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High-frequency cyclicity in the latest Messinian Adriatic foreland basin: Insight into palaeoclimate and palaeoenvironments of the Mediterranean Lago-Mare episode
No full textLate Messinian Lago-Mare deposits show high-frequency cyclicity in the whole Mediterranean Basin. Both millimeter- and
centimeter-scale cyclicities have been observed in several ODP sites as well as in stratigraphic sections from the Mediterranean
borderland. We have analyzed a well-exposed late Messinian Lago-Mare section from the Adriatic side of the central Apennines
(Italy). At the Fonte dei Pulcini section (SE Majella Mts.), millimeter- and centimeter-scale white-and-dark couplets have been
observed in the field. A 50 cm regular-spaced sampling has been performed in the uppermost 53 m of the late Messinian Lago-
Mare clays. On the 107 collected samples, geochemical (CaCO3 content), mineralogical (XRD analyses), and micropalaeontological
investigations have been performed. In addition, SEM and microprobe investigations as well as mineralogical
and micropalaeontological analyses have been carried out on single lamina from a 34-cm-thick interval of millimeter-scale
laminites.
Besides the 103 cycles/m and 102 cycles/m frequencies observed in the field, spectral analyses performed on the CaCO3 data
set indicated other high-frequency cyclicities: 0.47 cycles/m, 0.35 cycles/m, and 0.17 cycles/m. Taking into account the
estimated sedimentation rate, these frequencies correspond, respectively, to periodicities of: 1 year, 10 years, 2.1 kyr, 2.8 kyr,
and 5.6 kyr. These sub-Milankovitch cyclicities have been related to annual and sunspot solar activity.
The millimeter-scale couplets are interpreted as varves sedimented in an ephemeral water environment marginal to a
perennial brackish water lagoonal basin. These varved sediments reflect a marked seasonality characterized by the alternation of
arid and more humid climatic phases. The presence of high values of smectite (60–80%) in the clay minerals of the analyzed
samples could be a consequence of these climatic oscillations from drier to moister conditions. The climatic scenario suggested
in this paper for the late Messinian Lago-Mare episode is in agreement with the monsoon system that, according to some
authors, starting from 5.8 Ma developed in the Mediterranean area
Metodo Ufficiale n°IV.2 - Diffrattometria a raggi X. Analisi mineralogica semiquantitativa.
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ACCELERATED AGEING OF INCINERATOR BOTTOM ASH AS A TOOL FOR LANDFILL MANAGEMENT OPTIMIZATION
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Engineering and environmental properties of thermally treated mixtures containing MSWI fly ash and low-cost additives
No full textAn experimental work was carried out to investigate the feasibility of application of a sintering process to mixtures composed of Municipal Solid Waste Incinerator (MSWI) fly ash and low-cost additives (waste from feldspar production and cutlet). The proportions of the three constituents were varied to adjust the mixture compositions to within the optimal range for sintering. The material was compacted in cylindrical specimens and treated at 1100 and 1150degreesC for 30 and 60 min.
Engineering and environmental characteristics including weight loss, dimensional changes, density, open porosity, mechanical strength, chemical stability and leaching behavior were determined for the treated material, allowing the relationship between the degree of sintering and both mixture composition and treatment conditions to be singled out.
Mineralogical analyses detected the presence of neo-formation minerals from the pyroxene group.
Estimation of the extent of metal loss from the samples indicated that the potential for volatilization of species of Pb, Cd and Zn is still a matter of major concern when dealing with thermal treatment of incinerator ash
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