Paleontological evidence for Late Cambrian in the Arburese area, SW Sardinia

Cristiana Ribecai (1) , Gabriella Bagnoli (1) , Francesco Mazzarini (2, 3) , Giovanni Musumeci (1)

1 Dipartimento di Scienze della Terra [Pisa]
2 IGG-CNR - CNR Istituto di Geoscienze e Georisorse [Pisa]
3 INGV - Istituto Nazionale di Geofisica e Vulcanologia – Sezione di Pisa

New palynological investigations allowed a better definition of the age of terrigenous deposits of the Monte Fonnesu tectonic Unit, exposed in the Arburese area (SW Sardinia). The section investigated consists of a coarsening upwards positive sequence, up to 10 m thick, that is made up of quartz-arenitic sandstones and light gray quartzite beds (0.5 m thick), interbedded with thin beds of black shale. In the lower part of the section, two quartzitic levels are rich in lingulid (brachiopods) shell fragments. This is the first report of macrofossils from the Monte Fonnesu Unit. Samples collected for palynological analyses in the black shale at the base and at the top of the lowest quartzitic level yielded a Late Cambrian acritarch microflora that can be correlated with the Peltura trilobite Superzone. The Late Cambrian age assigned to the lower part of the sequence allows us to define more precisely the age of Mt. Fonnesu sandstone, which in consequence is bracketed between the Late Cambrian and the Early Ordovician.

Mots clés: Sardinia; Lower Paleozoic; Late Cambrian; Peltura trilobite Zone; lingulids; acritarchs

Domaines: Stratigraphie

Cristiana Ribecai, Gabriella Bagnoli, Francesco Mazzarini, Giovanni Musumeci. Paleontological evidence for Late Cambrian in the Arburese area, SW Sardinia. Carnets de Géologie / Notebooks on Geology, 2005, CG2005 (M02/08), pp.45-50. ⟨hal-00166893⟩