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Settling velocity of glass shards

1965; Elsevier BV; Volume: 12; Issue: 3 Linguagem: Inglês

10.1016/0011-7471(65)90006-9

1878-2493

Richard V. Fisher,

Geological formations and processes

Except for pumice fragments, glass shards of different types settle with velocities considerably less than quartz at 12 mm (1 φ), but at about the same velocity as quartz in sizes thn 116 mm (> 4· φ. Hence pipette analyses (based upon Stokes' law) are valid for samples with abundant bubble-wall shards, but not for samples with abundant pumice shards. The data may be directly applied to submarine volcaniclastic sedimentation. Sand-sized glass shards, for example, become quickly separated in water from their cogenetic grains. Therefore, in areas of successive eruptions, feldspar or quartz may reach the sea bottom at the same time as glass shards from a previous eruption.