(GRGC) Isotope Sedimentology of 40ka Time-Series From Iberian Sites as a Test of Abrupt Arid/Himid Switching Within the Mediterranean Climate Zone

在比较高纬度地区事件的结构和时间方面，西地中海过去40ka的古气候仍然存在争议。该建议的目标是在伊比利亚半岛东部的3个地点开发高分辨率的沉积物和同位素地层学。其目标是朝着一个时间序列的方法来测试突变的潮湿/干旱过渡的一致性，包括海因里希事件或Dansgaard-Oschger周期对欧洲和非洲之间区域过渡的潜在湿度影响。该项目是一个独特的合作机会，来自巴塞罗那的西班牙同事将提供支持古生态分析和获得高质量，长，连续的湖泊岩心。这些岩心有足够的年代证明它们包含距今40ka年前的记录。这三个地点：La Paul de Bubal（比利牛斯山脉中部），北部的Banyoles湖（比利牛斯山脉东部）和西班牙东南部的Salines湖，形成了横跨湿度梯度的样带。每个岩心都含有丰富的、良好的自生和生物成因碳酸盐相，忠实地记录了过去水动力学的同位素特征。研究结果将在气候模式变化的背景下进行解释，气候模式的变化决定了有效湿度。该项目还将测试解释碳和氧同位素比率的新策略。由于解释动态大陆地区稳定同位素的固有困难，该项目依赖于几种代用指标（沉积物、地球化学、磁性、同位素和花粉）以及微尺度相分析和样品表征的仔细整合。补充AMS放射性碳和Th/U定年将用于提高事件转换的精度。

9418657 Kelts The western Mediterranean paleoclimate during the last 40ka remains controversial in terms of comparing structure and timing of events with higher latitudes. This proposal targets the development of high resolution sediment and isotope stratigraphies from 3 sites of the eastern Iberian peninsula. Its objectives are to move toward a time-series approach to testing for the coherency of abrupt humid/arid transitions including potential moisture impacts from Heinrich events or Dansgaard-Oschger cycles over a region transitional between Europe and Africa. The project is a unique collaborative opportunity with Spanish colleagues from Barcelona who will provide supporting paleoecological analyses and the access to high-quality, long, continuous lacustrine cores. These cores have adequate dating to prove they contain records back 40ka BP. These 3 sites: La Paul de Bubal (central Pyrenees), Lake Banyoles (eastern Pyrenees) in the north and Lake Salines in southeast Spain, form a transect across moisture gradients. Each core contains abundant, good authigenic and biogenic carbonate phases which faithfully archive isotope signatures of the past aqueous dynamics. The results will be interpreted within the context of changing climatic patterns which determine effective moisture. The project will also test new strategies for the interpretation of carbon and oxygen isotopic ratios. Because of the inherent difficulties of interpreting stable isotopes from dynamic continental areas, this project depends on the careful integration of several proxies (sediment, Geochemical, magnetic, isotope and pollen) as well micro-scale facies analyses and sample characterization. Supplementary AMS radiocarbon and Th/U dating will be applied to increase precision across event transitions.