Gas-IRMS for high-precision analysis of Δ17O with sample preparation line

PI的最新工作突出了16O-17O-18O系统在过去和现在的定量同位素水文学领域的新应用领域。在目前的项目中，我们首先将建立一条将碳酸盐结合氧转化为纯氧气的半自动制备线，这是以足够精度分析Delta 17O所需的。通过应用于Gas-IRMS，我们寻求系统地研究来自土壤、地下水含水层和地球表面其他水库的蒸发。这些研究的目的是量化干旱和半干旱环境的水平衡。这包括确定随季节变化的水源和当地蒸发水回收利用。在一项初步研究中，我们还试图应用该方法来量化抗旱植物的水分平衡。然后，这些系统研究的结果将被用于量化过去的蒸发和重建水文气候循环的变化，其基础是对成壤碳酸盐(来自纳米比亚的钙石)、湖相石膏(西班牙的Fuente de Piedro湖)和湖相碳酸盐(土耳其的凡湖)的地质样品进行Delta 17O分析。在与共同申请者的其他项目中，我们寻求将经典的H、C、N和O同位素分析应用于古海洋学和史前考古领域。在前两项研究中，目的是重建地中海和大西洋之间水团交换的过去变异性及其在大西洋温盐环流中的作用。这项工作的一个重要部分是开发改进的替代工具，用于重建沿大陆斜坡的等高线水流和重建深水通风。这些工具以海底有孔虫贝壳的碳和氧同位素分析为基础，并结合微量元素分析。在史前考古领域，有两个主要目标。通过使用木材中的氢、碳和氧同位素分析-部分由广泛的科隆树状档案馆提供-我们试图重建中欧全新世的年度分辨率过去的气候和环境变异性。通过将这些发现与骨骼中的碳、氮同位素分析相结合，我们试图找出新石器时代晚期居民流动模式的演变和农业实践的变化。另一个主要目标涉及旧石器时代的营养水平和食物资源的演变，在旧石器时代，我们首先寻求从巴伐利亚州塞塞尔费尔斯格罗特沉积长序列中发现的大量动物骨骼建立跨越90至40ka BP各种气候振荡的同位素基线。在另一项研究中，目标是通过对中欧一些年代较晚的更新世狩猎营地发现的骨骼进行同位素分析，得出被猎杀动物的活动情况，特别是驯鹿和马。

The most recent work of the PI has highlighted novel fields of application for the System of 16O - 17O - 18O in the field of quantitative isotope hydrology of the past and present. In the current project, at first we will build a semi-automated preparation line to convert carbonate-bound oxygen to pure oxygen gas, which is required for the analysis of Delta 17O at sufficient precision. With the applied-for Gas-IRMS we seek to systematically investigate evaporation from soil, from ground water aquifers, and other water reservoirs of the Earth’s surface. The aim of these studies is to quantify the water budget of arid and semi-arid environments. This includes the identification of seasonally varying water sources and local evaporative water recycling. In a pilot study we also seek to apply the method to quantify the water budget of drought-resistant plants. Results from theses systematic studies will then be applied to quantify past evaporation and reconstruct changes in the hydroclimatic cycle, based on Delta 17O analysis in geologic samples of pedogenic carbonate (calcretes from Namibia), lacustrine gypsum (Laguna de Fuente de Piedro, Spain), and lacustrine carbonate (Lake Van, Turkey). In additional projects with co-applicants, we seek to apply classical H, C, N, and O isotope analysis in the fields of paleoceanography and prehistoric archaeology. In the first of the two, the aim is to reconstruct past variability of exchange of water masses between the Mediterranean and the Atlantic and its role in Atlantic thermohaline circulation. A significant part of this undertaking is the development of enhanced proxy-tools for reconstructing contour currents along the continental slope and for reconstructing deep-water ventilation. These tools are based on C and O isotope analysis of benthic foraminifera shells in combination with trace element analysis. In the field of prehistoric archaeology there are two major objectives. By using H, C, and O isotope analysis in wood - partly supplied by the extensive Cologne Dendro-Archive - we seek to reconstruct past climate and environmental variability with annual resolution for the Holocene of central Europe. By combining these findings with C and N isotope analysis from bones, we seek to work out the evolution of residential mobility patterns and changing agricultural practices in the late Neolithic. The other main objective concerns trophic levels and evolution of food resources in the paleolithic, where we first seek to establish the isotopic baseline across various climate oscillations between 90 and 40 ka BP from the numerous animal bones found in the long sequence of deposits from Sesselfelsgrotte, Bavaria. In another study, the objective is to derive movements of hunted animals - in particular reindeer and horse - from isotope analysis of bones found at a number of well-dated hunter camp sites of late pleistocene age across central Europe.