Peer-reviewed articles 17,970 +


Title: PETROLOGY AND GEOCHEMISTRY OF THE FELSIC HYPABYSSAL MAGMATISM IN NORTHERN PORTUGAL (CENTRAL IBERIAN ZONE)
PETROLOGY AND GEOCHEMISTRY OF THE FELSIC HYPABYSSAL MAGMATISM IN NORTHERN PORTUGAL (CENTRAL IBERIAN ZONE)

PlumX Article Metrics by Elsevier
Antonio Oliveira; Helena Martins; Helena Sant’Ovaia
10.5593/sgem2023/1.1/s01.13
10.5593/sgem2023/1.1
1314-2704
978-619-7603-56-9
English
23
1
•    Prof. DSc. Oleksandr Trofymchuk, UKRAINE 
•    Prof. Dr. hab. oec. Baiba Rivza, LATVIA
Geology
In the Central Iberian Zone, multiple subvolcanic intrusions were emplaced during the final stages of the Variscan orogeny. The felsic component of this magmatic episode is mainly represented by dykes and masses of granite porphyries and microgranites, which can be commonly found in northern Portugal. Overall, these rocks are more evolved and enriched in rare incompatible metal elements (such as Li, Be, Rb, Cs, Nb, Ta, Sn, and W) when compared to the regional Variscan granites. The data acquired from the lithogeochemical study reported in this paper suggest that most porphyries/microgranites presumably resulted from anatexis of metapelitic protoliths, with some metagreywacke/orthogneiss contribution. The existing compositional diversity is essentially explained by important differences regarding partial melting conditions, source heterogeneity, and the crystal fractionation phenomenon. The aforementioned enrichments are most likely associated with the composition of the sources, muscovite and biotite-dehydration-melting reactions, and fractionation of feldspar, biotite, and Fe-Ti oxide-dominated mineral assemblages.
[1] Neves, L.J.P.F., Godinho, M.M., Pereira, A.J.S.C., O filao leucogranitico de Borralhal-Salgueiral (Viseu, Portugal Central): uma rocha HHP rica em fosforo e geoquimicamente especializada, Com. Inst. Geol. Min., 86, Portugal, 1999, pp. 15-24;
[2] Oliveira, A., Martins, H.C.B., Sant’Ovaia, H., Petrogenetic constraints on the felsic vein magmatism in northern Portugal based on petrological and geochemical data, Comptes Rendus Geoscience – Sciences de la Planete, 353 (1), 2021, pp. 377-398, https://doi.org/10.5802/crgeos.100;
[3] Oliveira, A., Martins, H.C.B., Sant’Ovaia, H., Permo-Carboniferous hypabyssal magmatism in northern Portugal: the case of the Lamas de Olo microgranite and lamprophyre dykes, Journal of Iberian Geology, 48, 2022, pp. 1-28, https://doi.org/10.1007/s41513-021-00179-8;
[4] Pearce, J.A., Harris, N.B.W., Tindle, A.G., Trace Element Discrimination Diagrams for the Tectonic Interpretation of Granitic Rocks, Journal of Petrology, 25 (4), 1984, pp. 956-983, https://doi.org/10.1093/petrology/25.4.956;
[5] Martins, H.C.B., Sant’Ovaia, H., Noronha, F., Genesis and emplacement of felsic Variscan plutons within a deep crustal lineation, the Penacova-Regua-Verin fault: An integrated geophysics and geochemical study (NW Iberian Peninsula), Lithos, 111 (3- 4), 2009, pp. 142-155, https://doi.org/10.1016/j.lithos.2008.10.018;
[6] Ferreira, J.A., Mata, J., Bento dos Santos, T., Pereira, I., The role of melting on the geochemical evolution and isotopic variability of an anatectic complex in the Iberian Variscides, Lithos, 378, 2020, 105769, https://doi.org/10.1016/j.lithos.2020.105769;
[7] Gomes, M.E.P., Neves, L.J.P.F., Coelho, F., Carvalho, A., Sousa, M., Pereira, A.J.S.C., Geochemistry of granites and metasediments of the urban area of Vila Real (northern Portugal) and correlative radon risk, Environmental Earth Sciences, 64, 2011, pp. 497-502, https://doi.org/10.1007/s12665-010-0873-z;
[8] Boynton, W.V., Geochemistry of the rare earth elements: meteorite studies, In: Henderson, P. (Eds.), Rare Earth Element Geochemistry, Elsevier, Amsterdam, 1984, pp. 63-114, https://doi.org/10.1016/B978-0-444-42148-7.50008-3;
[9] McDonough, W.F., & Sun, S.S., The Composition of the Earth, Chemical Geology, 120 (3-4), 1995, pp. 223-253, https://doi.org/10.1016/0009-2541(94)00140-4;
[10] Patino Douce, A.E., What do experiments tell us about the relative contributions of crust and mantle to the origin of granitic magmas?, Geological Society, London, Special Publications, 168, 1999, pp. 55-75, https://doi.org/10.1144/GSL.SP.1999.168.01.05;
[11] Jung, S., Masberg, P., Mihm, D., Hoernes, S., Partial melting of diverse crustal sources – constraints from Sr–Nd–O isotope compositions of quartz dioritegranodiorite- leucogranite associations (Kaoko Belt, Namibia), Lithos, 111 (3-4), 2009, pp. 236-251, https://doi.org/10.1016/j.lithos.2008.10.010;
[12] Sylvester, P.J., Post-collisional strongly peraluminous granites, Lithos, 45 (1-4), 1998, pp. 29-44, https://doi.org/10.1016/S0024-4937(98)00024-3;
[13] Inger, S., & Harris, N., Geochemical Constraints on Leucogranite Magmatism in the Langtang Valley, Nepal Himalaya, Journal of Petrology, 34 (2), 1993, pp. 345-368, https://doi.org/10.1093/petrology/34.2.345.
This work is supported by national funding awarded by FCT – Foundation for Science and Technology, I.P., projects UIDB/04683/2020 and UIDP/04683/2020. The main author is also financially supported by FCT through an individual Ph.D. grant (reference SFRH/BD/138818/2018).
conference
https://doi.org/10.5593/sgem2023/1.1/s01.13
Download PDF
Proceedings of 23rd International Multidisciplinary Scientific GeoConference SGEM 2023
23rd International Multidisciplinary Scientific GeoConference SGEM 2023, 03 - 09 July, 2023
Proceedings Paper
STEF92 Technology
International Multidisciplinary Scientific GeoConference-SGEM
SWS Scholarly Society; Acad Sci Czech Republ; Latvian Acad Sci; Polish Acad Sci; Russian Acad Sci; Serbian Acad Sci and Arts; Natl Acad Sci Ukraine; Natl Acad Sci Armenia; Sci Council Japan; European Acad Sci, Arts and Letters; Acad Fine Arts Zagreb Croatia; Croatian Acad Sci and Arts; Acad Sci Moldova; Montenegrin Acad Sci and Arts; Georgian Acad Sci; Acad Fine Arts and Design Bratislava; Russian Acad Arts; Turkish Acad Sci.
101-108
03 - 09 July, 2023
website
9002
Granite Porphyries, Microgranites, Dykes, Northern Portugal, Variscan Orogeny