89 research outputs found

    Geology of the San Donato - Costa Thrust Zone, Belluno Thrust System, eastern Southern Alps, northern Italy

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    We present a 1:7500 scale geological map of part of the footwall of the south verging Belluno Thrust of the seismically active eastern Southern Alps of northern Italy. We report a previously unknown thrust zone, the “San Donato-Costa Thrust Zone”, that cuts across the local MesoCenozoic stratigraphic succession. 1:2500 and 1:5000 geological mapping, in combination with the revision and improvement of the local lithostratigraphy and detailed structural analysis, provided new insights into the thrust geometry and the setting of the greater area it deforms. We show that the recorded deformation style (e.g. folding vs. faulting) exhibits notable variations within the affected Meso-Cenozoic stratigraphic succession, with shortening accommodated by fold trains and several subparallel thrust splays with variable amounts of stratigraphic offset cumulated during repeated faulting. Our results contribute to a better definition of folding and faulting within the Mesozoic carbonate multilayer system of the eastern Southern Alps

    Geomorphic signal of active faulting at the northern edge of Lut Block. Insights on the kinematic scenario of Central Iran

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    Recent works documented Neogene to Quaternary dextral strike-slip tectonics along the Kuh-e-Sarhangi and Kuh-e-Faghan intraplate strike-slip faults at the northern edge of the Lut Block of Central Iran, previously thought to be dominated by sinistral strike-slip deformation. This work focuses on the evidence of Quaternary activity of one of these fault systems, in order to provide new spatio-temporal constraints on their role in the active regional kinematic scenario. Through geomorphological and structural investigation, integrated with Optically Stimulated Luminescence (OSL) dating of three generations of alluvial fans and fluvial terraces (at ~53, ~25 and ~6 ka), this study documents (i) the topographic inheritance of the long-term (Myr) punctuated history of fault nucleation, propagation, and exhumation along the northern edge of Lut Block; (ii) the tectonic control on drainage network evolution, pediment formation, fluvial terraces, and alluvial-fan architecture; (iii) the minimum Holocene age of Quaternary dextral strike-slip faulting; and (iv) the evidence of Late Quaternary fault-related uplift localized along the different fault strands. The documented spatial and temporal constraints on the active dextral strike-slip tectonics at the northern edge of Lut Block provided new insights on the kinematic model for active faulting in Central Iran, which has been reinterpreted in an escape tectonic scenario

    Spatio-temporal evolution of intraplate strike-slip faulting: the Neogene-Quaternary Kuh-e-Faghan Fault, Central Iran

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    Central Iran provides an ideal region to study the long-term morphotectonic response to the nucleation and propagation of intraplate faulting. In this study, a multidisciplinary approach that integrates structural and stratigraphic field investigations with apatite (U+Th)/He (AHe) thermochronometry is used to reconstruct the spatio-temporal evolution of the Kuh-e-Faghan Fault (KFF) in northeastern Central Iran. The KFF is a narrow, ca. 80 km long, deformation zone that consists of three main broadly left stepping, E-W trending, dextral fault strands that cut through the Mesozoic-Paleozoic substratum and the Neogene-Quaternary sedimentary cover. The AHe thermochronometry results indicate that the intra-fault blocks along the KFF experienced two major episodes of fault-related exhumation at ~18 Ma and ~4 Ma. The ~18 Ma faulting/exhumation episode is chiefly recorded by the structure and depositional architecture of the Neogene deposits along the KFF. A source-to-sink scenario can be reconstructed for this time frame, where topographic growth caused the synchronous erosion/exhumation of the pre-Neogene units and deposition of the eroded material in the surrounding fault-bounded continental depocenters. Successively, the KFF gradually entered a period of relative tectonic quiescence and, probably, of regional subsidence during which a thick pile of fine-grained onlapping sediments were deposited. This may have caused resetting of the He ages of apatite in the pre-Neogene and the basal Neogene successions. The ~4 Ma faulting episode caused the final exhumation of the fault system, resulting in the current fault zone and topography. The two fault-related exhumation episodes fit with the regional early Miocene collision-enhanced uplift/exhumation, and the late Miocene–early Pliocene widespread tectonic reorganization of the Iranian plateau. The reconstructed long term, spatially and temporally punctuated fault system evolution in intraplate Central Iran during Neogene-Quaternary times may reflect states of far-field stress changes at the collisional boundaries

    Characterization of a Multiresistance Plasmid Carrying the optrA and cfr Resistance Genes From an Enterococcus faecium Clinical Isolate

