摘要: Deep sea pillow basalts dredged from the ocean floor show that vesicularity changes with composition as well depth. Alkalic are more vesicular than tholeiitic erupted at same The data, when related to experimentally determined solubility of water in basalt, indicate K-poor oceanic tholeiites originally contained about 0.25 percent water, Hawaiian intermediate K-content, 0.5 and alkali-rich basalts, 0.9 water. Analyses fresh basalt pillows a systematic increase H2O+ rocks become alkalic. contain 0.06–0.42 H2O+, tholeiites, 0.31–0.60 alkali rich 0.49–0.98 H2O+. contents K2O, P2O5, F, Cl directly an content such 1.0 weight K2O is 1.58 percent, P2O5 0.55 F 0.07 0.1 percent. measured deuterium on rim one −6.0 (relative SMOW); this value, which similar other indications magmatic suggests no appreciable was absorbed by during or subsequent eruption floor.