QUANTIFICATION OF SUBMARINE LAVA-FLOW MORPHOLOGY THROUGH ANALOG EXPERIMENTS

We developed a technique for determining paleoeffusion rates and empla cement times for submarine lava hows, using observations of flow morph ology and estimates of eruption volume, eruption temperature, lava vis cosity, and preflow topography. Using laboratory simulations, and corr elating these results with sea-floor observations, four submarine lava -flow morphologies are considered to be diagnostic of specific effusio n rates: jumbled, folded, and lineated sheets, and striated pillows. W e applied this approach to the CoAxial flow, emplaced in less than 14 days on the Juan de Fuca Ridge in early summer, 1993, and we calculate d an effusion rate of similar to 100 m(3)/s, giving an emplacement tim e of similar to 10 days.