I detriti di versante ai margini della Piana del Fucino (Italia centrale): Significato paleoclimatico ed impatto antropico

Abstract

The slope waste deposits outcroppig in the studied area of the Fucino Plain consist of 5 formations. Deposits are dated with ¹⁴C and thermoluminescence, and through artefacts and pottery remains found in the scree. 1) The 1st Formation, formed during two sedimentation phases at least, is younger than 20,000 years ago and older than the rise of the lake Fucino level, which occurred before the deposition of the 2nd Formation. 2) The 2nd Formation formed during 3 phases, separated by 2 periods of prevailing pedogenesis; the bottom of this formation is a little older than the deposition of a tephra layer, dated to 14,000 years ago; the middle and the top portions include layers having ¹⁴C ages of 11,640±70 and 10,730±100 years BP, respectively. The formation is covered by a soil developed during the first half of the Holocene the 2nd Formation is attributed to the Late Glacial period. 3) The 3rd Formation covers a soil containing Neolithic pottery; yherefore it is younger than approx. 5,000 years BP. 4) The 4th Formation contains fragments of reworked pottery dated back to 4,670±430 and 2,783±213 years BP by thermoluminescence, and is older than the artefacts dated a few centuries B.C. 5) The 5th Formation covers or includes Roman Imperial and more recent pottery. The deposition of the waste is linked to phases during which the vegetation cover on the slope was scanty. During pre-Holocene times changes in the vegetation cover are indicative of climatic variations only, while in the second half of the Holocene vegetational changes might be affected both by climatic variations and human impact. During this latter period traces of man are also found on slopes above scree deposits and a reduction of vegetation might be one of the effects. Nevertheless, the chronological correlation between phases of scree accumulation and of decrease in level of lake Fucino suggests that environmental changes were mostly linked to drier climatic periods.