aa lava

aa lava

[ä′ä ′lä·və]
(geology)
References in periodicals archive ?
Specific topics include strike-slip fault, terminal moraine, tsunami, weathering, Yellowstone National Park, mass wasting, Kaapvaal craton, ichnofossils, greenstone belts, geodesy, El Nino, desalination, carbon cycle, and aa lava. Five appendixes contain the periodic table of elements, the geologic time scale, classification of species, solar system data, and evolution of life and the atmosphere.
And apart from the noxious, indeed potentially fatal, sulphurous gases and the risk of falling on the razor-sharp aa lava flows or collapsing through into veins of molten rock, such access is comparatively safe.