However, ultramafic and mafic units make up the major volume of the volcanic units. Some volcanic sequences can be several kilometers thick, such as the Warrawoona Group of Eastern Pilbara Craton. In Archean cratons, greenstone belts represent supracrustal rocks formed at the Earth's surface and the belts are dominated by volcano-sedimentary sequences. See Figure 2 and Table 1 for Examples of Archean felsic volcanic rocks occurrence.ДЄll Archean felsic volcanic rocks are distributed in greenstone belts. On average, the felsic volcanic rocks only contribute to в‰€15-20% in volcanic rocks of greenstone belts. Also, a craton has survived from plate tectonics that pull apart, collide or tear continents. A craton is an ancient stable continental block. 4 Relationships between Archean felsic volcanic rocks and granitoidsДЄrchean felsic volcanic rocks are only preserved in Archean cratons.They have implications in finding how the felsic volcanic rocks were formed and related to the granitoids. These intrusive felsic igneous rocks include TTG suites ( Tonalite-trondhjemite-granodiorite) that contributes over half the portion of Archean cratons. ДЇelsic granitoids are the most prevalent rock type in Archean terranes. They are important to reconstruct Archean geological environments. ДЄrchean felsic volcanic rocks are utilised to date the timing of geological events and match distant rock units in separated Archean cratons. They can be distinguished by their mineral assemblages, rock chemistry and rock layer relationship in the sequences. The composition of Archean felsic volcanic rocks are equivalent to a spectrum between dacite and rhyolite. Thus, felsic volcanic rocks are rare members in the Archean terranes.ДЄrchean felsic volcanic activities commonly occur in submarine environments. Nonetheless, mafic volcanic rocks (such as basalt and komatiite, silicate content <52% ) occupy about 50% in the greenstone belts. Felsic volcanic rocks are rare in the early Earth and only contribute to less 20% of rocks in the Archean greenstone belts worldwide. ДЄrchean felsic volcanic rocks are distributed only in the preserved Archean greenstone belts, where deformed sequences of volcanic-sedimentary rocks are common. ДЄs the Archean Earth was hotter than the present, formation of felsic volcanic rocks may differ from the modern plate tectonics. Given that the Earth formed at ~4.5 billion year ago, Archean felsic volcanic rocks provide clues on the Earth's first volcanic activities on the Earth's surface started 500 million years after the Earth's formation. The term ' felsic' means that the rocks have silica content of 62вЂ“78%. ДЄrchean felsic volcanic rocks are felsic volcanic rocks that were formed in the Archean Eon (4 to 2.5 billion years ago). Felsic eruption forms felsic volcanic rocks near the volcano and a spectrum of volcano-sedimentary sequence in the sea in Archean. A schematic diagram showing the formation environment of Archean felsic volcanic rocks.

Felsic intrusive ternary diagram