Quantitative analysis of assemblage similarity among chitinozoan and acritarch associations recovered from various sedimentary sequences across the Trans European Suture Zone (TESZ; southern Baltic Sea and northern Germany region), permits evaluation of changes in microplankton palaeobiogeography during the Ordovician in the study area. The present data confirm strong palaeobiogeographic differences between the lower Ordovician of the Rügen area, and the coeval domains of the East European Platform (EEP), corroborating the idea that the subsurface of Rügen should be considered palaeogeographically as the eastern extension of Avalonia.Cluster analysis of chitinozoan assemblages from numerous wells in the Rügen area, and one well from the southern margin of the EEP indicates that chitinozoan bioprovincialism reached its maximum during the Llanvirn; during this period, the Rügen microplankton communities were clearly Gondwanan in character. Calculations using the coefficient of similarity support the conclusion of a high similarity between Llanvirn acritarch assemblages from the Rügen subsurface and from coeval Perigondwana localities (e.g. Tunisia). Since the early Caradoc, this Gondwanan affinity of the Rügen microfossils starts to lessen, and becomes negligible during the late Caradoc. During latest Caradoc-early Ashgill through Llandovery times the chitinozoan assemblages from either side of the TESZ are undistinguishable. If palaeobiogeographical differentiation is primarily related to palaeolatitudinal distance, then the present data support closure of the Tornquist Ocean during late Caradoc-Ashgill times. The presence of reworked Llanvirn acritarchs of Perigondwanan affinity in middle Ashgill sedimentary sequences at the southern margin of the EEP, clearly shows that by this time erosion of an uplifted area was taking place. Accordingly, the closure of the Tornquist Ocean, and consequent Avalonia-Baltica collision must have taken place during the time interval between the middle Caradoc and the early middle Ashgill (Rawtheyan).New chitinozoan data from boreholes H 2 and K 5, offshore of Rügen Island, northern Germany, allow for precise biostratigraphic dating. In the pre-Devonian part of H 2, Siphonochitina formosa indicates an Abereiddian (Early Llanvirn) age, facilitating correlation with boreholes Binz 1/73 and Lohme 2/70 of Rügen. In borehole K 5, the occurrence of Belonechitina robusta and Tanuchitina bergstroemi permits attribution of the investigated pre-Carboniferous sequence to the middle-late Caradoc, and, possibly, early Ashgill.

中文翻译：

---

跨欧洲缝合带北部奥陶纪-早志留纪微浮游生物古生物地理学的定量评价：对阿瓦隆尼亚-波罗的海碰撞时间的影响

对从跨欧洲缝合带（TESZ；波罗的海南部和德国北部地区）的各种沉积序列中恢复的几丁质动物和 acritarch 协会之间的组合相似性进行定量分析，可以评估研究区奥陶纪期间微型浮游生物古生物地理学的变化。目前的数据证实了吕根岛地区下奥陶统与东欧地台 (EEP) 的同时代区域之间存在强烈的古生物地理差异，证实了吕根岛的地下应在古地理上被视为阿瓦隆尼亚东部延伸的观点。 聚类分析Rügen 地区多口井和 EEP 南缘一口井的几丁质动物组合表明，在 Llanvirn 期间，几丁质动物的生物省力达到了最大值；在此期间，吕根岛微型浮游生物群落具有明显的冈瓦纳特征。使用相似系数的计算支持了来自吕根岛地下的 Llanvirn acritarch 组合与来自同时代的 Perigondwana 地区（例如突尼斯）的高度相似性的结论。从早期的卡拉多克开始，吕根岛微化石的冈瓦纳亲和力开始减弱，在卡拉多克晚期变得可以忽略不计。在最近的 Caradoc 早期 Ashgill 到 Llandovery 时期，来自 TESZ 两侧的几丁质动物组合无法区分。如果古生物地理分化主要与古纬度距离有关，那么目前的数据支持在 Caradoc-Ashgill 时代晚期 Tornquist 洋的闭合。在 EEP 南缘的中间 Ashgill 沉积层序中，重新加工的具有 Perigondwanan 亲和性的 Llanvirn acritarchs 的存在清楚地表明，此时隆起区域正在发生侵蚀。因此，Tornquist 洋的闭合以及随后的 Avalonia-Baltica 碰撞一定发生在 Caradoc 中部和 Ashgill 中部早期 (Rawtheyan) 之间的时间间隔内。 来自吕根岛近海钻孔 H 2 和 K 5 的新几丁质动物数据德国北部的岛屿允许进行精确的生物地层测年。在 H 2 的前泥盆纪部分，Siphonochitina formosa 表明 Abereiddian (Early Llanvirn) 时代，促进了与吕根岛 Binz 1/73 和 Lohme 2/70 钻孔的相关性。在钻孔 K 5 中，