Occurrence of phlogopite in the Finero Mafic layered complex

Autor(es)

Giovanardi, Tommaso ^{[1, 2, 3]} ; Mazzucchelli, Maurizio ^{[2, 4]} ; Zanetti, Alberto ^[4] ; Langone, Antonio ^[4] ; Tiepolo, Massimo ^[4] ; Cipriani, Anna ^{[2, 5]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Geociencias, BR-05508900 Sao Paulo - Brazil

^[2] Univ Modena & Reggio Emilia, Dipartimento Sci Chim & Geol, I-41121 Modena - Italy

^[3] Univ Pavia, Dipartimento Sci Terra & Ambiente, I-27100 Pavia - Italy

^[4] UOS Pavia, CNR, Ist Geosci & Georisorse, I-27100 Pavia - Italy

^[5] Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 - USA

• Tipo de documento: Artigo Científico
• Fonte: CENTRAL EUROPEAN JOURNAL OF GEOSCIENCES; v. 6, n. 4, p. 588-613, DEC 2014.
• Citações Web of Science: 7

Resumo

Phlogopite-bearing lithologies are the main constituent of the Phlogopite-Peridotite unit of the Finero sequence and the result of pervasive migration of metasomatizing melts/fluids. Conversely, the presence of phlogopite within the associated Finero Mafic Complex, a mafic-ultramafic pluton intruded into the metamorphic basement of the Adria plate, is mentioned in literature as rare. Recent detailed fieldwork has evidenced the presence of two distinct phlogopite-rich ultramafic lithologies within the Amphibole-Peridotite unit of the Finero Mafic Complex, where phlogopite is always associated with amphibole. Field and petrographic features of these occurrences, as well as major- and trace-element mineral chemistry, are here presented to i) place constraints on the nature of the parent melt from which they have been generated and ii) to address their relationship with the other lithologies of the Finero Complex. We find that these rocks were formed by late melt migrations along shear zones under high-T conditions. The geochemical affinity of these lithologies is different to the tholeiitic-transitional affinity reported in literature for the Finero Mafic Complex. The enrichment in LREE, Th, U and Sr of the associated amphibole possibly suggests that these phlogopite-bearing lithologies are genetically related to the metasomatic events that have affected the Finero mantle massif. (AU)

• Processo FAPESP: 13/19519-6 - Geoquímica e modelação de intrusões básicas no Cana Brava e Niquelândia Complexos máfico-ultramáficos.
• Beneficiário: Tommaso Giovanardi
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado