Spicule-rich turbidites are widespread inmid-Cretaceous deep-water flysch of the Subsilesian and Silesian units in the Polish Outer Carpathians. The spicule-rich material with an admixture of numerous radiolarian and foraminiferal particles was supplied, together with siliciclastic material, from shallow environments, mostly from the northern margin of the Carpathian Basin. We present new data on theage of these deposits in the Silesian Nappe, where they are distinguished as the Mikuszowice Cherts. This unit is composed of medium-and thick-bedded siliciclastic to calcareous turbidites including bluish cherts in their middle and upper parts and of thin non-calcareoushemipelagic shales. We have studied radiolaria and foraminifera from hemipelagic sediments and spicule-rich turbidites, from two con-tinuous sections in the Barnasiówka Range (Beskid Wyspowy Mts.) that included the Mikuszowice Cherts (31 m thick) and their transition into the surrounding units. The age of the Mikuszowice Cherts was determined taking into account the following radiolarian datumevents: (1) the occurrence of Praeconocaryomma lipmanaein the entire unit, (2) the FO (first occurrence) of Hemicryptocapsa tuberosain the upper part of the unit, (3) the FO of Amphipyndax stockiclose to the upper boundary of the unit, (4) the FO of Hemicryptocapsa prepolyhedra in the lowermost part of the overlying Barnasiówka Radiolarian Shale Formation. These datum events appear successivelyin the Western Tethys successions within the Rotalipora cushmani planktonic foraminiferal Zone, which corresponds to the middle andupper Cenomanian (except for its uppermost part). The foraminiferal assemblages, in which such taxa as Rotalipora cf.cushmani, R. cf. greenhornensis, whiteinellids and Uvigerinammina praejankoi successively appear, confirm the mid-late Cenomanian age of thespicule-rich turbidites in the Silesian Nappe
