Hydrous Intermediate Magmas

CarmichaelEAR-0125159虽然表示水在岩浆中的溶解度作为P、T和液体组成的函数的简单表达式对于许多含水相平衡实验来说是足够的，但它对富铁玄武岩和更高的压力的推断是有问题的。使用我们的内部加热压力容器，建议测量两个哥伦比亚河玄武岩的水溶解度作为P&P；T的函数，以确保溶解度算法对不同二氧化硅浓度的富铁液体的组成外推。已公布的对岩浆中溶解水体积的直接测量将被包括在修订的算法中(早期公式中的回归变量)，以确保溶解度关系的压力依赖性外推到已公布的高压实验中。与俯冲有关的含角闪石的中间熔岩总是比其不含角闪石的同系物氧化得更严重。其原因尚不清楚，可能是喷发时溶解的水与硫磺物种结合排出的间接原因。这将通过使用一种新开发的X射线荧光技术来测试，以测量大量空中结晶熔岩中的硫浓度，这些熔岩的氧化还原状态是众所周知的。

CarmichaelEAR-0125159Although the simple expression representing the solubility of water in magmas as a function of P,T and liquid composition, is adequate for many hydrous phase-equilibrium experiments, its extrapolation to iron-rich basalts and to higher pressures is problematic. Using our internally heated pressure vessel, it is proposed to measure the water solubility in two Columbia River basalts as a function of P & T to make secure the compositional extrapolation of the solubility algorithm to Fe-rich liquids of varying silica concentration. Published direct measurements of the volume of dissolved water in magmas will be included in the revised algorithm (a regressed variable in the early formulation) to ensure that the pressure dependence of the solubility relationship extrapolate to published high pressure experiments.Hornblende-bearing intermediate lavas associated with subduction are always more oxidized than their hornblende-free associates. The reasons for this are unknown and could indirectly result from the expulsion of dissolved water on eruption in combination with a sulfur species. This will be tested by using a newly developed X-Ray fluorescence technique to measure the sulfur concentration in a large collection of sub-aerial crystalline lavas for which the redox state is well known.