Integrated Micropaleontological/Geochemical (⁸⁷Sr/⁸⁶Sr) Approach to Obtaining Refined Age Control in Fossil Poor Sedimentary Sequences: The Oligocene-to-Pleistocene Calabria-Peloritani Arc, Southern Italy, as a Case Study

Timothy R. Patterson, John Blenkinsop, Eduard G. Reinhardt, William Cavazza

Integration of foraminiferal biostratigraphy, ⁸⁷Sr/⁸⁶Sr isotope stratigraphy and traditional physical stratigraphy has provided a refined age control of a poorly known Oligocene-to-Pleistocene sedimentary sequence covering nonconformably the crystalline basement complex of the Calabria-Peloritani arc, a continental block which rifted off the southern margin of the European plate during Neogene time. In spite of the fossil poor content of the sequence, the simultaneous use of paleontological and geochemical techniques have resulted in the following conclusions. 1) The age of an unnamed, thin calcarenite unit locally present at the base of the sequence, previously considered Rupelian to early Aquitanian in age, has been refined to Chattian (27-26 Ma). This calcaren te was previously considered a basal, conformable member of the overlying Stilo-Capo d'Orlando Formation (SCO Fm.). However, this study indicated that it is separated from the SCO Fm either by an angular uncomformity or by a disconformity representing a significant time interval. 2) The SCO Fm has a latest Chattian/earliest Aquitanian-Burdigalian age. Previously published reports suggested deposition over a much longer time span, ranging from late Rupelian to Langhian. 3) An unnamed deep-marine siliciclastic unit mostly composed of conglomerate and sandstone and previously considered Tortonian in age is, in fact, Serravallian to Tortonian. 4) The depositional interval of the "trubi", fine grained marine deposits, has been independently confirmed to span the Pliocene-Pleistocene.

The results of the study provide a framework for future sequence-stratigraphic and paleotectonic studies in the area, and prove the effectiveness of an integrated paleontological/geochemical (⁸⁷Sr/⁸⁶Sr) approach in the study of fossil-poor sedimentary sequences.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995