<P> Lava is the molten rock expelled by a volcano during an eruption . The resulting rock after solidification and cooling is also called lava . The molten rock is formed in the interior of some planets, including Earth, and some of their satellites . The source of the heat that melts the rock within the earth is geothermal energy . When first erupted from a volcanic vent, lava is a liquid usually at temperatures from 700 to 1,200 ° C (1,292 to 2,192 ° F). </P> <P> A lava flow is a moving outpouring of lava created during a non-explosive effusive eruption . When it has stopped moving, lava solidifies to form igneous rock . The term lava flow is commonly shortened to lava . Although lava can be up to 100,000 times more viscous than water, lava can flow great distances before cooling and solidifying because of its thixotropic and shear thinning properties . </P>

What do you call rocks that form when flowing lava solidifies