Moore, J. Water-saturated densities of subaerial lava flows occurring above m depth have the broadest range because of the large density variation within a single lava flow.
Water-saturated densities commonly range from 2. Dikes and sills range from 2.
Densities of hyaloclastite commonly range from 2. The low-density of most hyaloclastite is due primarily to palagonitization of abundant glass and presence of secondary minerals in the interstices between fragments.
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Four principal zones of pillow lava, separated by hyaloclastite, occur in the drill core. The shallowest m is paradoxically the densest, averaging 3.
The second m is decidedly the lightest, averaging 2. The third m and fourth bottom at m are high, averaging 2. The first pillow zone includes degassed pillows i.
These pillows are poor in vesicles, because the subaerial, one-atmosphere vesicles were compressed when the flow descended to deeper water and higher pressure. The second low-density, non-degassed pillow zone is the most vesicle-rich, apparently because it was erupted subaqueously at a shallow depth.