Palaeozoic (Silurian and Devonian) radiolarians and conodonts from chert olistoliths of the Volissos Turbidites, Chios island, Greece

Abstract

The Volissos Turbidites (also known as Chios Mélange) are a thick Palaeozoic wildflysch sequence that crops out on the Greek island of Chios. It consists of chert, limestone and volcanic olistholits floating in a siliciclastic turbiditic matrix. During the Early Carboniferous (Mississippian), these turbidites were severely deformed and structurally thickened probably at the toe of an accretionary wedge. Whereas there are many studies on the fossiliferous content of the limestone olistoliths, scant attention was given to the cherts. We report here for the first time some radiolarian and conodont assemblages from the chert olistholiths (ribbon radiolarites) embedded in the siliciclastic sequence of the Volissos Turbidites. The radiolarites sam pled near Kardamila and Marmaro (northeastern Chios), where the Volissos Turbidites are not affected by metamorphism, have given identifiable radiolarians and conodonts. The different samples document different ages. Some radiolarians document Silurian, possible Pridolian age, whereas the conodonts indicate a distinct Famennian (late Late Devonian). The radiolarians of other samples delineate a more general range (Devonian-?Early Carboniferous).