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Volcanic sand of recent basaltic lava: along Hawaii's south coast, basaltic lava, up to 1100 deg C hot, is shock-cooled upon contact with the sea water. Glassy beads and highly porous basaltic "spatter" form which are quickly ground up into shards by shoreline surf and swash. The black beach becomes extremely hot under the morning sun.
Composition:
Dominantly light green volcanic glass, isotropic in polarized light. A few colourful clinopyroxen crystals (maybe olivine as well ?) and a few microlithic VRFs.
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Macroscopic view, line in |
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A coarse-grained, moderately to poorly sorted, extremely angular volcanic sand of recent basaltic lava. The extreme angularity and the preservation of many partial bubble outlines is unusual in sands but highly diagnostic in the interpretation in sandstone provenance. Medium to coarse sand (250 to 1250 μm)
Sample Number:
number of the sample heubeck0085
Collector:
Collector of the sand, Institution Christoph Heubeck, Institut für Geologische Wissenschaften, Freie Universität Berlin
Date:
Date of sampling1991
Comments:
Further comments on the sand, depositional history, ecc.Along Hawaii's south coast, basaltic lava, up to 1100 deg C hot, is shock-cooled upon contact with the sea water. Glassy beads and highly porous basaltic "spatter" form which are quickly ground up into shards by shoreline surf and swash. The black beach becomes extremely hot under the morning sun
