General patterns of flow field growth: Aa and blocky lavas

摘要: Lava flow fields consist of one or more flows. Four ideal emplacement regimes are recognized: (a) that for single flows and (b) dominated by (1) widening, (2) thickening, (3) lengthening, as a result generating new Most aa blocky lavas belong to the field widening single-flow regimes. These two analyzed assuming advance is controlled distal core flow, where motion treated steady, uniform, laminar. Because low deformation rates, also approximated Newtonian fluid. Widening and, possibly, lengthening ultimately limited crustal resistance. After critical cooling interval, generated from upper reaches field. A simple relation derived linking dimensions underlying slope eruption duration, independent terms involving gravity lava chemistry rheology. The well describes data several volcanoes (involving compositions K phonolitic tephrite dacite). This supports premise overall growth systematic suggests such may be predictable at time scales greater than, similar to, times major