Middle Miocene (Serravallian; upper Badenian–lower Sarmatian) dinoflagellate cysts from Bad Deutsch-Altenburg, Vienna Basin, Austria

Middle Miocene (Serravallian; upper Badenian–lower Sarmatian) strata recovered in 10 cored boreholes (83 samples) from Bad Deutsch-Altenburg, Vienna Basin, Austria, were analysed palynologically for the first time. The strata belong to the Rabensburg Formation of the Baden Group. The lateral distribution of the boreholes in reference to a Mesozoic ridge makes this area interesting for studying various aspects such as distribution of deposits, stratigraphy and palaeoenvironmental reconstruction. A diverse and well-preserved in situ dinoflagellate cyst association has been identified. Middle Miocene age-diagnostic species including Cannosphaeropsis passio, Cerebrocysta poulsenii, Habibacysta tectata, Labyrinthodinium truncatum, Operculodinium? borgerholtense and Unipontidinium aquaeductum are recorded. Their occurrences allow correlation with dinoflagellate cyst biozonations on a regional scale. Based on the identified dinoflagellate cysts and by correlation with calcareous nannoplankton and ostracods, from the same set of samples, a Serravallian age – corresponding to a late Badenian and early Sarmatian age (regional Paratethys stages) – is confirmed. Reworked (Cretaceous and Paleogene) dinoflagellate cyst assemblages, also well preserved, were recorded abundantly from boreholes HA 521 and HA 573 (south-west of the Mesozoic ridge). In accordance with ostracods, the Badenian–Sarmatian boundary can be traced in the upper part of borehole HA 66 based on an abrupt change in the dinoflagellate cyst assemblages. The upper Badenian strata were deposited in a coastal to inner shelf environment with terrigenous (siliceous sand and clay) and carbonate sediments. The recorded dinoflagellate cysts reflect marine, tropical to warm-temperate climatic conditions. The composition of the recorded dinoflagellate cyst assemblages is very close to that of the Middle Miocene assemblages of the Mediterranean, indicating water exchanges between the Central Paratethys and the Mediterranean during the late Badenian (early Serravallian).

首次对奥地利维也纳盆地巴德多伊奇阿尔滕堡地区10个取心钻孔（共83件样品）获取的中中新世（塞拉瓦尔阶；上巴登阶-下萨尔马提亚阶）地层开展了孢粉学分析。该地层隶属于巴登群拉本斯堡组。钻孔相对于中生代隆起的横向分布特征，使得该区域在沉积分布、地层学及古环境重建等诸多方面的研究中具有重要价值。研究人员已识别出一套多样且保存完好的原地沟鞭藻囊孢（dinoflagellate cyst）组合。本次研究记录了多个具有中中新世时代指示意义的物种，包括*Cannosphaeropsis passio*、*Cerebrocysta poulsenii*、*Habibacysta tectata*、*Labyrinthodinium truncatum*、*Operculodinium? borgerholtense*及*Unipontidinium aquaeductum*。这些物种的产出特征可用于区域尺度上的沟鞭藻囊孢生物地层带对比。基于本次识别出的沟鞭藻囊孢，并结合同批次样品中的钙质超微浮游生物（calcareous nannoplankton）与介形类（ostracods）化石进行对比分析，本次研究证实了该地层的塞拉瓦尔阶时代归属，其对应晚巴登阶及早萨尔马提亚阶（区域副特提斯（Paratethys）沉积阶）。在中生代隆起西南侧的HA 521与HA 573钻孔中，还大量产出了保存完好的再沉积（白垩纪及古近纪）沟鞭藻囊孢组合。结合介形类化石特征，基于沟鞭藻囊孢组合的突变特征，可在HA 66钻孔的上部地层中识别巴登阶-萨尔马提亚阶界线。上巴登阶地层形成于海岸至内陆棚环境，沉积物质包括陆源碎屑（硅质砂与黏土）及碳酸盐沉积物。本次记录的沟鞭藻囊孢指示了海洋环境下的热带至暖温带气候条件。本次记录的沟鞭藻囊孢组合组成与地中海地区中中新世组合极为相似，表明晚巴登阶（早塞拉瓦尔阶）期间，中副特提斯与地中海之间存在水体交换。