Weathering Products of a Dismantled Variscan Basement. Minero-Chemical Proxies to Insight on Cretaceous Palaeogeography and Late Neogene Palaeoclimate of Sardinia (Italy)
This study compares, for the first time, the mineralogy and geochemistry of two residual-clay deposits in NW Sardinia (Nurra district) that formed at different times in tropical and sub-tropical climates. Both deposits represent palaeosols with deep-weathered residual profiles and overlie Mesozoic carbonate rocks that were deposited on the south European palaeomargin. The older alterite is Cenomanian–Turonian in age and grades upward into a horizon of karstic bauxite, whereas the younger unit occurs within alluvial deposits of Late Neogene age. The Cretaceous palaeosol represents the precursor of the overlying bauxite and formed from unknown sedimentary parent rocks. In contrast, the Messin…
Fluid geochemistry in a low-enthalpy geothermal field along a sector of southern Apennines chain (Italy)
Abstract The chemical and isotopic features of the fluids (water and gases) in the Lucane thermal area (southern Italy) have been investigated in order to verify their origin, water temperature in the geothermal reservoir, and to recognize the main natural processes concerning the water composition during ascent towards the surface. The Lucane geothermal system is placed in the southern sector of the Apennines chains, a seismically active area, close to the southern base of the Mt. Alpi carbonate massif. Along the study area, two main sets of high-angle faults form an almost orthogonal fault system that, as suggested by local structural geology, acts as a preferential pathway for uprising d…
A geochemical survey of the telese hypothermal spring, southern Italy: Sulfate anomalies induced by crustal deformation
This study deals with a chemical survey (major ions and Li+, F–, Br–, and ) on water samples collected from April 1998 to April 1999, from the Telese thermal spring, southern Italy, in order to investigate possible variations in the chemical composition of the spring. Water samples are of the calcium bicarbonate type, with small fluctuations in outlet temperature (20.05 ± 0.23°C), pH (6.23 ± 0.16), and TDS (2415 ± 35 mg/l). The concentrations of major ions stayed nearly constant, except for . All analyzed waters are saturated or oversaturated relative to calcite and dolomite. The higher saturation indices of the water samples relative to calcite and dolomite observed during the summer of 19…