New 40Ar/39Ar ages and major and trace element geochemistry of the middle-late Miocene Cabo de Gata volcanic complex, southeast Spain, indicate that the volcanic activity of the Cabo de Gata volcanic zone developed over a short period through several pulses of geochemically and isotopically different parental magmas. The oldest volcanic rocks exposed in the Cabo de Gata volcanic zone are the shoshonite and high-K calc-alkaline rocks of Bujo group, which crystallised from a parental magma transitional from calc-alkaline to alkaline potassic generated through large degrees of partial melting, and then affected by a minor contribution from metasomatised veins and a larger one from the surrounding mantle wedge, in comparison to ultrapotassic melts. Subsequent partial melting of the mantle source produced typical calc-alkaline parental magmas belonging to the Rodalquilar and Agua Amarga groups. Sr-Nd-Pb isotope and incompatible trace element distributions of Cabo de Gata rocks are in agreement with a mantle-wedge source affected by a two-fold metasomatism. The data suggested that mild potassic to sub-alkaline subduction-related parental magmas (i.e., high-K calc-alkaline and calc-alkaline) were generated in the Cabo de Gata sector within a mantle wedge metasomatised by a fluid-dominated agent. In contrast, the enrichment in K2O of shoshonitic to ultrapotassic magmas was achieved through recycling of subducted sediments through melts that enriched the mantle wedge in K and related elements. Such a scenario can be easily reconciled with a geodynamic setting at the edge of a destructive plate margin with the subducted slab responsible for the recycling of sediments within the mantle wedge.

Geochronology, Geochemistry and Geodynamics of the Cabo de Gata volcanic zone, Southeastern Spain / Mattei, M.; Riggs, N.R.; Giordano, G.; Guarnieri, L.; Cifelli, F.; Soriano, C.C.; Jicha, B.; Jasim, A.; Marchionni, S.; Franciosi, L.; Tommasini, S.; Porreca, M.; Conticelli, S.. - In: ITALIAN JOURNAL OF GEOSCIENCES. - ISSN 2038-1719. - STAMPA. - 133:(2014), pp. 341-361. [10.3301/IJG.2014.44]

Geochronology, Geochemistry and Geodynamics of the Cabo de Gata volcanic zone, Southeastern Spain

GUARNIERI, LUISA;MARCHIONNI, SARA;TOMMASINI, SIMONE;CONTICELLI, SANDRO
2014

Abstract

New 40Ar/39Ar ages and major and trace element geochemistry of the middle-late Miocene Cabo de Gata volcanic complex, southeast Spain, indicate that the volcanic activity of the Cabo de Gata volcanic zone developed over a short period through several pulses of geochemically and isotopically different parental magmas. The oldest volcanic rocks exposed in the Cabo de Gata volcanic zone are the shoshonite and high-K calc-alkaline rocks of Bujo group, which crystallised from a parental magma transitional from calc-alkaline to alkaline potassic generated through large degrees of partial melting, and then affected by a minor contribution from metasomatised veins and a larger one from the surrounding mantle wedge, in comparison to ultrapotassic melts. Subsequent partial melting of the mantle source produced typical calc-alkaline parental magmas belonging to the Rodalquilar and Agua Amarga groups. Sr-Nd-Pb isotope and incompatible trace element distributions of Cabo de Gata rocks are in agreement with a mantle-wedge source affected by a two-fold metasomatism. The data suggested that mild potassic to sub-alkaline subduction-related parental magmas (i.e., high-K calc-alkaline and calc-alkaline) were generated in the Cabo de Gata sector within a mantle wedge metasomatised by a fluid-dominated agent. In contrast, the enrichment in K2O of shoshonitic to ultrapotassic magmas was achieved through recycling of subducted sediments through melts that enriched the mantle wedge in K and related elements. Such a scenario can be easily reconciled with a geodynamic setting at the edge of a destructive plate margin with the subducted slab responsible for the recycling of sediments within the mantle wedge.
2014
133
341
361
Mattei, M.; Riggs, N.R.; Giordano, G.; Guarnieri, L.; Cifelli, F.; Soriano, C.C.; Jicha, B.; Jasim, A.; Marchionni, S.; Franciosi, L.; Tommasini, S.; Porreca, M.; Conticelli, S.
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Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/913931
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