Today's cryosphere reflects an extreme climate state that developed through stepwise global Cenozoic cooling. In this context the opening of the Fram Strait, the Atlantic-Arctic Gateway (AAG), enabled deep-water exchange between the northern North Atlantic and the Arctic Ocean and thereby influenced global ocean circulation and climate.

Here we present a new age model for Ocean Drilling Program Site 909 located in the Molloy Basin, a key site to investigate the late opening phase of the central Fram Strait and the early history of oceanic circulation in the AAG. Our results are based on a revised magnetostratigraphy calibrated by new palynomorph bioevents, which shifts previously used stratigraphies for Site 909 to significantly younger ages in the time interval from c. 15 Ma to 3 Ma. The revised late Miocene to present chronology combined with an improved core-log-seismic integration leads to a new high-resolution seismic stratigraphy for the central Fram Strait that allows a more comprehensive correlation with seismic markers from the western Barents Sea margin and also the adjacent Yermak Plateau. The new stratigraphy implies that prominent maxima in coarse sand particles and kaolinite, often interpreted as evidence for ice rafting in the Fram Strait occur at c. 10.8 Ma, c. 3 Myr later as previously inferred and thus well after the Middle Miocene Climate Transition (c. 15–13 Ma). In the late Tortonian (<7.5 Ma), sediment transport became current controlled, mainly through a western, recirculating branch of the West Spitsbergen Current. This transport was strongly enhanced between c. 6.4 and 4.6 Ma and likely linked to the subsiding Hovgaard (Hovgård) Ridge and the widening of the AAG.

Late Pliocene to Pleistocene seismic reflectors correlate with episodes of elevated ice-rafted detritus input related to major steps in Northern Hemisphere ice sheet growth such as the prominent glacial inception MIS M2 that predates the mid-Piacenzian Warm Period and the intensification of Northern Hemisphere glaciation starting at c. 2.7 Ma. At the beginning of the Mid Pleistocene Transition (c. 1.2–0.8 Ma), sediment accumulation in the Fram Strait significantly decreased.

今天的冰冻圈反映了一种极端气候状态，这种状态是通过全球新生代逐步冷却而发展起来的。在此背景下，大西洋-北极门户（AAG）弗拉姆海峡的开通，使北大西洋北部和北冰洋之间的深水交换成为可能，从而影响了全球海洋环流和气候。

在这里，我们展示了位于莫洛伊盆地的海洋钻探计划站点 909 的新时代模型，这是研究弗拉姆海峡中部开放后期和 AAG 早期海洋环流历史的关键地点。我们的结果基于由新的孢粉生物事件校准的修订磁地层学，该地层学将先前使用的 Site 909 地层学转变为在从 c.2 开始的时间间隔内显着年轻的年龄。15 毫安到 3 毫安。修订后的中新世晚期以呈现年代学，并结合改进的岩心-测井-地震整合，为弗拉姆海峡中部带来了新的高分辨率地震地层学，从而可以与巴伦支海西部边缘和邻近地区的地震标记进行更全面的关联。叶尔马克高原。新的地层学意味着粗砂颗粒和高岭石中的显着最大值，通常被解释为弗拉姆海峡冰漂流的证据发生在c。10.8 毫安，c。3 Myr 如前所述，因此在中新世气候过渡（约 15-13 Ma）之后很久。在 Tortonian 晚期（<7.5 Ma），沉积物运输成为受流控的方式，主要通过西斯匹次卑尔根洋流的西部循环分支。这种运输在c之间强烈增强。6.4 和 4.6 Ma，可能与下沉的 Hovgaard (Hovgård) Ridge 和 AAG 的扩大有关。泥沙运输主要通过西斯匹次卑尔根洋流的西部循环支流受到水流控制。这种运输在c之间强烈增强。6.4 和 4.6 Ma，可能与下沉的 Hovgaard (Hovgård) Ridge 和 AAG 的扩大有关。泥沙运输主要通过西斯匹次卑尔根洋流的西部循环支流受到水流控制。这种运输在c之间强烈增强。6.4 和 4.6 Ma，可能与下沉的 Hovgaard (Hovgård) Ridge 和 AAG 的扩大有关。

晚上新世至更新世地震反射器与与北半球冰盖生长的主要步骤相关的升高的冰筏碎屑输入事件相关，例如在皮亚琴世中期暖期中期出现的显着冰川开始 MIS M2 和北半球冰川开始的加剧在 c。2.7 毫安。在中更新世过渡初期（c. 1.2-0.8 Ma），弗拉姆海峡的沉积物积累显着减少。