The loess-paleosol sequence at Monte Netto: a record of climate change in the Upper Pleistocene of the central Po Plain, northern Italy

Purpose At the northern fringe of the Po Plain (northern Italy), several isolated hills exist, corresponding to the top of Late Quaternary anticlines. These hills were thoroughly surveyed for their soils and surficial geology, furnishing detailed archives of the palaeoenvironmental evolution of the area. A new, thick and complex loess-paleosol sequence, resting upon fluvial/fluvioglacial deposits, exposed in a quarry at the top of the Monte Netto hill was studied in detail to elucidate its significance. Materials and methods Highly deformed fluvial and fluvioglacial deposits, probably of Middle Pleistocene age, are exposed in a clay pit at Monte Netto, underneath a 2- to 4-m-thick loess-paleosol sequence. A geopedological, sedimentological and micropedological investigation of the sequence shows a distinctive difference between the B horizons forming the sequence, while luminescence and radiocarbon age determinations and the occurrence of Palaeolithic lithic assemblages elucidate the chronology of the sequence. Results and discussion The pedosedimentary sequence consists of several loess layers showing different degrees of alteration; loess deposition and weathering occurred, according to optically stimulated luminescence (OSL) and AMS-14C dating as well as archaeological materials, during the Upper Pleistocene. The lower part of the section consists of strongly weathered colluvial sediments overlying fluvial and fluvioglacial sediments. A tentative model of the exposed profiles involves the burial of the anticline, which forms the core of the hill, by loess strata since Marine Isotopic Stage (MIS) 4 and their subsequent weathering (and truncation) during subsequent interstadials. The degree of weathering of buried B horizons increases from the top of the sequence toward the bottom, suggesting a progressive decrease in the intensity of pedogenesis. Finally, the highly rubified paleosol at the top of the hill is regarded as a buried polygenetic soil or a vetusol, developed near the surface since the Middle Pleistocene. Conclusions The palaeopedological, geochronological and geoarchaeological analyses permit to define the phases and steps of development of the Monte Netto pedosedimentary sequence; the lower part of the sequence is dated to the Mid-Pleistocene, whereas loess accumulation occurred between MIS 4 and MIS 2. Moreover, analyses help to clarify the climatic and environmental context of alternating glacial and interstadial phases, during which the sediments where deposited, deformed and weathered

Late Pleistocene climate change and landscape dynamics in the Eastern Alps: the inner-alpine Unterangerberg record (Austria)

Drill cores from the inner-alpine valley terrace of Unterangerberg, located in the Eastern Alps of Austria, offer first insights into a Pleistocene sedimentary record that was not accessible so far. The succession comprises diamict, gravel, sand, lignite and thick, fine grained sediments. Additionally, cataclastic deposits originating from two paleo-landslide events are present. Multi-proxy analyses including sedimentological and palynological investigations as well as radiocarbon and luminescence data record the onset of the last glacial period (Würmian) at Unterangerberg at ∼120–110 ka. This first time period, correlated to the MIS 5d, was characterised by strong fluvial aggradation under cold climatic conditions, with only sparse vegetation cover. Furthermore, two large and quasi-synchronous landslide events occurred during this time interval. No record of the first Early Würmian interstadial (MIS 5c) is preserved. During the second Early Würmian interstadial (MIS 5a), the local vegetation was characterised by a boreal forest dominated by Picea, with few thermophilous elements. The subsequent collapse of the vegetation is recorded by sediments dated to ∼70–60 ka (i.e. MIS 4), with very low pollen concentrations and the potential presence of permafrost. Climatic conditions improved again between ∼55 and 45 ka (MIS 3) and cold-adapted trees re-appeared during interstadials, forming an open forest vegetation. MIS 3 stadials were shorter and less severe than the MIS 4 at Unterangerberg, and vegetation during these cold phases was mainly composed of shrubs, herbs and grasses, similar to what is known from today's alpine timberline. The Unterangerberg record ended at ∼45 ka and/or was truncated by ice during the Last Glacial Maximum

Age, soil-forming processes, and archaeology of the loess deposits at the Apennine margin of the Po plain (northern Italy): New insights from the Ghiardo area

The significance of two loess profiles located in the Ghiardo area (Reggio Emilia, northern Italy) along the southern margin of the Po Plain is discussed on the basis of sedimentary and pedological data, optically stimulated luminescence (OSL) dating, and archaeological context. Loess sedimentation occurred during cold and arid glacial and stadial periods of the Upper Pleistocene, between c. 70 and 35ka. In the same time interval, loess sedimentation occurred at other localities at the northern margin of the Po Plain (Po Plain Loess Basin). The early period of loess sedimentation was contemporary with an intense frequentation of the area by Palaeolithic hunters, whose remains, consisting of clusters of flint artefacts, are found at the base of the loess sequences. Thermoluminescence dates on burned flints are consistent with OSL measurements on sediments where lithics were found and therefore the archaeological finds may be attributed to the Middle Palaeolithic lithic complexes of the Mousterian culture. Subsequent soil-forming processes on the loess deposits during the Holocene are suggested by changes in the proprieties of the profiles (clay illuviation, hydromorphic and vertic features, mukkara/gilgai microrelief). Degradation processes of the topsoil, leading to the formation of an eluvial top horizon, were eventually triggered by deforestation, which took place in the area since the Chalcolithic period (middle Holocene).SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Age, soil forming processes, and archaeology of the loess deposits at the Apennine margin of the Po Plain (Northern Italy). New insights from the Ghiardo area.

The significance of two loess profiles located in the Ghiardo area (Reggio Emilia, northern Italy) along the southern margin of the Po Plain is discussed on the basis of sedimentary and pedological data, optically stimulated luminescence (OSL) dating, and archaeological context. Loess sedimentation occurred during cold and arid glacial and stadial periods of the Upper Pleistocene, between c. 70 and 35 ka. In the same time interval, loess sedimentation occurred at other localities at the northern margin of the Po Plain (Po Plain Loess Basin). The early period of loess sedimentation was contemporary with an intense frequentation of the area by Palaeolithic hunters, whose remains, consisting of clusters of flint artefacts, are found at the base of the loess sequences. Thermoluminescence dates on burned flints are consistent with OSL measurements on sediments where lithics were found and therefore the archaeological finds may be attributed to the Middle Palaeolithic lithic complexes of the Mousterian culture. Subsequent soil- forming processes on the loess deposits during the Holocene are suggested by changes in the proprieties of the profiles (clay illuviation, hydromorphic and vertic features, mukkara/gilgai microrelief). Degra- dation processes of the topsoil, leading to the formation of an eluvial top horizon, were eventually triggered by deforestation, which took place in the area since the Chalcolithic period (middle Holocene)

Estudo sobre a defosforilação da GFAP em fração citoesquelética de hipocampo de ratos

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