Upper Cretaceous-middle Eocene aged olistrostromal pelagic units in the Biga Peninsula (NW Anatolia); Balıkkaya formation

Indexed In

Volume 164 / 2021

Authors:

Serdar AKGÜNDÜZ, İzver ÖZKAR ÖNGEN

Keywords:

Balıkkaya formation, Biga Peninsula, pelagic foraminifera, Late Cretaceous-middle Eocene, extensional tectonic regime

Abstract:

Balıkkaya formation consists of olistostromal units with a burgundy coloured mudstone, siltstone and   pelagic   limestone   matrix   containing   various   sizes   of   UpperJurassic-Lower Cretaceous limestone  (Bilecik  Limestone)  blocks  and  Triassic  Karakaya  Complex  blocks, which  crop  out in the west, south and southwest of Biga Town in Biga Peninsula (NW Anatolia). The matrix of Balıkkaya formation,  of  which  age  and  sedimentary  environment  are  controversial, contains Late Cretaceous (Maastrichtian) Abathomphalus mayaroensis (Bolli), Abathomphalus sp., Rosita fornicata (Plummer),  Globotruncanidae,  early  Paleocene  (Danian)  Morozovella  pseudobulloides (Plummer), late Paleocene (Thanetian) Morozovella velascoensis (Bolli), early Eocene Acarinina pentacamarata   (Subbotina),   middle   Eocene   Turborotalia   frontosa   (Subbotina),   Turborotalia cerroazulensis (Cole), Orbulinoides beckmanni (Saito),  Hantkenina sp. pelagic foraminifera and Radiolariafossils representing the deep marine environment. These paleontological, lithological and sedimentological data obtained from Balıkkaya formation show that Balıkkaya formation developed in a deep marine environment under tectonic control starting from Late Cretaceous and ending in early-middle Eocene. This pelagic unit indicates the presence of a extensional tectonic regime on the Biga Peninsula and the fault activity along the southeastern edge of the Thrace Basin in the Late Cretaceous-Middle Eocene time interval.

https://doi.org/10.19111/bulletinofmre.719876

 

DOI:

https://doi.org/10.19111/bulletinofmre.719876