Late-Quaternary paleoenvironmental evolution of Lesina lagoon (sosuthern Italy) from subsurface data

TitleLate-Quaternary paleoenvironmental evolution of Lesina lagoon (sosuthern Italy) from subsurface data
Publication TypeJournal Article
Year of Publication2006
AuthorsLucchi, MRicci, Fiorini, F, Colalongo, MLuisa, Curzi, PVittorio
JournalSedimentary Geology
Volume183
Pagination1-13
KeywordsForaminifers, Late Quaternary, Lesina lagoon (Italy), Ostracods, Sea-level changes
Abstract

Integrated sedimentological and micropaleontological (foraminifers and ostracods) analyses of two 55 m long borehole cores (S3 and S4) drilled in the subsurface of Lesina lagoon (Gargano promontory—Italy) has yielded a facies distribution characteristic of alluvial, coastal and shallow-marine sediments. Stratigraphic correlation between the two cores, based on strong similarity in facies distribution and AMS radiocarbon dates, indicates a Late Pleistocene to Holocene age of the sedimentary succession.

Two main depositional sequences were deposited during the last 60-ky. These sequences display poor preservation of lowstand deposits and record two major transgressive pulses and subsequent sea-level highstands. The older sequence, unconformably overlying a pedogenized alluvial unit, consists of paralic and marine units (dated by AMS radiocarbon at about 45–50,000 years BP) that represent the landward migration of a barrier-lagoon system. These units are separated by a ravinement surface (RS1). Above these tansgressive deposits, highstand deposition is characterised by progradation of the coastal sediments.

The younger sequence, overlying an unconformity of tectonic origin, is a 10 m-thick sedimentary body, consisting of fluvial channel sediments overlain by transgressive–regressive deposits of Holocene age. A ravinement surface (RS2), truncating the transgressive (lagoonal and back-barrier) deposits in core S4, indicates shoreface retreat and landward migration of the barrier/lagoon system. The overlying beach, lagoon and alluvial deposits are the result of mid-Holocene highstand sedimentation and coastal progradation.

DOI10.1016/j.sedgeo.2005.09.003