Kinetics of Dissolution and Crystal Growth of Silicates and Aluminosilicates in Aqueous Soultions at Low Temperatures

拉萨加9526794 建议继续研究硅酸盐和铝硅酸盐的溶解和沉淀动力学的实验测定，作为pH值、温度、离子强度、催化/抑制和反应吉布斯自由能的函数。 我们将使用表面分析技术（XPS，AES，SEM，AFM，特别是）检查反应矿物的表面，当结合使用流通和柱反应器从溶液shemetry确定的速率时，将提供表面反应机制的信息。 利用原子力显微镜在较低温度下对反应矿物表面进行原位观测，并在热液温度下采用新的光学干涉技术，将为传统的动力学实验和非原位表面分析提供一座桥梁。 矿物-流体相互作用动力学的新实验结果将与我们小组进行的广泛分子物理研究相结合，以确定控制地球化学过程的原子动力学。 我们的实验工作继续领先于描述主要成岩硅酸盐和铝硅酸盐的溶解和沉淀速率作为G的函数，以及第一个测量沉淀速率的阶段比石英更复杂。 在我们先前的工作中开发的非平凡的全速率定律被证明是非常重要的，成功地将实验速率数据应用于模型现场的情况下，如Pijiguaos，铝土矿存款在委内瑞拉使用精确的二维流体动力学流体流动模型。 随着这里提出的持续工作，实验，理论和模型的耦合将导致第一个完全定量的物理和化学模型的水-岩石相互作用，从原子水平的现场设置下的一系列地质环境，包括成岩作用在一个动态的沉积盆地或化学演化的主要铝土矿存款。

Lasaga 9526794 It is proposed to continue the studies of the experimental determination of the dissolution and precipitation kinetics of silicates and aluminosilicates as functions of pH, temperature, ionic strength, catalysis/inhibition and the Gibbs Free energy of reaction. We will examine the surfaces of the reacted minerals using surface analytical techniques (XPS, AES, SEM, AFM in particular), which when combined with rates determined from solution shemistry using flow-through and column reactors will provide information on surface reaction mechanisms. In situ observations of reaacting mineral surfaces, using the AFM at lower temperature and new optical interferometric techniques at hydrothermal temperatures, will provide a bridge between the conventional kinetics experiments and ex-situ surface analysis. The new experimental findings on the kinetics of mineral-fluid interactions will be coupled with extensive molecular physics studies done in our group to ascertain the atomic dynamics governing geochemical processes. Our experimental work continues to lead the way in describing both dissolution and precipitation rates of major rock-forming silicates and aluminosilicates as a function of G, as well as being the first to measure precipitation rates in phases more complex than quartz. The non-trivial full rate laws that have been developed in our prior work are proving to be very important in successfully applying experimental rate data to model field cases, such as the Pijiguaos, bauxite deposit in Venezuela using accurate two-dimensional hydrodynamic fluid flow models. With the continuing work proposed here, the coupling of experiment, theory and models should result in the first completely quantitative physical and chemical model of water-rock interactions from the atomic level to the field setting under a wide set of geological environments including diagenesis in a dynamic sedimentary basin or the chemical evolution in a major bauxite deposit.