THE NOCELLA CONGLOMERATES: A PROBLEMATIC OUTCROP HIGHLY SUSPENDED ON THE SOUTHERN SLOPE OF THE EASTERN SORRENTO PENINSULA (ITALY)

Abstract

A 130m thick sedimentary alluvial to slope deposits (Nocella Formation) rests on a concave up spur suspended between 660m and
800m on the southern coastal slope of the Sorrento Peninsula have been analized. Stratified slope waste deposits (Nocella breccias)
unconformably and abruptly rest on Nocella alluvial deposits (Nocella Conglomerates). Facies analysis of the Nocella Conglomerates
indicate a high-energy, gravel bed braided environment. In particular two facies association have been distinguished. The first one is
representative of in-channel deposition and both vertical accretion and lateral and downstream migration of gravel bars. The second
one reflect vertical accretion and downstream migration of low-relief gravel bars and extensive, locally in-channel, deposition by highenergy flood flows respectively. Paleocurrent data indicate a WNW-sloping paleoslope away from a, nowadays, lacking highland.
Techniques of lateral profile analysis and hierarchical ordering of bounding surfaces has also been applied to the Nocella
Conglomerates, and allows two different river model to be outlined.
Slope deposits also taper upslope coating a triangular facet belonging to the first fault scarp generation which occurred after the formation of the I order palaeosurface sailed by Nocella Conglomerates; they are cut by the second fault scarp generation together with relics of the II order palaeosurface such as the Agerola karst basin and the S.Maria del Castello erosional surface. We correlate the Nocella alluvial deposits with the S. Maria del Castello relic of II order palaeosurface and thus we propose a reconstruction of a part of the Sorrento Peninsula Early Pleistocene landscape. The source area of the Nocella Conglomerates should be a mountainous area located east-southeastward of Nocella site and should be the same as, on the opposite side, fed the clastic infilling of the Agerola karstic basin.