2026-06-07T15:51:05Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/713082023-07-13T02:31:13Zcom_20.500.14352_14col_20.500.14352_15

The unique Cambro-Ordovician silicic large igneous province of NW Gondwana: Catastrophic melting of a thinned crust Rodríguez, Carmen Castro, Antonio Gómez Frutos, Daniel Gutiérrez Alonso, Gabriel Pereira, Manuel Francisco Fernández, Carlos Cambro–Ordovician silicic magmatism in the Central Iberian Zone of the Iberian Massif (Ollo de Sapo Formation, OSF) constitutes a voluminous and geochemically atypical magmatic event that formed preceding the breakup of the northern margin of Gondwana. To date, and due to uncommon geochemical signatures, such as a high Fe, Mg content compared to anatectic melts and the departing from the calc-alkaline trends, the origin of such magmatic event is not fully understood. Herein, we report a data-analysis of geochemistry linking magmas and source compositions. The analysis of the combined data from multiple studies ascribes the geochemistry of the OSF rocks to a combination of extensive melting of Ediacaran metasiliciclastic rocks and a Ca-rich component. It is hypothesized that fluids released by crystallization of mafic magmas contributed to partial melting of a thick metasedimentary pile represented by Ediacaran siliciclastic rocks. Such melting event gave rise to a mobile nebulite or migma, which was able to extrude and form the super-eruption or “flare-up” that characterizes Cambro-Ordovician silicic magmatism at the Gondwana margin. Fast, catastrophic crustal melting with large-scale restite entrainment, triggered by the influx of mafic magma-derived fluids, are considered the main cause of the unique features of this Cambro-Ordovician atypical silicic large igneous province of Gondwana. 2023-06-22T10:40:32Z 2023-06-22T10:40:32Z 2023-06-22T10:40:32Z 2022-02-03 journal article https://hdl.handle.net/20.500.14352/71308 1342-937X 10.1016/j.gr.2022.01.011 eng IBERCRUST (PGC2018-096534-B-I00) UIDB/04683/2020 https://creativecommons.org/licenses/by-nc-nd/3.0/es/ open access Atribución-NoComercial-SinDerivadas 3.0 España Elsevier