Stratigraphic Evidence for Crustal Thickness Changes on the Southern Tethyan Margin during the Alpine cycle

APPENDIX I. EVIDENCE FOR THE INITIAL PRESENCE OF NORMAL CONTINENTAL CRUST Many of the Mesozoic and lower Tertiary sedimentary sequences of Tunisia, Sicily, the Apennines, the Southern Alps, the Dinarides, and the Hellenides are interpreted as having been deposited on continental crust of the margin of Africa or of the African Adriatic Promontory (Argand, 1924; Bernoulli and Jenkyns, 1974; D'Argenio, 1976; Channeli and others, 1979; Catalano and others, 1976). This is in contrast to be ophiolites and related sedimentary rocks that bear witness to the former presence of the Mesozoic-early Tertiary oceanic area of the Tethys farther to the north, west, and east (Fig. 1, in main text). The former sequences, dominantly carbonates, rest in many areas on Triassic clastic and evaporitic sequen*** and their pre-Triassic substratum is known in some places. Well data show that Paleozoic sedimentary rocks as ol*** as Cambrian underlie the Mesozoic seque*** in Tunisia (Burollet, 1967); continents crust would almost certainly be found at greater depth. In the Southers Alps the carbonate sequences rest on the Austroalpine and Southern Alpine crystalline basement, which was clearly continental crust during the Mesozoic. In the Dinarides, some exposures of continental crust are known beneath the carbonate sequences (Dimitrievic, 1974). © 1980 The Geological Society of America, Inc.