Mafic The mafic rocks also typically have a higher density than felsic rocks. The term roughly corresponds to the older "basic rock" class. Mafic lava, before cooling, has a low viscosity, in comparison with felsic lava, due to the lower silica content in mafic magma. Water and other volatiles can more easily and gradually escape from mafic lava. As a result, eruptions of volcanoes made of mafic lavas are less explosively violent than felsic-lava eruptions. Most mafic-lava volcanoes are shield volcanoes, like those in Hawaii. Mafic Mafic is an adjective describing a silicate mineral or igneous rock that is rich in
Archean felsic volcanic rocks is an ancient stable continental block. Also, a craton has survived from plate tectonics that pull apart, collide or tear continents. On average, the felsic volcanic rocks only contribute to ~15-20% in volcanic rocks of greenstone belts. "See Figure 2 and Table 1 for Examples of Archean felsic volcanic rocks occurrence." All Archean felsic volcanic rocks are distributed in greenstone belts. In Archean cratons, greenstone belts represent supracrustal rocks formed at the Earth's surface and the belts are dominated by volcano-sedimentary sequences. Some volcanic sequences can be several kilometers thick, such as the Warrawoona Group of Eastern Pibara Craton. However,