Analyses of rock clasts and of heavy minerals in upper Miocene coarse detrital units drilled along the East Sardinia passive-type continental margin (Sites 654, 653, 652, and 656) reveal that the stretched basement contains quite complex rock suites. Taking also into account previous sampling data, in moving from west to east across the margin, the nature of the basement changes drastically.To the west there are mostly Hercynian basement rocks with their cover, referable to the alpine foreland of the Corsica-Sardinia block. To the east, along the lower margin, where crustal thinning is quite severe, the basement contains rock suites referable to a pre-upper Tortonian orogenized zone with units constituting parts of the Alpine and Apenninic chains (presumably with thickened continental crust prior to stretching). Largest thinning and ocean forming occurred then, in a rather short time, mostly at the expense of unstable crust just thickened by orogenetic/tectogenetic processes.

AA = abundant, A = less abundant, P = present, T = trave, ? = doubtful, - = absent

Supplement to: Sartori, Renzo; Mascle, Georges; Bouillin, Jean-Pierre; Girault, J; Naud, G; Pasini, M; Piboule, M (1990): Types and sources of large rock clasts and of heavy minerals from ODP Sites 652, 653, 654, and 656 in the Tyrrhenian Sea: implications about the nature of the East Sardinia passive continental margin. In: Kastens, KA; Mascle, J; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 107, 29-35