Collaborative Research: Unraveling the post-Pliocene Arctic Ocean transition to the icehouse climate

提供了资金，使私营部门能够根据北冰洋西部的沉积岩心，连续记录北冰洋在早至中更新世气候变冷和冰盖增长的情况下发生的变化。他们将利用一套替代指标(微型动物群组合、稳定和放射性同位素、生物标志物、沉积物矿物学以及元素组成和粒度)来重建冰川输入、海冰和水循环的变化。与北冰洋的其他岩心不同，一个独特的沉积岩芯具有丰富的钙质微化石记录，贯穿第四纪大部分地区，并可能延伸到上新世，这将极大地促进古生物和地球化学指标的使用。这是一个他们可以利用的独特发现，因为北极岩芯通常只在第四纪晚期沉积物中保存钙质微化石。年龄控制将通过古地磁、10Be、锶同位素和旋回地层学方法实现。这项研究将使他们能够测试是否存在冰盖和海冰覆盖的整体渐进增长，以及海冰和大陆冰川是否同步变化。他们还将通过分析来自Laurentide北部边缘的冰川输入的变化来测试中更新世的转变是否导致了超厚的Laurentide冰盖的增长，该冰川的门槛冰川记录约为650ka，开启了冰库世界。

Funds are provided to allow the PIs to develop a continuous record of changes in the Arctic Ocean in response to climatic cooling and growth of ice sheets in the Early to Middle Pleistocene based on sediment cores from the western Arctic Ocean. They will utilize a suite of proxies (microfaunal assemblages, stable and radiogenic isotopes, biomarkers, sediment mineralogy and elemental composition and grain size) to reconstruct variations in glacial inputs, sea ice, and water circulation. The use of paleobiological and geochemical proxies will be greatly enhanced by a unique sediment core that has a rich calcareous microfossil record extending through most of the Quaternary and potentially into the Pliocene, unlike other cores from the Arctic Ocean. This is a unique find that they can capitalize on as Arctic cores typically preserve calcareous microfossils only in Late Quaternary sediments. Age control will be achieved by paleomagnetic, 10Be, Sr-isotope, and cyclostratigraphic methods. This research will allow them to test whether there was an overall progressive growth in ice sheets and sea-ice cover and if sea ice and continental glaciers changed synchronously. They will also test whether the Mid Pleistocene Transition led to the growth of a super-thick Laurentide Ice Sheet by analyzing changes in glacial inputs from the northern Laurentide margin, with a multi-century scale record for the threshold glaciation ca. 650 ka, which initiated the icehouse world.