Abstract The taxonomic composition and detailed stratigraphic distribution of the calcareous nannofossils from the Santonian and Campanian of the Crimea have been studied for the first time. The identified assemblage of calcareous nannofossils in the Alan-Kyr section consists of 85 species, including all primary and additional zonal markers. The following calcareous nannofossil zones and subzones have been recognised and correlated with planktonic (PF) and benthic (BF) foraminifera zones: transitional Santonian–Campanian CC17 or latest Santonian UC13 (Dicarinella asymetrica/D. concavata PFZone and the lower part of Globotruncanita elevata/stuartiformis PFZone), lower Campanian CC18a/UC14a, CC18b–c and CC19/UC14b–UC15a (Globotruncanita elevata/stuartiformis PFZone), lower Campanian CC20/UC15b (Contusotruncana plummerae/Globotruncana ventricosa PFZone), upper Campanian CC21/UC15c (Contusotruncana plummerae/Globotruncana ventricosa PFZone and Globotruncanella havanensis PFZone) and upper Campanian CC22/UC15d (Globotruncanella havanensis PFZone). Using magnetostratigraphic data as the primary source for definition of the base of the Campanian, we place the Santonian–Campanian boundary in the Alan-Kyr section at the level of the base of Chron C33r and inside the nannofossil transitional Santonian–Campanian CC17 or lower Campanian UC14 Zone and the planktonic foraminifera Santonian D. asymetrica/D. concavata Zone. This conclusion is supported by the relative position of other microfossil bioevents: the first occurrence of Broinsonia parca parca, which happens just above the highest occurrences of both Dicarinella asymetrica and D. concavata, as well as the lowest occurrence of the benthic foraminifera Neoflabellina asema.

中文翻译：

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钙质纳米化石和其他替代物定义了克里米亚中部山脉（Alan-Kyr 部分）的 Santonian-Campanian 边界

摘要 首次对克里米亚桑托阶和坎帕阶钙质纳米化石的分类组成和详细地层分布进行了研究。在 Alan-Kyr 部分已鉴定的钙质纳米化石组合由 85 种组成，包括所有主要和附加的带状标记。以下钙质纳米化石区和亚区已被识别并与浮游 (PF) 和底栖 (BF) 有孔虫区相关联：过渡性 Santonian-Campanian CC17 或最新的 Santonian UC13（Dicarinella asymetrica/D. concavata PFZone 和 Globotruncanita 的下部stuartiformis PFZone)、下坎帕尼亚 CC18a/UC14a、CC18b–c 和 CC19/UC14b–UC15a (Globotruncanita elevata/stuartiformis PFZone)，下坎帕尼亚 CC20/UC15b (Contusotruncana plummerae/Globotruncana ventricosa PFZone)、上坎帕尼亚 CC21/UC15c (Contusotruncana plummerae/Globotruncana ventricosa PFZone 和 Globotruncanella havanensis PFZone) 和上坎帕尼亚 CC22/UC15c (Globotruncana ventricosa PFZone)。使用磁地层数据作为定义坎帕阶底部的主要来源，我们将桑托阶 - 坎帕阶边界置于 Chron C33r 底部水平的 Alan-Kyr 剖面和纳米化石过渡桑托阶 - 坎帕阶 CC17 或更低的坎帕阶内部UC14 区和浮游有孔虫 Santonian D. asymetrica/D. 凹面区域。这一结论得到了其他微化石生物事件的相对位置的支持：Broinsonia parca parca 的首次出现，