Evolution of Geochemical Processes in Soils on Elevated Marine Terraces in Coastal Oregon

俄勒冈州布兰科角附近的高架海洋梯田的航班， 土壤的年代顺序包括，从最年轻到最古老， 灰化土、灰化土、双等土（灰化土/淋溶土），以及 终极土壤 该项目的目标是确定 地球化学过程的影响 的定量变化 随着时间的推移，土壤成分将从地球化学 质量平衡法和粒度测量 分布、堆密度、可提取的Fe、Al、Si和C， 交换性盐基、交换性酸度和全元素分析（NAA XFA）。 热力学稳定性指数将由 土壤矿物学数据（岩相学和XDA）和水溶液- 化学数据（pH、氧化还原电位、Fe、Al、Si、DOC、DIC散装 收集的降水、林冠穿透降水和土壤溶液） GEOCHEM化学平衡模型。 地球化学物质 平衡和建模将用于测试假设， 母质的来源（风成沉积与风化 海滩沉积物。 土壤的形成过程将从 上述数据和微观分析（土壤 微形态和扫描电镜）的诊断土壤特征（黑色素 epipedons、placic和ortstein层和粘质层）。

Flights of elevated marine terraces near Cape Blanco, Oregon, have soil chronosequences that include, from youngest to oldest, Andisols, Spodosols, bisequal soils (Spodosols/Ultisols), and Ultisols. The goal of the project is to determine the evolution of geochemical processes in these soils. Quantitative changes in soil constituents over time will be determined from the geochemical mass-balance approach and measurements of particle-size distribution, bulk density, extractable Fe, Al, Si, and C, exchangeable bases and acidity, and total elemental analysis (NAA and XFA). Thermodynamic stability indices will be estimated from soil mineralogical data (petrography and XDA) and aqueous solution- chemistry data (pH, redox potential, Fe, Al, Si, DOC, DIC in bulk precipitation, canopy throughfall, and soil solutions collected) using the GEOCHEM chemical-equilibrium model. The geochemical mass balances and modeling will be used to test hypotheses regarding the origin of the parent materials (aeolian deposition vs. weathering of beach sediments. Soil-forming processes will be elucidated from the forementioned data and microscopic analyses (soil micromorphology and SEM) of diagnostic soil features (melanic epipedons, placic and ortstein horizons, and argillic horizons).