GEOLOGY

Detailed explanation-1: -Composite cones are built of felsic to intermediate lava and shield volcanoes of mafic lava. Cinder cones are made of small fragments of a variety of compositions usually from a single eruption.

Detailed explanation-2: -The composition of magma that erupts at composite volcanoes is usually felsic (rhyolite) or intermediate (andesite).

Detailed explanation-3: -Since felsic magma is viscous, volcanic eruptions that form dacite or rhyolite are explosive and violent. The Archean felsic eruption may be assigned to Vesuvius eruption type in the present day. Submarine rhyolitic flows were widespread in the Archean but are uncommon in the modern volcanic environment.

Detailed explanation-4: -Mafic lava flows can travel quite far before solidifying completely, and the type of volcano that forms from mafic lava is called a shield volcano (Figure 9.9). Shield volcanoes are very broad at the base and have relatively gentle slopes.