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    open13noEnterococcus faecium E35048, a bloodstream isolate from Italy, was the first strain where the oxazolidinone resistance gene optrA was detected outside China. The strain was also positive for the oxazolidinone resistance gene cfr. WGS analysis revealed that the two genes were linked (23.1 kb apart), being co-carried by a 41,816-bp plasmid that was named pE35048-oc. This plasmid also carried the macrolide resistance gene erm(B) and a backbone related to that of the well-known Enterococcus faecalis plasmid pRE25 (identity 96%, coverage 65%). The optrA gene context was original, optrA being part of a composite transposon, named Tn6628, which was integrated into the gene encoding for the ζ toxin protein (orf19 of pRE25). The cfr gene was flanked by two ISEnfa5 insertion sequences and the element was inserted into an lnu(E) gene. Both optrA and cfr contexts were excisable. pE35048-oc could not be transferred to enterococcal recipients by conjugation or transformation. A plasmid-cured derivative of E. faecium E35048 was obtained following growth at 42°C, and the complete loss of pE35048-oc was confirmed by WGS. pE35048-oc exhibited some similarity but also notable differences from pEF12-0805, a recently described enterococcal plasmid from human E. faecium also co-carrying optrA and cfr; conversely it was completely unrelated to other optrA- and cfr-carrying plasmids from Staphylococcus sciuri. The optrA-cfr linkage is a matter of concern since it could herald the possibility of a co-spread of the two genes, both involved in resistance to last resort agents such as the oxazolidinones.openMorroni, Gianluca; Brenciani, Andrea; Antonelli, Alberto; Maria D’Andrea, Marco; Di Pilato, Vincenzo; Fioriti, Simona; Mingoia, Marina; Vignaroli, Carla; Cirioni, Oscar; Biavasco, Francesca; Varaldo, Pietro E.; Rossolini, Gian Maria; Giovanetti, EleonoraMorroni, Gianluca; Brenciani, Andrea; Antonelli, Alberto; Maria D’Andrea, Marco; Di Pilato, Vincenzo; Fioriti, Simona; Mingoia, Marina; Vignaroli, Carla; Cirioni, Oscar; Biavasco, Francesca; Varaldo, Pietro E.; Rossolini, Gian Maria; Giovanetti, Eleonor

    Multi-scale geological evaluation for quarrying activities in ophiolitic rocks: Implications for asbestos-related legislation

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    This study illustrates the importance of undertaking a multi-scale geological approach when assessing ophiolites which may contain harmful asbestos. A case history from an active quarry in the Carinthia region of Austria is presented. The data obtained indicated four main zones within the heterogeneous rock mass. The study identified those horizons which could be used for commercial purposes, notably railway ballast and road sub-base. Extensive testing was undertaken which confirmed that asbestiform amphiboles were not present in the quarry. Attention is drawn to the ambiguities in current legislation regarding the presence of asbestos. \ua9 2013 Springer-Verlag Berlin Heidelberg

    SCHISTS AND PIGMENTS FROM ANCIENT SWAT (KHYBER PUKHTUNKHWA, PAKISTAN)

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    Since the earliest agricultural communities settled in the greater Indus basin in the 7th millennium BC, rocks and minerals have had an important role in the local processes of social evolution in order to signal the superior status of elites, as Italian excavations and surveys demonstrated in numerous projects (IsMEO-IsIAO and National Museum of Oriental Art in Rome, MNAO). This paper presents results from minero-petrographic analysis carried out from sculptures exposed in MNAO, with the aim of better understanding their context and provenance. The petro-textural characters have implications for both the conservation of the sculptures and reconstruction of the provenance history of the raw materials from the Swat Valley. A set of brightly coloured particles made of different raw materials (pigments and gold leaf) was also analysed. These precious materials were probably placed in the reliquary alongside a few cremated bones in the frame of a highly symbolic, ritual setting

    Studio geologico-strutturale per l'ottimizzazione della coltivazione di rocce ofiolitiche: il caso della cava "Tana dei Banditi" in localit\ue0 Carpenara (Genova)

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    Exposures of ophiolitic rocks define extractive sites with geological complexities that may influence the quarrying activities. This study concerns the "Tana dei Banditi" quarry located in the Carpenara village (Genoa), managed by the Frantoio del Tigullio Company. Using a multidisciplinary approach that integrated geological-structural and minero-petrographic analyses, we assessed: (I) the geological-structural setting of the quarry, (II) the geological-structural relationships between the extracted lithotype (Capenara metagabbro) and the surrounding units, (III) the petrographic characteristics, (IV) the geometry, distribution, and kinematics of the main deformation structures, and (V) the relationships between deformation structures and secondary mineralization. Our results can: (I) improve the quarry activities through the individuation of specific sectors in the deposit, and (II) provide a firstorder methodology for evaluating critical factors related to quarrying in ophiolitic rocks

    The assessment of particulate matter emitted from stone-crushing industry by correlating rock textures with particles generated after comminution and dispersed in air environment

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    The generation and emission of particulate matter from abrasion industry are subjects of the pollution monitoring by multidisciplinary study involving earth sciences and engineering disciplines. This work investigates the correlation between textural properties of in situ rock with class size distribution and morphology of particles generated after rock comminution and particles emitted in the air. A special comminution-dust sampling architecture was realised. The combined use of scanning electron microscopy and particle size analyser was considered in performing digital image analysis on both crushed products and airborne particles collected onto membrane filters. The results show that the size and morphology of crushed particles are linked to the petrographic rock properties. In particular, particles with fibrous morphology are prominent in rocks showing foliated textures where elongated minerals occurred, with implication for asbestos-bearing rocks. For what concerns the airborne particles, the results show that their aerodynamic diameters are independent of the crusher operating conditions. External parameters probably intervene in the distribution of the airborne particles emission, including the dynamic air fluxes, or environmental conditions. By applying mathematical models, the morphology and size range of airborne particles following the comminution processes can be predicted, and results has implication for pollutants contamination due to particulate matters emitted by crush stone industry. © 2012 Springer-Verlag Berlin Heidelberg
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