Volcanic Dust in Deep-Sea Sediments: Relationship of Microfeatures to Explosivity Estimates

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Science  13 Aug 1976:
Vol. 193, Issue 4253, pp. 576-579
DOI: 10.1126/science.193.4253.576


Particle size variations in a series of volcanic ash layers, deposited in high latitudes of the South Pacific during the past 2.5 million years, were earlier analyzed by using a model in which source cloud height and minimum volcanic paleoexplosivity are derived from downwind ash distribution. Examination of submicrometer morphological features of the volcanic glass shards reveals a clear relationship between what appear to be impact features on the glass surfaces and the independently derived paleoexplosivities, which suggests that this may be a simple means to characterize ash horizons and estimate relative volcanic explosivities.