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    The Monte Penna thrust (Southern Tuscany, Italy): geometry and kinematic of a collisional structure affecting the Tuscan Nappe during the Northern Apennines orogenic building

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    In this paper we describe the geometry and kinematics of a contractional structure, consisting of a thrust and related minor structures, which doubled the Tuscan Nappe cropping out in the southern side of the Monte Amiata geothermal region (Selvena-Castell’Azzara area), during the building of the Northern Apennines. Such a thrust (hereafter the Monte Penna thrust, MPT) is documented, in this area, for the first time. The integration of fieldwork with mine data from two different cinnabar/stibnite mines helped us to better define the thrust geometrical setting both at the surface and underground. Thrusting took place during the Early Miocene and produced the tectonic repetition of the Tuscan Nappe succession. The thrust gave rise to two tectonic subunits (SU1 and SU2) separated by a contractional shear zone up to 3m thick. Such a shear zone consists of three structural domains characterised by different structures such as folds, a tectonic foliation, reverse faults and Riedel shear fractures. They indicate a top-to-the ESE sense of shear, coherently with the general staking pattern of the Northern Apennines belt at least for the study area and surroundings. The thrust-sheet was deformed by cartographic- to mesoscopic folds, N135° to N220° striking on average, NE- and SE-verging, respectively. The tectonic setting recognised in the study area is coherent with that of the Tuscan Nappe described for the Monte Amiata region and the whole southern Tuscany, resulting characterised by duplex system. Such a duplex system was affected by extensional structures since the Middle Miocene. Presently, the thrusts consist of relic structures preserved within extensional horses. The whole evidence possibly make the Tuscan Nappe duplex system comparable with the structure of the Tuscan Metamorphic «basement», in terms of geometry, stacking pattern and timing, suggesting a probable common structural evolution even if a different structural level

    Tradizione e innovazione nella gestione tecnico-viticola del Sangiovese.

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    L’evoluzione in termini qualitativi e la contemporanea contrazione dei consumi di vino, hanno imposto una sostanziale modificazione della gestione tecnico-colturale dei vigneti. Si è quindi cercato di mettere in atto a diversi livelli, tecnico-pratico e scientifico, un modello di viticoltura compatibile con le caratteristiche ecopedologiche dei siti di coltivazione, in cui fosse necessario il minimo di input esterni per raggiungere i livelli qualitativi massimi possibili in relazione alla vocazione ambientale. Per trattare di tecniche colturali applicate al vigneto si può partire da diversi approcci: di quanto si possono tagliare i costi di produzione, quanto può essere migliorata l’espressione del territorio nel prodotto finale. Per le regioni costrette per situazioni ambientali e per limitazioni di carattere normativo a produrre a livelli bassi per ettaro, non può che esistere la seconda soluzion

    Transtensional shear zones controlling volcanic eruptions: the Middle Pleistocene Mt Amiata volcano (inner Northern Apenines, Italy)

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    The Mt Amiata volcano is characterized by the SW-NE alignment of the eruption centres, as well as other Italian Pleistocene volcanoes. We carried out a structural and kinematic analysis in a broad stripe comprehending the eruption centres and the substratum, towards NE and SW. The results point out that a transtensional left-lateral brittle shear zone affects the pre-Neogene substratum, the Middle Pleistocene volcanic rocks and the Late Pleistocene travertines. This transtensional structure is active since the Early Pliocene. It controlled the location of the eruption centres through pull-apart structures, thus providing the deep structural channels for the uprising of magma to the surface. The Mt Amiata volcano represents a key study area to investigate the Pleistocene to Present relationships between tectonics and magmatism in the Tyrrhenian area. © 2010 Blackwell Publishing Ltd
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