Magmatic hydrothermal alteration systems

岩浆热液蚀变系统

• 批准号: 217095-2006
• 负责人: Lentz, David
• 金额: $ 1.45万
• 依托单位: University of New Brunswick
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=366238
• 关键词: Magmatic; hydrothermal; alteration; systems

This specific research application focuses on complex infiltrative metasomatic reaction systems, which indirectly relates to the spectrum from magmatic volatile evolution through to the distal precipitation of metals; this proposal is an extension of his research on skarn systems that has had several key impacts, which most notably are: 1) some important phase relations have been highlighted in mixed volatile, infiltrative contact metasomatic systems, 2) permeability evolution during solution-hostrock reaction coupled with and analysis of physiochemical reactions, and 3) the provocative petrogenetic interpretation of some derivative igneous rocks, their gases, and eruptive style has a wide range of implications. These contributions are all interrelated as the complex feedback mechanisms (i.e., CO2 back infiltration from decarbonation fronts) affect fluid-mineral-melt phase relations (i.e., lowering P(H2O)) that affect gas speciation, vapour saturation and critical behaviour, metal partitioning, i.e., Au, W, Mo, etc. through to eruptive processes, including magma-volatile behaviour, eruptive dynamics, emplacement rates, etc. all of which are critical to interpreting various parts of these systems. The mass-balance analysis of various infiltrative skarns compliments this research, by detailing the proportion of material added to and (or) removed from the metasomatic system, which then constrains the degree of fluid-rock reaction associated with skarn formation, the elemental mobility (fluid-rock ratios) observed, alteration zoning produced, and the mechanisms responsible for these endo- and exo-contact reaction zones; typically infiltrative skarns form some of the richest mineral deposits due to these complex processes. The volatile fluxing and syntectic processes require a better understanding of high-T, skarn-forming processes, including H2O-CO2  infiltrative decarbonation equilibria, carbonate fluxing relations, as well as the reactions that govern differential degassing of carbonated silicate magmas and their dynamic explosive emplacement processes, including pyroclastic volcanism.

这项具体的研究应用侧重于复杂的渗透交代反应系统，这间接涉及到从岩浆挥发性演化到金属远端沉淀的光谱;这项提议是他对矽卡岩系统研究的延伸，该研究产生了几个关键影响，其中最显着的是：1）在混合挥发性、渗透性接触交代体系中，一些重要的相关系已得到强调，2）溶解-围岩反应过程中渗透率的演化与物理化学反应的耦合分析; 3）对一些衍生火成岩及其气体的成因解释，爆发式风格具有广泛的含义。这些贡献都是相互关联的，因为复杂的反馈机制（即，来自脱碳前沿的CO2回渗）影响流体-矿物-熔体相关系（即，降低P（H2O）），其影响气体形态、蒸汽饱和度和临界行为，金属分配，即，从Au、W、Mo等到喷发过程，包括岩浆挥发行为、喷发动力学、侵位速率等，所有这些对解释这些系统的各个部分都至关重要。各种渗透性夕卡岩的质量平衡分析补充了这项研究，通过详细说明添加到交代系统和（或）从交代系统中去除的物质的比例，然后限制与夕卡岩形成相关的流体-岩石反应的程度，元素的流动性（流体-岩石比），蚀变分带的产生，以及内外接触反应带的形成机制;由于这些复杂的过程，典型的渗透性矽卡岩形成一些最丰富的矿藏。挥发性的熔融和syntaxis过程需要更好地了解高温，矽卡岩形成过程，包括H2O-CO2渗透脱碳平衡，碳酸盐熔融的关系，以及控制碳酸盐硅酸盐岩浆和动态爆炸侵位过程，包括火山碎屑火山作用的差异脱气反应。