Stratigraphy and Microfacies of Cretaceous Limestones in the Bornova Flysch Zone (Spil Mountain, Manisa, Western Turkey)

Abstract

Spil Mountain (Manisa, western Turkey) is situated in the Bornova Flysch Zone, which is bounded by the İzmir–Ankara Suture Zone (northern branch of Neo-Tethys) to the northwest and by the Menderes Massif to the southeast. The purpose of this study is to describe microfacies and microfossil assemblages of the Spil Mountain carbonate sequences. Two carbonate sequences in autochthonous and allochthonous settings are differentiated. The autochthonous sequence begins with inner-platform carbonates of Early Cretaceous age, which are represented by algal wackestone, fenestral mudstone, intraclastic packstone with Praechrysalidina infracretacea, Salpingoporella annulata, and charophyte oogonia. The platform succession is disconformably overlain by calciclastic turbidites and pelagic wackestones of Maastrichtian age, representing platform drowning, and then passes upward into siliciclastic sediments containing large limestone blocks. Allochthonous carbonate sequences range in age from the?Cenomanian to Santonian–early Campanian, and were deposited in peritidal to outer-shelf palaeoenvironments. The lower part of the allochthonous sequence is composed of foraminiferal–intraclastic wackestones–packstones with mainly miliolids and Cuneolina pavonia. The middle part consists of peloidal wackestone/packstone with Aeolisaccus, Thaumatoporella, benthic foraminifers, and rudist shell fragments. The benthic foraminifera are represented by Pseudocyclammina sphaeroidea, Keramosphaerina tergestina, Moncharmontia apenninica/compressa, and Scandonea samnitica. In the upper part of the allochthonous sequence, pelagic wackestone with Marginotruncana and Dicarinella is alternated with foraminiferal–peloidal packstone with rudist shell fragments and microbioclastic wackestone.