of magmas with continental crust components, and the Pb isotopic ratios (206Pb/204Pb = 18.68–18.78; 207Pb/204Pb = 15.58–15.63 and 208Pb/204Pb = 38.44–38.62) show that all volcanic products form a mixing line between a mantle-like component and a radiogenic component like the Palaeozoic Acatlán complex. A slab rollback process probably produced the magmatic migration of the volcanic front to the Middle American trench during the Late Miocene–Quaternary, which favoured the ascent of the asthenosphere to the mantle wedge. Melting of this heterogeneous mantle then produced mafic magmas that intruded the lower continental crust, and dacitic products could be formed by the partial melting of these mafic intrusions emplaced by frequent injections at the base of the continental crust.
AB - The Quaternary Xihuingo-La Paila Volcanic Field comprises basalts and basaltic andesites (0.8–0.5 Ma) that built many scoria cones, shield volcanoes, and contemporaneous (~0.4 Ma) dacitic dome structures, emplaced in the rear-arc area of the Trans-Mexican Volcanic Belt eastern sector. Most basalts and basaltic andesites exhibit LILE/HFS ratios related to subduction processes. Nevertheless, some basaltic cones are alkaline in composition, with trace-element patterns that indicate an enriched mantle source, but Ba and Pb positive anomalies are also present. Although dacitic rocks also display typical trace-element patterns for subduction settings, a simple magmatic liquid line of descent cannot relate the basalts to dacites. The Sr and Nd isotopic values (87Sr/86Sr = 0.70399 to 0.70522 and εNd = +0.25 to +4.80) for felsic and mafic rocks suggest a small interaction of magmas with continental crust components, and the Pb isotopic ratios (206Pb/204Pb = 18.68–18.78; 207Pb/204Pb = 15.58–15.63 and 208Pb/204Pb = 38.44–38.62) show that all volcanic products form a mixing line between a mantle-like component and a radiogenic component like the Palaeozoic Acatlán complex. A slab rollback process probably produced the magmatic migration of the volcanic front to the Middle American trench during the Late Miocene–Quaternary, which favoured the ascent of the asthenosphere to the mantle wedge. Melting of this heterogeneous mantle then produced mafic magmas that intruded the lower continental crust, and dacitic products could be formed by the partial melting of these mafic intrusions emplaced by frequent injections at the base of the continental crust.
KW - bimodal volcanism
KW - geochemistry
KW - isotopes
KW - lower crustal melting
KW - subduction
UR - http://www.scopus.com/inward/record.url?scp=85122867471&partnerID=8YFLogxK
U2 - 10.1002/gj.4390
DO - 10.1002/gj.4390
M3 - Artículo
AN - SCOPUS:85122867471
SN - 0072-1050
VL - 57
SP - 1957
EP - 1977
JO - Geological Journal
JF - Geological Journal
IS - 5
ER -