The nature of the Cretaceous–Paleogene (K/Pg) boundary in the Kurdistan region of northeastern Iraq is still under debate. Most studies have considered the Danian sediments to be mostly missing. Another hypothesis suggests that a conglomerate represents the contact between the Cretaceous and Paleogene. We examined the succession of the Deramazan and Chinarok sections in Sulaimani area to examine calcareous nannofossil assemblages and the biostratigraphy around the boundary and the Danian sediments; previously, the calcareous nannofossil has not been applied to this sequence. The rock strata in the study sections are characterized by alternations of sandstone, siltstone, shale and marlstone within the Tanjero Formation (late Campanian–Maastrichtian) and the overlying Kolosh Formation (Paleocene–early Eocene). The current study shows that deposition across the boundary in both sections was continuous with no discernible break or pause in sedimentation; it is biostratigraphically delineated by the first occurrences of Biantholithus sparsus, Cruciplacolithus spp. and Coccolithus pelagicus plus an acme of Thoracosphaera operculata of biozone NP1 that indicates no hiatus. The successions in both sections also highlight the occurrence of the early Danian sequence at the bottom of the Kolosh Formation.

中文翻译：

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库尔德斯坦地区/伊拉克苏莱曼尼地区钙质纳米化石的大年沉积物和 K/Pg 边界确定

伊拉克东北部库尔德斯坦地区白垩纪-古近纪（K/Pg）边界的性质仍在争论中。大多数研究认为大年沉积物大部分缺失。另一个假设表明砾岩代表了白垩纪和古近纪之间的接触。我们检查了 Sulaimani 地区的 Deramazan 和 Chinarok 剖面的序列，以检查钙质纳米化石组合以及边界和大年沉积物周围的生物地层；以前，钙质纳米化石尚未应用于此序列。研究剖面中的岩层以 Tanjero 组（晚坎帕阶-马斯特里赫特）和上覆的 Kolosh 组（古新世-早始新世）内的砂岩、粉砂岩、页岩和泥灰岩交替为特征。目前的研究表明，两个剖面的边界沉积都是连续的，没有明显的沉积中断或停顿；它是由 Biantholithus sparsus、Cruciplacolithus spp 首次出现的生物地层划定的。和 Coccolithus pelagicus 加上生物区 NP1 的 Thoracosphaera operculata 的顶点，表明没有间断。两个剖面的序列也突出了 Kolosh 组底部早期大年序列的发生。