Skip to main content
Passa alla visualizzazione normale.

MAURO AGATE

Tectonics, climate and deposition/erosion cycles during the Quaternary in Western Sicily

  • Authors: Agate, M; Basilone, L; Catalano, R; Di Maggio, C
  • Publication year: 2011
  • Type: eedings
  • Key words: Sedimentation and tectonics
  • OA Link: http://hdl.handle.net/10447/58430

Abstract

Continental to marine Quaternary deposits outcrop in thin and patchily exposed successions in Western Sicily, overlying a previously deformed substrate, known as the Neogene-Early Quaternary chain. These deposits are grouped in sedimentary units bounded by unconformity surfaces. The detected unconformities, often of regional extent, allows us to define seven main synthems: a) Marsala synthem is a Lower Pleistocene 2-80 m-thick body of marine/coastal calcarenites; b) Piana di Partinico synthem is made up of 1-5 m thick marine/continental clastics located on several marine terraces related to sea level highstand phases of Middle Pleistocene (Oxygen Isotope Stages – OISs - 17-7); c) Polisano synthem consists of aeolian sands, 1-10 m-thick, of late Middle Pleistocene (OIS 6); d) Barcarello synthem encompasses 1-2 m thick marine/coastal deposits, laterally passing into 1-5 m thick colluvial deposits, whose age is correlated with the OIS 5; e) Imera Settentrionale synthem is made up of Middle–Upper Pleistocene 1-3 m-thick fluvial deposits located on river terraces; f) Raffo Rosso synthem is composed of aeolian sands, colluvial, gravitational and stratified slope deposits (OISs 4-2); g) Capo Plaia synthem consists of coastal to continental deposits of Holocene age (OISs 2-1). The processes of deposition or erosion producing sedimentary bodies or unconformity surfaces, respectively, seem to be triggered by significant environmental changes due to tectonic movements and climatic fluctuations. The interplay of these factors suggests the following evolution: a Lower Pleistocene block faulting induced displacements of hundreds of meters allowing the development of marine erosion transgressive surfaces and shallow-water sedimentation of the Marsala synthem; the interplay between tectonic uplifting and sea level highstand phases, during Middle-Late Pleistocene, gave rise to several orders of marine and river terraces, where the Piana di Partinico, Barcarello and Imera Settentrionale synthems deposited. In this period, aeolian and stratified slope deposits of Polisano and Raffo Rosso synthems were accumulated above non-depositional surfaces, during cold climatic events; the triggering of strong sheet erosion and sheet flood produced subaerial erosion surfaces and colluvial deposits of the Piana di Partinico, Barcarello and Raffo Rosso synthems, during semi-arid climatic events.