XRF analyses were performed by D. Blatter and T. Teague using a SpecTrace 440 X-ray Spectrometer on powdered samples fused with lithium tetraborate flux. Standards were several natural lavas, including U.S.G.S. standards. Average uncertainties of one standard deviation based on replicate analyses are equal to the following percentages of the amounts present: SiO2 (0.2%), TiO2 (0.8%), Al2O3 (0.3%), FeOt (0.5%), MnO (1.7%), MgO (1.3%), CaO (1.2%), Na2O (3.9%), K2O (1.8%), and P2O5 (4.6%). Where reported, FeO and Fe2O3 by titration