Bornova Flysch Zone (BFZ) comprises several olistoliths or tectonic slivers, representing the lithosphere of the Izmir-Ankara Ocean and accretionary melange complexes formed during its closure. Radiolarian assemblages in one of the olistoliths in BFZ, to the NE Manisa city, between Akhisar and Sindirgi towns, is studied along Sogutlu stratigraphic section in detail. Sogutlu section is 73,5 m thick and composed of green to red, mainly thin to medium-bedded chert and mudstone alternation. Ten samples out of eighteen yielded relatively diverse radiolarian assemblages.
Basalmost part of the section contains characteristic latest Bajocian – early Callovian radiolarian taxa (Acanthocircus suboblangus suboblangus (Yao), Higumastra sp., Tritrabs ewingi s. l. (Pessagno), Acaeniotyle diaphorogona s. l. Foreman, Hsuum sp., Crubus sp., Ristola altissima major Baumgartner & De Wever, Mirifusus fragilis s. l. Baumgartner, Spongocapsula sp., Parvicingula sp., Podobursa helvetica (Rüst), Podobursa sp., Sethocapsa sp. A sensu Baumgartner, Stichocapsa spp. and Eucyrtidiellum unumaense s. l. (Yao)). Succesively, radiolarian assemblages indicating Late Jurassic, early Early Cretaceous and late Early Cretacous and early Late Cretacous time intervals have been obtained from the section. Youngest radiolarian assemblage yielded from the section includes diverse radiolarian taxa (Dactyliosphaera silviae Squinabol, Pseudoaulophacus sp., Godia sp., Rhopalosyringium sp., Dictyomitra spp., Dictyomitra crassispina (Squinabol), Pseudodictyomitra pentacolensis Pessagno, Pseudodictyomitra pseudomacrocephala (Squinabol), Xitus spp., Novixitus mclaughlini Pessagno and Stichomitra communis Squinabol) and these taxa clearly reveals the late Cenomanian age.
Previous studies reveal that the Izmir-Ankara oceanic basin was initially opened during late Ladinian – early Carnian. The new radiolarian data obtained from this olistolith reveals that relatively condensed, continuous pelagic sedimentation took place in this basin during the latest Bajocian to late Cenomanian time span.