A soil chronosequence study of the Reno valley, Italy: Insights into the relative role of climate versus anthropogenic forcing on hillslope processes during the mid-Holocene

摘要: Abstract Relatively few soil chronosequences with good age control exist for Late Pleistocene and Holocene deposits in the Mediterranean region of Europe, yet surface soils their young buried counterparts can provide meaningful information about timing processes landscape response to external forcing such as climate or anthropogenic change. Here we present results a study that examines well-dated chronosequence nineteen exposures surficial ranging from hundreds years thousands located Reno River Valley near Bologna, Italy. The soil-forming sits on threshold between which facilitates accumulation CaCO3 translocation formation clay minerals iron oxides. Once formed, secondary oxides are relatively immobile oxidizing conditions profile therefore consistently record trends, Feo/Fed ratios decreasing predictably all chronosequence. morphology carbonate its depth leaching also vary age, but only younger than ~ 12,000 years. In these soils, horizons contain progress shallow, Stage I Bk late Holocene-aged deeper III latest-Pleistocene aged soils. older approximately 12,000 cal ybp, however, dissolution during wetter climates addition colluvium and/or dust terrace surfaces become important factors preservation profile, content is not predictable by alone. Without significant depositional additions, decalcified. Pedogenic precipitated drier susceptible periods, evidenced discontinuous coatings grains some Therefore overall measurable pedogenic spatially temporally variable function input fresh locally-controlled moisture conditions. Particle size does decrease appears be strongly influenced parent material variability additions Our detailed examination stratigraphy revealed evidence aggradation tributary fans middle ~ 6000 ~ 4000 ybp. This pre-dates Bronze Age agricultural expansion, instead attributable have been documented elsewhere Italy this time period. demonstrates Europe effectively help elucidate rates evolution.