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The Pozanti-Karsanti ophiolite (PKO), forming one of the late Cretaceous discontinuous oceanic lithosphere remnants in the eastern Tauride belt in southern Turkey, is characterized by mantle tectonites, ultramafic and mafic cumulates, isotropic gabbros, sheeted dikes and volcanics. Well-preserved crustal cumulate rocks are mainly composed of dunite+/-chromite, wehrlite, olivine clinopyroxenite, clinopyroxenite,...
In the Eastern Alps, a heterogeneous pile of Pre-Mesozoic and Mesozoic nappes was emplaced during several distinct orogenic events. Ultramafic rocks are preserved in: (1) Pre-Mesozoic basement units of the Penninic Tauern Window and in Austroalpine basement complexes, and (2) in Mesozoic units within Penninic windows and in overlying Austroalpine segments. Geochemical data (major, trace and rare earth...
The incomplete and dismembered Evros ophiolite is situated in Thrace, NE Greece, and belongs to the Circum-Rhodope Belt (CRB). Its age is considered to be Jurassic-Lower Cretaceous. The geotectonic setting of the ophiolite was a volcanic arc-marginal basin system in the Vardar oceanic realm.In the uppermost level of the ophiolitic sequence, volcanic and pyroclastic rocks of tholeiitic composition...
The Baer-Bassit ophiolite, of inferred Late Cretaceous age, was emplaced from the south Tethys ocean onto the leading edge of the Arabian continental margin in latest Cretaceous (Maastrichtian) time. Dismembered sequences in different thrust sheets can be correlated to produce a complete ophiolite sequence, with a metamorphic sole at the base, overlain, in turn, by upper mantle tectonite, rare cumulates,...
Dismembered ophiolites on the Southern Aegean islands of Crete, Karpathos and Rhodes link the Jurassic ophiolites of the Hellenides (e.g., Pindos, Vourinos) and the Cretaceous ophiolites of the Taurides in southern Turkey (e.g., Antalya). The ophiolites of these islands do not form a continuous belt. There are significant differences in composition and age between the ophiolites of Crete in the west...
Within the western belt of the southern Albanian ophiolites, the Voskopoja ophiolite consists of three subunits: Voskopoja, Morava and Rehove. These are predominantly lherzolites with minor harzburgites and dunites in the mantle section. Above come ultramafic and mafic cumulates including wehrlites, troctolites and olivine gabbros. Gabbronorites are restricted to the Morava subunit. Isotropic clinopyroxene...
Dismembered ophiolites occur in the Dinaride Ophiolite Zone (DOZ) that is related to the open-ocean Tethyan realm, whereas highly dismembered ophiolites occur in the Vardar Zone (VZ) related to a back-arc basin. The ophiolites of DOZ are associated with a Jurassic olistostrome melange (DOZM), the youngest component of which are Tithonian limestone exotics and with the Mesozoic bed-to-bed Radiolarite...
The Eastern Mediterranean region exhibits a fascinating diversity of ophiolites and related oceanic magmatic units of mainly Triassic, Jurassic and Cretaceous age. Comparisons with the settings of modern oceanic lithosphere indicate that the various Eastern Mediterranean ophiolites have different origins and formed in a variety of tectonic settings. Some have argued that the largest ophiolites, of...
Magma mixing structures from three different lava flows (Salina, Vulcano and Lesbos) are studied in order to assess the possible chaotic origin of magma mixing processes. Structures are analysed using a new technique based on image analysis procedures that extract time series that are representative of the relative change in composition through the structures. These time series are then used to reconstruct...
Olivine crystal size distributions (CSDs) have been measured in three suites of spinel- and garnet-bearing harzburgites and lherzolites found as xenoliths in alkaline basalts from Canary Islands, Africa; Victoria Land, Antarctica; and Pali Aike, South America. The xenoliths derive from lithospheric mantle, from depths ranging from 80 to 20 km. Their textures vary from coarse to porphyroclastic and...
Magma mixing structures from the lava flow of Lesbos (Greece) are analyzed in three dimensions using a technique that, starting from the serial sections of rock cubes, allows the reconstruction of the spatial distribution of magmas inside rocks. Two main kinds of coexisting structures are observed: (i) ''active regions'' (AR) in which magmas mix intimately generating wide contact surfaces and (ii)...
Upper Pollara eruption products (13 ka, Salina Island, Italy) include both homogeneous and heterogeneous pumices resulting from mixing/mingling processes between an HK andesite and a high-SiO 2 rhyolite. Representative samples of heterogeneous pumices are collected and analyzed in order to check the correspondence between glass composition and morphological features of the mingling/mixing...
A fractal (power-law) distribution is the only statistical distribution applicable to a scale-invariant process. One of the major problems in petrology is the distribution of trace elements in the Earth's crust. Extreme values of this distribution result in ore deposits. There is accumulating observational evidence that tonnage-grade statistics of ore deposits are often fractal (power-law). Rayleigh...
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