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

钾长石是大陆岩浆岩中常见的一种，它的成分可以记录它从熔体中生长时所经历的强烈条件。研究小组将根据透长石成分校准一个依赖于水的地质温度计。校准将适用于确定一些世界上最重要和最好的研究套件，包括大量（1000立方公里）熔结凝灰岩和岩基岩体的结晶条件。来自西班牙裔服务机构索诺马州立大学的六名本科生将参与该项目，其中包括3名来自一个促进STEM领域向代表性不足的群体发展的项目的本科生。三名来自高中实习项目的学生将参加。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。硅质岩浆是行星分化的最终产物，可以大量喷发。大量的火山喷发要求地壳中必须存在短期或长期的大量糊状物（晶体+熔体）。然而，关于这些系统的起源和寿命的争论仍在进行中，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辩论中没有得到充分利用，主要是由于缺乏适当的模型。该项目将涉及新的钾长石湿度计/温度计的实验校准，这将限制条件（即，温度、压力、H2O含量）的形成、储存和提取。来自西班牙裔服务机构索诺马州立大学的六名本科生将参与该项目，其中包括3名来自一个促进STEM领域向代表性不足的群体发展的项目的本科生。三名来自高中实习项目的学生将参加。三名本科生戴维斯，西班牙裔服务机构，也将参加。这个奖项反映了NSF的法定使命，并已被认为是值得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的支持。

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.