UnissResearch

Logo Universitàegli studi di Sassari
titoli, abstracts, parole chiave >>>
Iron and manganese accumulations in Sardinia: the role of supergenic and hydrothermal processes

Sinisi, Rosa (2011) Iron and manganese accumulations in Sardinia: the role of supergenic and hydrothermal processes. Doctoral Thesis.

[img]
Preview
Full text disponibile come PDF Richiede visualizzatore di PDF come GSview, Xpdf o Adobe Acrobat Reader
9Mb

Abstract

This paper examines the compositional features of some Fe and Mn accumulations of Sardinia in order to reconstruct the palaeoenvironmental conditions of ores formation, to better characterize the processes that lead to Fe and Mn minerals formation and to compare the Fe and Mn geochemical behavior within different depositional environments. The research focused on comparison between: 1) continental Fe oxyhydroxides concentrations, formed under oxic conditions on a palaeosurfaces of the Tacchi area, and the Uppermost Ordovician oolitic ironstones of shallow anoxic marine environment of the Nurra district; 2) marine supergene Mn ores of Logudoro Basin, hosted in a littoral conglomerate laying at the base of the Miocene transgressive calcareous sediments, and continental hydrothermal Mn mineralizations of San Pietro Island and Anglona district where they are the stockwork and veins filling within Miocene volcanic sequences. Chemical analyses (XRF, INAA and ICP-MS), XRD analysis, OM and SEM-EDS observations were performed on each samples. The analyses results suggest that although the Sardinian ores formed in different environments (marine vs continental) and under contrasting climatic (sub-glacial vs tropical) and environmental (supergene vs hydrothermal) conditions, they share similar mineralogical or geochemical features. Therefore, not necessarily dramatic palaeoenvironmental differences find a counterpart in geochemical features of the chemical sediments.

Item Type:Doctoral Thesis
ID Code:5134
Contributors:Mameli, Paola and Mongelli, Giovanni and Oggiano, Giacomo
Publisher:Universita' degli studi di Sassari
Uncontrolled Keywords:Ironstones, Mn ores, geochemistry, palaeoenvironments, Sardinia
Subjects:Area 04 - Scienze della terra > GEO/09 Georisorse minerarie e applicazioni mineralogico- petrografiche per l'ambiente ed i beni culturali
Divisions:001 Università di Sassari > 01 Dipartimenti > Zoologia e genetica evoluzionistica
Cicli, scuole e corsi:Ciclo 23 > Scuole > Scienze della natura e delle sue risorse > Scienza e tecnologia dei minerali e delle rocce di interesse industriale
Deposited On:11 Apr 2011 09:10

I documenti depositati in UnissResearch sono protetti dalle leggi che regolano il diritto d'autore

Repository Staff Only: item control page