Field Observations and Measurements of the Physical Properties of Oldoinyo Lengai Alkali Carbonatite Lavas, November 1988

Rheological and thermal properties of natrocarbonatite lavas from Oldoinyo Lengai have been measured in the field and in the laboratory. The viscosity, thermal diffusivity, specific heat capacity and latent heat of fusion are considerably lower than in basaltic lavas. A comparative study has revealed that lava flows erupted on Oldoinyo Lengai are smaller, though morphologically similar to basaltic lavas erupted on Mount Etna and Hawaii. Factors governing flow lengths, morphology and the development of compound flow fields on Oldoinyo Lengai are identical to those on basaltic volcanoes.