The Scaglia Toscana Formation of the Monti del Chianti: new lithostratigraphic and biostratigraphic data

The Scaglia Toscana Formation (Scisti Policromi Auctt.) is one of the most investigated formations of the Tuscan Nappe. The formation is widely exposed in the Chianti Mounts and despite the number of studies in this area, some aspects remain poorly known and debated.In this paper new litho- and bio-stratigraphic data from eight key-sections distributed over the entire area are provided and discussed in order to clarify the stratigraphic relationships among different lithostratigraphic members, as well as the depositional ages of each member. The formation was deposited in the Cretaceous-Oligo-cene time interval and it can be subdivided into five lithostratigraphic members: i) the “Argilliti di Brolio” (wine-red shales with sporadic siliceous calcilutites and rare interbedded cherts); ii) the “Marne del Sugame” (red and pink marls, calcareous marls and marly limestones with interbedded calcarenitic beds and ruditic lens-shaped bodies including calcareous-siliceous clasts); iii) the “Argilliti di Cintoia” (grey-green to black shales, locally with manganese-rich siliceous calcilutites and cherts); iv) the “Calcareniti di Montegrossi” (thin beds of calcilutites and calcarenites with varicoloured shaly-marly interbeds); and v) the “Argilliti e Calcareniti di Dudda” (alternating thin beds of calcilutites and calcarenites with varicoloured shaly-marly interbeds). These members were deposited in a marine environment and have been interpreted as deposited in a turbiditic system, in which shaly and calcareous turbiditic members have been attributed to a basin plain below the CCD, whereas the marls and marly limestones of the Marne del Sugame Member were deposited in a slope/ramp environment above or close to the CCD. Furthermore, the combination of these new data with structural informations coming from the literature allowed a better paleogeographic reconstruction of the paleobasin. In order to better explain these data, the paper is accompanied by two geological maps realized in the past but never distributed. The two geological maps, at the scale of 1:25,000, cover the whole area from the Cintoia (south of Florence) to the San Gusmè (north of Siena) villages

A combined crystallographic and computational study on dexketoprofen trometamol dihydrate salt

Dexketoprofen trometamol is the tromethamine salt of dexketoprofen [(2S)-2-(3-benzoylphenyl)propanoic acid-2-amino-2-(hydroxymethyl)propane-1,3-diol], a nonsteroidal anti-inflammatory drug (NSAID) used for the treatment of moderate- to strong-intensity acute pain. The crystal structure of the hitherto sole known hydrate phase of dexketoprofen trometamol (DK-T_2H2O), as determined by single-crystal X-ray diffraction, is presented. The water molecules are arranged in dimers included in isolated sites and sandwiched between piles of trometamol cations. The molecular and crystal structures of DK-T_2H2O are analyzed and compared to those of the parent anhydrous crystal form DK-T_A. In both the crystal structures, all the potential H-bond donors and acceptor of the dexketoprofen and trometamol ions are engaged, and both the species crystallize in the P21 space group. However, during the DK-T_A➔DK-T_2H2O hydration process, the unique symmetry axis is not conserved, i.e., the ions are arranged in a different way with respect to the screw axis, even if the two crystal structures maintain structural blocks of DK anions and T cations. Quantum mechanical solid-state calculations provide some hints for the possible intermediate structure during the crystalline–crystalline hydration/dehydration process

Fossil mollusk association from Isabela Island (Galápagos, Ecuador)

In this paper a fossiliferous assemblage coming from Puerto Villamil (Isabela, Galápagos) is examined. The sandy sediments chiefly contain a molluscan association besides arthropod pincers, spicules of siliceous sponges, sea urchin spines, barnacle plates, rare foraminifers and abraded fragments of corals and briozoa. The mollusk assemblage represents a subtidal community associated with coral reefs and is dominated by Panamic forms. The modern aspect of this fauna and the radiometric ages till now proposed suggest a Pleistocene age for the Villamil deposits, although the presence of the extinct species Pegophysema spherica, for the first time reported from Isabela, might indicate a Pliocene age

Paleontological and sedimentological observations on the Canoa Formation

A succession of 150 m thick sediments, belonging to the Canoa Formation, was studied. Some specifications on past contradictory descriptions of the formation are provided. These sediments consist of a cycle of the first order and outcrop along the coast, south of Manta (Ecuador), between Punta Canoa and Quebrada El Mangle and have been attributed to a Late Pliocene age (Globigerinoides fistulosus Zone). The fossil assemblages are very rich and well differentiated: foraminifers, molluscs and otoliths (the latter being observed for the first time in this formation). On the basis of lithology and of sedimentologic and paleontologic characteristics, offshore/shoreface environments with foreshore episodes were recognized and a hypothesis for a possible geological evolution of the area was suggested