Henry Lickorish - Structural Geology
Calgary, Canada
tel: +1 250 213 2643
Evolution of the Agrigento thrust-top basin, Sicily: Sedimentation and the tectonics of orogenic wedges
Butler R.W.H., Keogh S.M. and Lickorish W.H. 1998
Annales Tectonicę, 12, 28-50.

Sedimentary successions are commonly sensitive recorders of tectonic and climatic processes active during and immediately following deposition. Late Neogene sediments in the Agrigento area of Sicily have been used to calibrate climatic signals, particularly associated with the Messinian Salinity Crisis in the Mediterranean and with precession cyclicity through the Pliocene. However, these same successions accumulated within active growth synclines associated with the outer part of the Maghrebian thrust belt in Sicily. Facies vary across fold publications, incicating that variations in palaeo-slope and palaeobathymetry are important tectonic modulators of the sedimentary record. Fold amplification was slow and continuous throughout the Messinian to Early Pleistocene, although the stratigraphic record of active tectonics is highly variable, depending on the nature of the sediments. The area provides a case history for relating facies variations to structural position in thrust-top basins. However, it is still possible to recognise regional signals of climate and eustatic sea-level fluctuations within the sedimentary record. This behaviour is stronly dependent on the slow rate of tectonic deformation. The accumulation of rheologically competent carbonates and gypsum beds may have influenced the tectonic style and, locally, the rate of deformation.