Biostratigraphy and Paleoenvironment of Garagu Formation in Kirkuk well-116, North Iraq

Abstract

The Garagu Formation Tongue has been investigated from biostratigraphic view in one subsurface section in Kirkuk field, well No-116, North Iraq. Many genera and species of benthic foraminifera and calcareous algae have been identified. One assemblage zone has been determined, Pseudocyclammina lituus- Choffatella decipiens assemblage zone (Valanginian - Barremian age). Suggest that age of Garagu Formation (Valanginian- Barremian). Furthermore, the primary and secondary microfacies of the Garagu Formation have been identified that represented by: Pseudocyclammina lituus bearing wackestone submicrofacies, Peloidal lime packstone submicrofacies, oolitic grainstone microfacies, Choffatella decipiens bearing wackestone submicrofacies, oolitic and peloidal packstone submicrofacies, Algal bearing wackestone submicrofacies, and Lime mudstone microfacies. It was established that the formation's paleoenvironment was an open platform (shelf lagoon with restricted platform and platform margin).