Miocene vegetation dynamics at the New Jersey Atlantic margin

该项目的总体目标是通过对孢粉记录的高分辨率分析，识别和量化新泽西浅海陆架腹地在中新世气候最佳期之前(约17.8 Ma BP)、期间(约15.7 Ma BP)和之后(约13.5 Ma BP)的植被和气候变化。此外，应使用来自相同样本的海洋孢粉组合(特别是甲藻孢囊)来确定海洋领域的温度和盐度变化。选定的三个时段反映了中新世中期不同的气候条件：气温和大气二氧化碳值上升、升高和迅速下降。在时间分辨率为1至3ka的情况下，应当能够识别和详细分析冷却事件(例如Mi事件)以及探测轨道诱导的循环。主要的工作假设是，新泽西大西洋边缘腹地的植被和区域气候发展仅部分反映了中新世全球气候变化，区域特征导致了对中新世气候最佳的冲淡响应。陆地领域的定量降水和温度数据将通过对花粉组合应用最近生活亲缘关系方法来生成，并与根据甲藻孢囊和其他海洋代用品对海洋条件的定性估计进行比较。这种方法将允许检测陆地和海洋信号的去耦合阶段。研究结果还将与当地和全球构造事件以及海平面和气候变化进行比较，使用在IODP Expesion313框架内建立的可靠的年龄模型。新泽西州浅海陆架沉积速率高，时间分辨率高，孢粉形态保存良好，构造稳定，非常适合进行这类研究。

The overall goals of this project are the identification and quantification of vegetation and climate changes in the hinterland of the New Jersey shallow shelf for three intervals preceding, (around ~17.8 ma BP), during (around ~15.7 ma BP), and after the Miocene climatic optimum (around ~13.5 ma BP) via high-resolution analyses of pollen records. In addition, marine palynomorph assemblages (particularly dinoflagellate cysts) from identical samples shall be used to identify temperature and salinity changes in the marine realm. The three selected intervals reflect different climatic conditions during the middle Miocene: increasing, high, and rapidly decreasing temperatures and atmospheric carbon dioxide values. With temporal resolutions of 1 to 3 ka, the identification and detailed analysis of cooling events (e.g., Mi-events) should be possible as well as the detection of orbitally-induced cycles. The main working hypothesis is that the vegetation and regional climate development in the hinterland of the New Jersey Atlantic margin only partly reflected global climate change during the middle Miocene, and that regional peculiarities caused a diluted response to the Miocene climatic optimum. Quantitative precipitation and temperature data for the terrestrial realm will be generated via the application of the nearest-living-relative method to the pollen assemblages, and compared to qualitative estimates of marine conditions based on dinoflagellate cysts and additional marine proxies. This approach will allow detecting phases of decoupling of terrestrial and marine signals. The results will furthermore be compared with local and global tectonic events and sea level- and climate changes using the robust age models established in the framework of IODP Expedition 313. The New Jersey shallow shelf is well-suited for this kind of examination due to high sedimentation rates, guaranteeing high temporal resolution and good palynomorph preservation, and due to tectonic stability.