Archean felsic volcanic rocks often causes pyroclastic flow (hot, dense gas with volcanic fragments) instead of fluid lava flow. However, if the rhyolitic lava is still molten during eruption, it can behave and flow like fluid flow. Felsic lava flow and lava dome are the two common types of underwater deposits formed by Archean felsic volcanic rocks (Fig. 4). Documented Archean lava structures are distinctive from post-Archean felsic lava because underwater eruptions are so rare in post-Archean. The dacitic or rhyolitic lava flows are quenched right after the eruption. When water is in touch with the flow, the lava quickly cools down. Finally, The
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,