Geochemistry of metabasites of the Austridic crystalline basement from Monte Pin (Val di Non) central-eastern Alps

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Authors:Bondi, Mirella; Morten, Lauro
Author Affiliations:Primary:
Universita di Bologna, Dipartimento di Scienze della Terra e Geologico-Ambientali, Bologna, Italy
Volume Title:Mineralogica et Petrographica Acta
Source:Mineralogica et Petrographica Acta, Vol.43, p.75-86. Publisher: Istituto di Mineralogia e Petrografia dell'Universita di Bologna, Bologna, Italy. ISSN: 0540-1437
Publication Date:2000
Note:In English with Italian summary. 19 refs.; illus., incl. 1 table
Summary:The metabasites outcropping as intercalations, and concordant and variably boudinated bodies within the biotite-and muscovite-bearing micaschists and paragneisses from the Mt.Pin area (Tonale series, Upper Austroalpine; Non Valley, Trento) have basaltic composition with tholeiitic affinity. A significant chemical difference exists between the inner and outer parts of the same body. The margins are enriched in alkalis, Rb, Ba, Sr and REE, and depleted in MgO, CaO, Ni, Co, V and Cr relative to the inner parts. These differences are believed the result of chemical exchange between the mafic melts and the host metapelites since magmatic differentiation cannot be excluded. The inner parts of metabasites better approach melt compositions (protoliths). On the other hand, chemical signature and mineralogical assemblages indicate that some metabasites derived from cumulitic products. Discrimination diagrams suggest MORB and/or BAB (Back Arc Basin Basalts) geochemical signature for the protoliths. REE contents and patterns show that some protolithic metabasites match those of N-MORB and BAB, while others better approach E- and T-MORB.
Sections:Geochemistry
Subsections:Metamorphic rocks
Subjects:Alkalic composition; Basalts; Basement; Chemical composition; Chemical ratios; Enrichment; Geochemistry; ICP mass spectra; Igneous rocks; Island arcs; Mafic composition; Mass spectra; Melts; Metabasite; Metaigneous rocks; Metals; Metamorphic rocks; Mid-ocean ridge basalts; Mineral composition; Petrography; Protoliths; Rare earths; Silicate melts; Spectra; Trace elements; Volcanic rocks; Alps; Austroalpine Zone; Eastern Alps; Europe; Italy; Southern Europe; Trentino-Alto Adige Italy; Trento Italy; Mount Pin; Non Valley; Tonale Series
Coordinates:N454000 N470800 E0123000 E0102500
Abstract Numbers:05M/4327
Record ID:2006051223
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute.
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