There are three main types of lava: a'a, pahoehoe and pillow lava. Each one flows at a different rate and has a different mineral composition. More »

Rocks formed from magma in the Earth's mantle are called igneous rocks. However, there are different types of magma. Lava rocks can be basalt, andesite or rhyolite. More »

The four types of lava are basaltic, andesitic, dacitic and rhyolitic. Basaltic is further divided into pillow, a'a and pahoehoe lava. The primary difference among these types is the amount of silica they contain. Higher... More »

One of the primary differences between pahoehoe and a'a lava formations is in terms of texture, where pahoehoe lava is smooth and viscuous while a'a lava is rough and rubbly. Pahoehoe lava also flows and cools down at a ... More »

The four types of lava are basaltic, andesitic, dacitic and rhyolitic. Basaltic is further divided into pillow, a'a and pahoehoe lava. The primary difference among these types is the amount of silica they contain. Higher... More »

Volcanoes erupt to release pressure built up in the magma chamber by expelling the magma as lava. Along with lava, a volcanic eruption releases ash and greenhouse gases such as sulfur dioxide and carbon dioxide. More »

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Cinder cone volcanoes generally spew lava dramatically when they erupt, though the eruptions are not particularly dangerous to human populations. Dramatic and beautiful as the eruptions may be, they are quite insignifica... More »