Water in Magmas: Experimental Constraints on the Stability of Hornblende in Basalts and Basaltic Andesites

9706129卡迈克尔以前的工作已经确定，墨西哥西部安山岩熔岩的斑晶组合强烈地受到岩浆所含水浓度的影响。墨西哥中部的玄武岩和玄武岩安山岩可能含有角闪石斑晶，建议对角闪石稳定的区域的P-T条件和液体中的水浓度进行量化。此外，辉石和橄榄石的斑晶，通常没有斜长石，将被用来限制玄武岩和没有角闪石的玄武岩安山岩中的水浓度。在内部加热的压力容器中，将用氧逸度来校准角质混合物中的铁-铁比例，在压力容器中，快速淬火将液体保存为玻璃。此外，墨西哥中部安山岩-玄武岩的地质年代和环境知之甚少，因此将在墨西哥米却肯州的齐塔库阿罗地区完成测绘和取样。

9706129 Carmichael Previous work has determined that the phenocryst assemblages of andesitic lavas in western Mexico are strongly influenced by the concentrations of water that the magmas contain. Basalts and basaltic andesites from central Mexico may contain hornblende phenocrysts and it is proposed to quantify the P-T conditions, together with the water concentration in the liquids, in the regimes in which hornblende is stable. In addition, phenocrysts of pyroxene and olivine, often without plagioclase, will be used to constrain the water concentrations in basalts and basaltic andesites without hornblende. Ferric-ferrous ratios in the hornblendes will be calibrated with oxygen fugacity in an internally heated pressure vessel in which the rapid quench preserves the liquid as a glass. In addition, the geological age and environment of andesites-basalts in central Mexico are so poorly known that mapping and sampling will be completed in Zitacuaro region of Michoacan, Mexico.