isopachs and of its lithofacies in the Tacchi area evidences the presence, and the subsequent gradual burial and flooding, of a morpho-structural high («alto morfostrutturale barbaricino») developed in Central Sardinia, due to the coeval extensional tectonics prevailing during the Lower and Middle Jurassic. The comprehensive analysis of the Genna Selole Fm. We propose two others additional parastratotypes for this formation in the Escalaplano and Perdasdefogu areas, characterized by good continuity and exposure, and so integrating the stratotype described by DIENI et alii (1983). (slumps, synsedimentary faults, neptunian dykes, seismic breccias) suggest active coeval extensional tectonics. In addition, features observed in the Genna Selole Fm. has been subdivided into three lithofacies: A) a conglomeratic lithofacies (Laconi-Gadoni Lithofacies) B) a sandyclayey lithofacies (Nurri-Escalaplano Lithofacies) and a mixed siliciclastic-carbonate lithofacies (Ussassai-Perdasdefogu Lithofacies), this latter constituting the gradual passage to the following Dorgali Dolostones Fm.
Based on new evidence, the Genna Selole Fm. suggests the presence of uplifted areas of erosion and alteration whose location has been controlled by structural, syn-depositional factors, as a possible Variscan paleo-high. (Bathonian-Kimmeridgian) (DIENI et alii, 1983), directly overlies the folded Paleozoic basement. In places the Genna Selole is absent and so the marine Dorgali Dolostones Fm. It was laid down in depositional environments ranging from distal alluvial fan to transitional lagoonal-littoral. (Bajocian-Bathonian) (DIENI et alii, 1983), constituting the base of the Tacchi Jurassic succession, is built of siliciclastic to mixed, siliciclastic-carbonate, deposits. Geological mapping and litho-sedimentological analysis heve provided a detailed framework for the vertical and areal development and evolution of the sedimentary facies, and also allowed an accurate paleogeographical construction. Tacchi area (Eastern Sardinia) have given a more detailed knowledge of the local stratigraphy and sedimentology. New investigations carried on the Jurassic successions of the more Stratigraphy, Facies Analysis, Paleogeography and Regionalįramework of the Jurassic succession of the «Tacchi» area Stratigraphy, Facies Analysis, Paleogeography and Regionalįramework of the Jurassic succession.
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