Abstract Calcareous nannofossils of the Serravallian/Tortonian transition, known as the Sarmatian in the Paratethys were obtained from the northern Croatia, Central Paratethys. The nannofossil biostratigraphy of the studied area included early Sarmatian biohorizons; the reliability of these and previous biohorizons was tested, and the known biostratigraphic and magnetostratigraphic datums of the Paratethys were compared with those from the adjacent Mediterranean and beyond. Six out of sixteen bioevents were selected to define five subzones (PNN6d-PNN8b) and crossover for the Badenian/Sarmatian boundary. Variations in the index fossil datums between the Paratethys and Tethys provide a broad perspective on local versus regional and global impacts on the nannofloras. The Paratethys/Tethys gateways (PTGs), and their progressive geodynamical closure, exerted a fundamental control on the salinity, circulation patterns and climate of the area. The global regression at the end of the Badenian, and the tectonic events associated with the Badenian/Sarmatian transition, also restricted the PTGs, initiating acmes of Calcidiscus pataecus and Reticulofenestra pseudoumbilicus, causing a small, early Sarmatian extinction event that occurred in coastal environments, which are the most affected by short-term environmental fluctuations. Stronger connections through the PTGs during the early/mid-Sarmatian transition induced a transgression that brought deep-dwelling Discoaster species into the area. The final closure of the PTG with the Mediterranean, which had been placed at the Badenian/Sarmatian boundary, actually occurred in the late Sarmatian as a result of tectonic movements that caused shallowing and a drastic reduction in nannofossil biodiversity. The PTG with the Indian Ocean existed until the early Tortonian, which allowed an early, but brief, occurrence of small, warm-water ceratoliths.

中文翻译：

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基于钙质纳米化石的克罗地亚北部边缘海的萨尔马提亚生物地层学

摘要 Serravallian/Tortonian 过渡的钙质纳米化石，被称为Paratethys 中的Sarmatian，是从克罗地亚北部中部Paratethys 获得的。研究区域的纳米化石生物地层包括早期萨尔马提亚生物地层；对这些和以前的生物地层的可靠性进行了测试，并将帕拉提提斯已知的生物地层和磁地层数据与邻近地中海及其他地区的数据进行了比较。选择十六个生物事件中的六个来定义巴登/萨尔马提亚边界的五个亚区 (PNN6d-PNN8b) 和交叉。Paratethys 和 Tethys 之间索引化石数据的变化提供了一个广阔的视角，可以了解本地与区域和全球对纳米植物群的影响。Paratethys/Tethys 通道 (PTG) 及其渐进的地球动力学关闭，从根本上控制了该地区的盐度、环流模式和气候。Badenian 末期的全球回归以及与 Badenian/Sarmatian 过渡相关的构造事件也限制了 PTG，引发了 Calcidiscus pataecus 和 Reticulofenestra pseudoumbilicus 的顶点，导致了在沿海环境中发生的小型早期萨尔马特灭绝事件，受短期环境波动的影响最大。在萨尔马提亚早期/中期过渡期间，通过 PTG 的更强连接引发了海侵，将深居的 Discoaster 物种带入了该地区。位于巴登尼亚/萨尔马提亚边界的 PTG 与地中海的最终关闭，由于构造运动导致纳米化石生物多样性变浅和急剧减少，实际上发生在萨尔马提亚晚期。印度洋的 PTG 一直存在到托尔托阶早期，这使得小型温水角岩早期但短暂的出现。