Cretaceous / Paleogene Boundary Analysis by PlankticForaminiferal Biozonation in the Western Zagros Fold-Thrust Belt (Smaquli valley), Sulaimani Governorate,NE-Iraq

The current work focuses to study the foraminifera assemblages within thecretaceous/paleogene (k/pg) boundary outcropped in the high folded zone in smaqulivalley (gali section), kurdistan region, and northeastern iraq. the boundary is nearlylocated between tanjero and kolosh formations and their exposure mainly consists of thicksuccession of deep marine turbidities (flysch) and hemipelagic sediments. the study aims toindicate biological fossils assemblages and physical expressions that inherited from globallyimportant events of the end of cretaceous. the study has extraited expressions of the wellexposed successions of fine grains from which 8 biozones are identified in the uppermostsection of shiranish formation, the shiranish- tanjero transition area and the tanjeroformation through biostratigraphy (biozonation) and lithostratigraphic analyses. these zones,from the bottom to top, are upper part of globotruncana aegyptiaca interval zone (cf8),which belongs to upper part of shiranish formation, (early maastrichtian) and lower part oftanjero formation. the second, third, fourth and fifth zones are gansserina gansseri intervalzone (cf7), contusotruncana contusa interval zone (cf6) (early maastrichtian) andpseudotextularia intermedia interval zone (cf5), racemiguembelina fructicosa interval zone (cf4) respectively and all belong to lower part of tanjero formation (earlymaastrichtian). the sixth, seventh and eighth zones are pseudoguembelina hariaensis intervalzone (cf3), pseudoguembelina palpebra interval zone (cf2), plummerita hantkeninoidestotal range zone (cf1) respectively that belong to upper part of tanjero formation (latemaastrichtian). moreover, four biozones of danian (early paleocene) are recorded in thelower part of kolosh formation which are guembelitria cretacea interval zone (p0), (base ofdanian), parvularugoglobigerina eugubina total range zone (pα), (base of danian),parvularugoglobigerina eugubina-subbotina triloculinoides interval zone (p1a) (earlydanian), subbotina triloculinoides–praemurica inconstans interval zone (p1b), (middledanian). the lithostratigraphic and biostratigraphic study revealed that no physical events(conglomerate, erosional surface, paleosoil and hardground) and has a conformable andgradational existence, which is evidenced by continuous sedimentation of the same sedimentsand no chronostratigraphic gaps within k / pg boundary. biologically, it shows the gradualextinction of the cretaceous planktic foraminifera and the sudden emergence of the paleogeneones