Geology of Ascension Island other volcanic islands, which only have a few mafic and felsic endmembers such as basalt or rhyolite, Ascension has a full-range from some of the most mafic to most felsic. This includes basalt, hawaiite, mugearite, benmoreite,trachyte and rhyolite. Potassium-argon dating indicates that the oldest rocks exposed above the water are one million year old rhyolites. Geologists have divided the island's mafic and felsic rocks into different named sequences and sub-divided mafic rocks based on their ratio of zirconium and niobium. The Sister's Peak region in northwest Ascension has intermediate mafic lava flows, scoria cones and mafic ash fall deposits near
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,