Climatic indications from soils and sands, and their lithified equivalents

沉积物是了解地球气候条件随时间和空间变化的重要资源。具体的大气指标由以下各项表示：1）土壤风化剖面; 2）重矿物组（密度>2.9的矿物）的分布; 3）稳定碎屑矿物（如石英）的比例;以及4）对风化高度敏感的铝硅酸盐（粘土）矿物。砂和砂岩特别有利于成分研究（即矿物和岩石碎片），而细粒级分则可用于主量和微量元素地球化学以及稳定同位素分析。这项拟议的研究计划的目的是双重的，涉及，i）确定在地球历史的特定时期沉积物形成和沉积的气候条件，以及ii）研究现代环境中不同的气候条件如何控制沉积物成分。这项研究计划代表了项目和分析技术的整合，将有助于更清楚地了解地球的气候演变。拟议的项目如下：（1）加拿大西部沉积盆地晚阿尔布期“正常”和“超级”古土壤的区别及其对气候条件和海侵的影响;（2）新西兰奥塔哥中部地区晚白垩世-中新世的气候变化，从多种古土壤中得到证明;（3）玄武岩上发育的现代含岩芯土壤剖面中微量元素的分布;气候对纳米比亚和新西兰现代干旱和温带冲积扇沉积物成分和结构的影响。将使用主要和微量元素地球化学和稳定同位素分析、扫描电子显微镜和阴极发光光谱法分析样品。该研究计划将资助两名博士。学生，两名硕士生和一名博士后研究员。该研究计划意义重大，因为在地球演变方面，控制沉积物组成的最重要过程是气候，因为它直接影响我们星球上生物群的发展。

Sedimentary deposits are a significant resource for understanding Earth's changing climatic conditions through time and space. Specific atmospheric indicators are represented by 1) soil weathering profiles 2) the distribution of heavy mineral suites (minerals with densities >2.9), 3) proportions of stable detrital minerals, such as quartz, and 4) aluminosilicate (clay) minerals that are highly sensitive to weathering. Sands and sandstones are particularly favourable for componentry studies (i.e. minerals and rock fragments), whereas finer-grained fractions are useful for major and trace element geochemistry, and stable isotope analysis. The aim of this proposed research program is two-fold and involves, i) determining the climatic conditions that governed sediment formation and deposition at specific times in Earth history, and ii) examining how different climatic conditions in modern settings control sediment composition. This research program represents a consolidation of projects and analytical techniques that will contribute toward a clearer understanding of Earth's climatic evolution. The following projects are proposed: i) Distinguishing between Late Albian "normal" and "super" palesols in the Western Canada Sedimentary Basin, and their implications for climate conditions and marine transgression, ii) Climatic variations during the Late Cretaceous-Miocene Central Otago region, New Zealand as evidenced from multiple paleosols, iii) The distribution of trace elements in modern corestone-bearing soil profiles developed on basalt, and iv) The effects of climate on the composition and textures of modern arid and temperate alluvial fan deposits of Namibia and New Zealand. The samples will be analyzed using major and trace element geochemistry and stable isotope analysis, scanning electron microscopy, and cathodoluminescence spectroscopy. The proposed research program will fund two Ph.D. students, two M.Sc. students and one Post-doctoral Fellow. The research program is significant because the most important process governing sediment composition with respect to Earth's evolution is climate, as it directly affects the development of biota on our planet.