2026-06-29T08:15:42Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/1337922026-03-05T00:45:38Zcom_20.500.14352_14col_20.500.14352_15

Andean-type granites in a non-Andean post-collisional setting, Central System batholith, Spain Abati Gómez, Jacobo Castro Dorado, Antonio Gómez Frutos, Daniel Gutiérrez Alonso, Gabriel Stockli, Daniel F. 552.32(460) Petrología 2506.13 Petrología Ignea y Metamórfica The youngest granite suite of the Spanish Central System batholith (CSB) is classically interpreted as a post-collisional magmatic suite emplaced during the final stages of the Variscan orogeny. However, we report here for the first time the presence of discrete Andean-type plutons within the dominant post-collisional batholith. These plutons exhibit petrographic and geochemical signatures consistent with calc-alkaline series, including Ca-rich clinopyroxene and trace element trends that align with experimental cotectic arrays typical of active margin magmatism. MELTS modeling and phase-equilibrium constraints indicate that the parental magmas derived from a mantle-crust hybrid zone likely formed through localized recycling of oceanic-like mafic rocks during continental subduction. U-Pb zircon ages (312–306 Ma) confirm their temporal overlap with post-collisional granites. The low abundance of xenocrystic zircons (<5%) implies limited crustal assimilation, supporting a dominantly mantle-derived origin. We propose that back-arc basin closure and the subduction of hyperextended segments of Gondwana’s margin facilitated the transient involvement of oceanic components, generating conditions favorable for Andean-type magmatism within a nominally post-collisional context. This scenario challenges the conventional spatial and temporal dichotomy between Andean-type and post-collisional granite types and highlights the petrogenetic diversity inherent to late-orogenic magmatism. Our findings underscore the need to reassess current classification schemes for Variscan batholiths and advocate for integrated geochemical, petrographic, and geochronological approaches in unraveling complex source-to-pluton pathways. Agencia Estatal de Investigación Depto. de Mineralogía y Petrología Fac. de Ciencias Geológicas TRUE pub 2026-03-04T18:54:55Z 2026-03-04T18:54:55Z 2025-10-23 journal article VoR https://hdl.handle.net/20.500.14352/133792 0016-7606 10.1130/B38612.1 1943-2674 eng IBERCRUST II (PID2021-126347NB-I00 MCRUST (PID2024-155155NB-I00 Morales, J., Gerding, J., Compaña, J. M., Astilleros García-Monge, J. M., Fernández-Díaz, L., & Gómez Barreiro, J. (2026). The growth of CaCO3 polymorphs in the presence of As(v): Stabilization of the vaterite phase. Environmental Science: Processes & Impacts, 28(2), 498-509. https://doi.org/10.1039/D5EM00364D restricted access application/pdf Geological Society of America