Collaborative Research: A New Sanidine-Liquid Hygrometer: Experiments, Calibration and Applications

钾长石是大陆岩浆岩中常见的成分，它的成分可以记录它在从熔体中生长时所经历的强烈条件。研究小组将根据透水石成分来校准依赖于水的地温计。该校准将适用于确定世界上一些最重要和研究最透彻的套件的结晶条件，包括大量（1000立方公里）火成岩和岩基岩体。来自拉美裔服务机构索诺玛州立大学的 6 名本科生将参与该项目，其中 3 名本科生来自向弱势群体推广 STEM 领域的项目。来自高中实习项目的三名学生将参加。来自西班牙裔服务机构戴维斯的三名本科生也将参加。该项目将产生新的相平衡结果、适用于含透长石和斜长石岩浆的湿度计，以及估算深成岩平衡温度和 H2O 含量的新方法。硅质岩浆代表了行星分化的最终产物，可以大量喷发。大量硅质喷发要求地壳中必须存在短期或长期的糊状物质（晶体熔化）。然而，关于此类系统的起源和寿命的争论仍在继续，数值模型、同位素和微量元素数据以及深成和火山记录的观点相互矛盾。钾长石记录的密集变量在这场争论中并未得到充分利用，这主要是由于缺乏合适的模型。该项目将涉及新型钾长石湿度计/温度计的实验校准，该湿度计/温度计将限制各种硅质岩浆的形成、储存和提取的条件（即温度、压力、H2O 含量）。来自拉美裔服务机构索诺玛州立大学的 6 名本科生将参与该项目，其中 3 名本科生来自向弱势群体推广 STEM 领域的项目。来自高中实习项目的三名学生将参加。来自西班牙裔服务机构戴维斯的三名本科生也将参加。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

The composition of potassium feldspar, a common in continental magmatic rocks, can record the intensive conditions it experiences as it is growing from a melt. The research team will calibrate a water-dependent geothermometer based on sanidine compositions. The calibration will be applicable to determine the conditions of crystallization of some of the world's most-important and best-studied suites, including voluminous (1000 cubic kilometers) ignimbrites and batholithic plutons. Six undergraduates from Sonoma State, a Hispanic-serving institution, will participate in the project, including 3 from a program that promotes STEM fields to under-represented groups. Three students from a high-school internship program will participate. Three undergraduates from Davis, a Hispanic-serving institution, will also participate. This project will generate new phase equilibria results, a hygrometer applicable to sanidine- and anorthoclase-bearing magmas, and a new method for estimating the equilibration temperatures and H2O contents of plutonic rocks. Silicic magmas represent the final products of planetary differentiation and can erupt in enormous volumes. Voluminous silicic eruptions require that short- or long-lived volumes of mush (crystals + melt) must exist in the crust. However, there is ongoing debate about the origins and lifespans of such systems, with conflicting views from numerical models, isotopic and trace element data, and the plutonic and volcanic records. The intensive variables recorded by potassium feldspar have been underutilized in this debate, largely due to a lack of appropriate models. This project will involve experimental calibration of a new K-feldspar hygrometer/thermometer that will constrain the conditions (i.e., temperature, pressure, H2O content) of formation, storage, and extraction of a broad range of silicic magmas. Six undergraduates from Sonoma State, a Hispanic-serving institution, will participate in the project, including 3 from a program that promotes STEM fields to under-represented groups. Three students from a high-school internship program will participate. Three undergraduates from Davis, a Hispanic-serving institution, will also participate.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.