Search results for " Hyblean Plateau."
showing 6 items of 6 documents
A TWO-COMPONENT MANTLE EXTENDING FROM MT. ETNA TO HYBLEAN PLATEAU (EASTERN SICILY) AS INFERRED BY AN INTEGRATED APPROACH WITH NOBLE GASES, TRACE ELEM…
2012
A two-component mantle extending from Hyblean Plateau to Mt Etna (Eastern Sicily) as inferred by an integrated approach with noble gases, trace eleme…
2012
We carried out a geochemical investigation of the mantle beneath Hyblean and Etnean area through ultramafic xenoliths (peridotites and pyroxenites) retained in Miocenic age Hyblean volcanics and primitive Etnean lavas and tephra, respectively. Major and trace elements and Sr-Nd isotopes (whole rock and /or minerals) were analysed together with noble gases entrapped in fluid inclusions hosted in olivines and pyroxenes phenocrysts. The geochemical results from Hyblean xenoliths study highlighted the presence of two distinct compositional groups: the peridotites, featured by a more enriched geochemical fingerprint (3He/4He ∼7 Ra, 143Nd/144Nd ∼0.5129 and Zr/Nb ∼ 4) whereas the pyroxenites, char…
A two-component mantle source feeding Mt. Etna magmatism; insights from the geochemistry of primitive magmas.
2014
The major elements, trace elements and Sr and Nd isotopes of selected Etnean primitive rocks (b15 ky BP) were studied in order to characterize their mantle source. The noble-gas geochemistry of fluid inclusions in minerals fromthe same lavaswas also investigated. Themajor element compositions ofwhole rocks and minerals showed that these products are among the most primitive atMt. Etna, comprising 6.3–17.5 wt.% MgO. The variable LREE (Light Rare Earth Elements) enrichment relative to MORB (Mid-Ocean Ridge Basalt) (Lan/Ybn = 11–26), togetherwith the patterns of certain trace-element ratios (i.e., Ce/Yb versus Zr/Nb and Th/Y versus La/Yb), can be attributed to varying degrees of melting of a c…
CHLORITE/SMECTITE - ALKALI FELDSPAR METASOMATIC XENOLITHS FROM HYBLEAN MIOCENIC DIATREMES (SICILY, ITALY): EVIDENCE FOR EARLY INTERACTION BETWEEN HYD…
2006
Upper-Miocene tuff-breccia pipes from the Hyblean area (south-eastern Sicily) bear a number of ultramafic and mafic xenoliths (spinel-peridotites, pyroxenites, gabbroic rocks) whose study has led to conclude that the Meso-Caenozoic carbonatic and volcanic succession stands upon a fossil oceanic core-complex, probably connected with the adjacent Ionian crust. Evidence for hydrothermal metasomatism is common in the Hyblean ultramafic and mafic xenoliths. In some cases, extreme metasomatic transformation and shearing have deleted original mineralogy and textures yielding unusual rocks, hereafter called “metasomatites”. These rocks generally exhibit cataclastic texture, their hydrothermal miner…
Preliminary results of fault-related permeability structures associated to the Scicli-Ragusa fault segments, Hyblean Plateau, Sicily
2010
Nella zona di Ragusa (Plateau Ibleo, Sicilia sud-orientale) la presenza di bitume all’interno di rocce carbonatiche di età oligo-miocenica, caratterizzate da una porosità primaria oggi compresa tra 0 e 10% (Formazione Ragusa, permette di osservare il ruolo esercitato da faglie e fratture nella circolazione degli idrocarburi. Con l’obiettivo quindi di effettuare studi mirati alla caratterizzazione petrofisica delle diverse tipologie di faglie e fratture affioranti, è stato condotto uno studio di terreno preliminare, che ha permesso la definizione dell’assetto geologico-strutturale della porzione occidentale del Plateau Ibleo, lungo il sistema di faglie denominato Scicli-Ragusa. Inoltre, sull…
Preliminary results of a multi-scale structural analisys in an analogue carbonate reservoir (Hyblean Plateau, Sicily, Italy)
2010
With the aim of studying the multi-scale fault architecture and permeability in hydrocarbon-rich porous carbonate rocks, we are currently involved in a project focused on the structural analysis of fractured and faulted platform-to-ramp carbonates cropping out in the Hyblean Plateau (Sicily, Italy). The Hyblean Plateau is part of the Maghrebian foreland and forms the northern portion of the African plate. The plateau is a NE-oriented structural high crosscut by a large-scale N10°-20°E oriented strike-slip fault system, named Scicli-Ragusa, which was affected by right-lateral kinematics during the Upper Miocene-Lower Pliocene. Some authors documented a recent activity of the Scicli-Ragusa fa…