Abstract

Forty-seven rock samples from the stratotypes of three upper Paleogene formations – Prussian, Palvé, and Kurshskaya formations – were collected from the biggest amber deposit worldwide (Primorsky quarry, Kaliningrad Oblast SE Baltic coast), and have been palynologically analyzed. The presence of age-diagnostic dinoflagellate cyst species has allowed us to refine and update the previously questionable age of regional lithostratigraphical units. Based on the presence of Rhombodinium perforatum, the ‘Upper Wild Earth’ and ‘Upper Blue Earth’ members of the Prussian Formation correspond to the early Priabonian (Late Eocene) Rhombodinium perforatum Zone. The overlying ‘Upper Quicksand’ and ‘White Wall’ members of the Prussian Formation contain the key-species Thalassiphora reticulata, and are correlated with the latest Priabonian T. reticulata Zone. The overlying Palvé Fm (‘Green Wall’), comprises a dinoflagellate cyst assemblage very close to that recorded from the Prussian Formation, and also corresponds to the T. reticulata Zone, late Priabonian. The lower part of the Kurshskaya Formation – ‘Chocolate clays’ and lower ‘Brown sands’ members, contain an impoverished dinoflagellate cyst assemblages as a result of significant environmental changes. However, the common presence of Areosphaeridium diktyoplokum and Glaphyrocysta semitecta, along with an absence of early Oligocene key-species Wetzeliella gochtii or Chiropteridium galea, and pollen key-species Boehlensipollis hohli or Aglaoreidia cyclops, suggest the lower Kurshskaya Formation can be correlated with the uppermost Eocene, and very close to the Eocene/Oligocene boundary. Based on the revised stratigraphical ages presented here, we suggest an important regional marine transgression occurred during the Priabonian, which allowed the direct marine connection between the NW European Basin and Peri-Tethys via the Polish-Luthuanian Seaway. This was then followed by a regression at the end of Priabonian that culminated in a transition to continental sedimentation in the early Rupelian. A new dinoflagellate cyst species Oligokolpoma balticus sp. nov. is formally described.

摘要

从全球最大的琥珀矿床（滨海边疆区采石场、加里​​宁格勒州东南波罗的海沿岸）收集了来自三个上古近纪地层——普鲁士地层、帕尔韦地层和库尔什卡亚地层——层型的 47 个岩石样本，并进行了孢粉学分析。年龄诊断甲藻囊肿物种的存在使我们能够改进和更新以前有问题的区域岩石地层单位的年龄。基于Rhombodinium perforatum的存在，普鲁士组的'Upper Wild Earth' 和'Upper Blue Earth' 成员对应于早期的Priabonian（晚始新世）Rhombodinium perforatum带。普鲁士组上覆的“上流沙”和“白墙”成员包含关键物种Thalassiphora reticulata，并与最新的 Priabonian T. reticulata带相关。上覆的Palvé Fm（'绿墙'），包括一个非常接近于普鲁士组记录的甲藻包囊组合，并且也对应于普里雅波世晚期的T. reticulata带。Kurshskaya 组的下部——“巧克力粘土”和较低的“棕砂”成员，由于环境的显着变化，含有贫化的甲藻囊组合。然而，Areosphaeridium diktyoplokum和Glaphyrocysta semitecta的共同存在，以及早期渐新世关键物种Wetzeliella gochtii或Chiropteridium galea的缺失, 和花粉关键种Boehlensipollis hohli或Aglaoreidia cyclops , 表明下部 Kurshskaya 组可以与最上部的始新世相关联, 并且非常接近始新世/渐新世边界。根据这里提出的修正地层年龄，我们认为在普里雅本期发生了一次重要的区域海侵，这使得西北欧洲盆地和 Peri-Tethys 之间通过波兰-卢陶宛海道直接建立了海洋联系。紧随其后的是普里雅波世末期的回归，最终在鲁佩期早期向大陆沉积过渡。一种新的甲藻囊肿种Oligokolpoma balticus sp。十一月 被正式描述。