Miocene vegetation dynamics at the New Jersey Atlantic margin

该项目的总体目标是通过对花粉记录的高分辨率分析，识别和量化新泽西浅水陆棚腹地在中新世气候最佳期（约13.5 ma BP）之前（约17.8 ma BP）、期间（约15.7 ma BP）和之后（约17.8 ma BP）三个时间段的植被和气候变化。此外，来自相同样品的海洋孢粉组合（特别是甲藻孢囊）应用于确定海洋领域的温度和盐度变化。这三个选定的时间段反映了中新世中期不同的气候条件：温度和大气二氧化碳值的上升、升高和迅速下降。在1 ~ 3 ka的时间分辨率下，MI事件）以及轨道诱导周期的检测应该是可能的。主要的工作假设是，植被和区域气候发展的腹地的新泽西大西洋边缘只有部分反映了全球气候变化在中新世中期，和区域的特殊性导致稀释响应中新世气候最佳。定量降水和温度数据的陆地领域将产生通过应用最近的生活相对的方法的花粉组合，并进行比较，以定性估计的海洋条件的基础上甲藻孢囊和其他海洋代理。这种方法将允许检测陆地和海洋信号的解耦阶段。此外，还将使用在IODP第313次考察框架内建立的可靠年龄模型，将结果与当地和全球构造事件以及海平面和气候变化进行比较。新泽西浅海陆棚非常适合进行这种检查，因为它具有高沉积速率，保证了高时间分辨率和良好的孢粉保存，而且由于构造稳定性。

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.