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Late Quaternary environmental evolution of the intermontane

Valle Caudina basin, southern Italy

 

Pennetta Micla1, Donadio Carlo1, Russo Filippo2

 
1 Department of Earth Sciences, Environment and Resources, University of Naples Federico II, Largo San Marcellino 10, 80138 Naples, Italy
2Department of Science and Technology, University of Sannio, 59/A Via dei Mulini, 82100 Benevento, Italy
 
Rendiconti Lincei Scienze Fisiche e Naturali, 2014, 25:231-240
 
Abstract
The Valle Caudina intermontane basin in the southern Apennines (Italy) lies between the Mt. Taburno on the North and the Avella-Partenio mountains on the South. An analysis of its present-day landscape, and of its stratigraphic and geoarcheological features, has been carried out to reconstruct the Late Quaternary evolution of the basin, filled by alluvial, colluvial and volcaniclastic deposits. The depositional pattern and geomorphological context allow to recognize lacustrine and fluvial-lacustrine sediments, interbedded with ignimbritic layers originating from the Phlegrean Fields and with a Vesuvius pumice level, that represent significant chronological markers. The two lacustrine episodes are connected with volcanic events radiometrically dated (De Vivo et al. 2001). The older predates the Campanian Ignimbrite deposit (~39 kyr BP), while the younger deposited before 5 kyr BP, as indicated by the recovery of Neolithic artifacts. The presence of Roman ruins in the center of the valley suggests that the lake has suffered a substantial downsizing or has disappeared between 5 kyr BP and the Roman Age. A clayey deposit testifies a first lacustrine phase, which has affected the whole plain. Above this unit, heterogeneous deposits indicate the end of the lacustrine phase and the beginning of a clear fluvial sedimentation. Volcaniclastic deposits from the erosion of the Campanian Ignimbrite follow. They are overlapped by a widespread second lacustrine unit. Finally, a reworked and altered volcaniclastic level closes the stratigraphic sequence, while particularly fertile topsoil covered all the plain.
 
Key-words: Geomorphology, Intermontane basins, Quaternary, Southern Apennines, Italy
 
Fig. 1 – A: Geomorphological map of Valle Caudina. 1) contour line (m a.s.l.); 2) altitude (m a.s.l.); 3) watershed; 4) subsequent drainage; 5) limit of fluvial terrace;6) fluvial terrace: (a) first and (b) second order; 7) alluvial fan; 8) hanging valley; 9) polje; 10) fault scarp: a) retreating, b) rejuvenated; 11) palaeosurface: a) summital, b) downlifted; 12) landslide pile; 13) basin depocenter; 14) palaeotreshold. B: The three main phases of morphoevolution and sedimentary cycles occurred (the volcanological markers of continental paleoenvironments are highlighted in gray, the solid star indicates archeological remains); C continental; T transition paleoenvironments: subscript L lacustrine, F fluvial, FL fluvial-lacustrine, V volcaniclastic; climate: R-W Riss-Würm interglacial, W Würm glacial (from I to IV) and relative interstadial phases, HCO Holocene climate optimum, CWP cool wet period, RWP Roman warm period; units: BC Basal Clay, AT Ancient Tuff, LI lacustrine I, AF alluvial fan, FL fluvial-lacustrine, CI Campanian Ignimbrite, LII lacustrine II, AP Avellino Pumices, RP reworked pyroclastics stratigraphy, c clay, s sand, g gravel; cycles: A pre-ancient Tuff, B post-ancient Tuff - pre-Campanian Ignimbrite, C post-Campanian Ignimbrite