Title Age, sedimentation, and soil formation in the Val Sorda loess sequence, northern Italy
Author Ferraro, F.
Author Affil Ferraro, F., University of Milano, Dipartimento di Scienze della Terra "A. Desio", Milan, Italy. Other: University of Milano-Bicocca, Italy; Universita Statale di Milano, Italy; Memorial University of Newfoundland, Canada
Source Quaternary International, 204(1-2), p.54-64, ; INQUA subcommission on European Quaternary stratigraphy, Milan, Italy, Sept. 11-15, 2006, edited by C. Ravazzi, G. Orombelli, M. Donegana, M. Cremaschi and N.R. Catto. Publisher: Elsevier, Oxford, United Kingdom. ISSN: 1040-6182
Publication Date Aug. 1, 2009
Notes In English. 76 refs. GeoRef Acc. No: 307816
Index Terms carbon isotopes; Chernozem; climatic change; glacial deposits; glacial rivers; grain size; isotopes; loess; magnetic properties; paleoclimatology; soil formation; Pleistocene; Quaternary deposits; radioactive isotopes; remanent magnetism; sediments; soils; Italy; anhysteretic remanent magnetization; C-14; carbon; Cenozoic; Chernozems; clastic sediments; climate change; Europe; fluvial environment; glacial environment; glaciofluvial environment; magnetic susceptibility; magnetization; northern Italy; optically stimulated luminescence; paleoenvironment; paleomagnetism; paleosols; pedogenesis; Quaternary; remanent magnetization; Southern Europe; till; upper Pleistocene; Val Sorda; winds
Abstract The Val Sorda sequence is a key section for Quaternary stratigraphy of Northern Italy, because it is very well preserved and is the only loess section in the area providing 14C and luminescence dating. The base of the succession consists of a till, capped with a rubefied Eemian palaeosol. It is overlain by a colluvial layer and by a thick loess unit, including three chernozem palaeosols, formed during MIS 4 and 3. The sequence is capped and preserved by fluvioglacial and glacial deposits (MIS 2). Grain-size analysis of each single sand and silt fraction from the loess reveals that it can be used as a proxy of wind energy with higher amounts of coarser fractions corresponding to stronger winds; grain-size zones are identified showing cycles of variations in aeolian dynamics. Chernozems occur at grain-size zone boundaries, corresponding to changes in wind strength. Among heavy minerals, the ultradense fraction also represents a wind proxy, fitting with the identified grain-size zones, higher percentages indicating higher wind intensities. Although the Val Sorda sediments have the same provenance, the glacial and aeolian units are characterized by different heavy mineral assemblages. The loess unit is marked by the presence of garnet, while in both tills amphiboles are common. Magnetic parameters here considered confirm their role of palaeoclimatic proxies, similarly to that proposed for many loess sequences: MS and ARM values fit with the identified grain-size zones; higher values correspond to higher wind intensities. #2Xfd% is sensitive to ultrafine SP particles, confirming its role as a pedogenesis proxy.
URL http://hdl.handle.net/10.1016/j.quaint.2008.12.002
Publication Type conference paper or compendium article
Record ID 65004854