Biogeochemical Weathering Controls on Soil Formation and Landscape Development

生物地球化学风化对土壤形成和景观发展的控制

• 批准号: 0106054
• 负责人: Jillian Banfield
• 金额: $ 26.13万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-15 至 2005-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0106054&HistoricalAwards=false
• 关键词: Biogeochemical; Weathering; Controls; Soil; Formation

AbstractBiogeochemical weathering controls on soil formation and landscape development.The soil production rate is defined as the rate at which bedrock, in this study chemically weathered granodiorite, converts to a mobile layer (soil, defined by loss of granitic texture). Previous studies have established the form of the inverse relationship between soil production rates and soil thickness. However, these studies have not compared erosion to solute losses during landscape lowering, or incorporated detailed consideration of the biogeochemical weathering processes that must precede, and generally follow, soil formation. In this project, conservation of mass equations will be solved using geochemical tracer results and existing cosmogenic dating information to determine long-term mass transfers due to erosion and solute loss during landscape development on the Bemboka Granodiorite in SE Australia. Variation in solute versus erosional fluxes with soil thickness and landscape position will be evaluated, and possible relationships between the solute loss rates (prior to soil formation), soil thickness, and microbial processes in the weathered granite will be examined. The analysis will also yield values for long-term erosion and solute losses for most elements per unit area of land surface per unit time. This investigation extends prior geomorphological approaches to incorporate biogeochemical as well as biophysical weathering contributions to soil formation and landscape evolution. Broader impacts of the research will stem from new insights into factors controlling rates of soil formation, improved understanding of the processes by which landscapes respond to perturbation, and the quantification of long-term sediment and solute fluxes to the oceans.

关于土壤形成和景观发展的抽象地球化学风化控制。土壤的生产率定义为基岩在这项研究中化学风化的花岗闪烁石的速率，转化为移动层（土壤，由花岗岩纹理损失定义）。 先前的研究已经确定了土壤生产率与土壤厚度之间的反比关系的形式。 但是，这些研究尚未将侵蚀与降低景观期间的溶质损失进行比较，也没有将详细的考虑对生物地球化学风化过程进行了详细考虑，该过程必须先于土壤形成，并且通常遵循土壤形成。在该项目中，将使用地球化学示踪剂结果和现有的宇宙源性约会信息来解决质量方程的保护，以确定澳大利亚SE澳大利亚Bemboka Granodiorite在景观开发过程中侵蚀和溶质损失引起的长期质量转移。将评估溶质与侵蚀通量的变化，并评估土壤厚度和景观位置的变化，并将检查溶质损失率（在土壤形成之前），土壤厚度和风化花岗岩中的微生物过程之间的可能关系。该分析还将在每单位时间的每单位土地面积的大多数元素中产生长期侵蚀和溶质损失的值。这项研究扩展了先前的地貌方法，以纳入对土壤形成和景观进化的生物地球化学以及生物物理风化的贡献。这项研究的更广泛的影响将源于对控制土壤形成率的因素的新见解，对景观对扰动响应的过程的理解以及对长期沉积物和溶质通量对海洋的响应的理解得到了改善。