oa Stratigraphic interpretation of the Cenozoic and Cretaceous succession of Kurdistan, northern Iraq: New evidence from well and outcrop data

Following the successful drilling of the Tawke-1 discovery well in the Dihok PSA licence in Kurdistan, northern Iraq, a sequence of development and appraisal wells have been drilled in the area. Current geological studies are focusing on the integration of regional fieldwork, seismic data, lithostratigraphy, wireline log and biostratigraphic data. In order to improve the understanding of the stratigraphy and intra-field correlation of the study area biostratigraphic analysis has been conducted using ditch-cuttings samples primarily, together with selected field samples. Biostratigraphic analysis employed the integration of quantitative micropalaeontological data (thin section and routine), nannofossil and selected palynological data. Data generated from the current exploration programme, together with unpublished research study data from one of us (SS) suggests that significant revisions of the age of parts of the Cenozoic succession should be considered, vis-à-vis current published ages (van Bellen et al., 1959). The faunal and floral content and age relationships of the Pila Spi, Gercus, Khurmala and Kolosh formations are also described. High-resolution micropalaeontologic and nannopalaeontologic sampling of the Shiranish, Mushora, Kometan, Gulneri, Dokan and Qamchuca formations has refined their ages, and further revisions are suggested to the existing published stratigraphic summary (van Bellen et al., 1959). The application and integration of the biostratigraphic data derived to date (chronostratigraphy and palaeoenvironmental interpretation), to intra-field correlation and regional geology is considered. These new findings provide a strong tool in the continued exploration of the area.