Archean felsic volcanic rocks in felsic rocks. Timing of felsic volcanism and tectonic constraints can be identified by radiometric dating and isotopic analysis. In Archean, underwater eruptions of felsic lava were common. Submarine eruption is evident by coarse volcanic breccia formed in situ, hyaloclastite or underwater pyroclastic deposits (clastic rock, composed of tephra only). 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 Archean but it is uncommon in the modern volcanic environment. Viscous felsic eruption
Archean felsic volcanic rocks their mineral assemblages, rock chemistry and rock layer relationship in the sequences. Archean felsic volcanic rocks are utilised to date the timing of geological events and match distant rock units in separated Archean cratons. They are important to reconstruct Archean geological environments. Felsic granitoids are the most prevalent rock type in Archean terranes. These intrusive felsic igneous rocks include TTG suites (Tonalite-Trondhjemite-Granodiorite) that contributes over half the portion of Archean cratons. They have implications in finding how the felsic volcanic rocks were formed and related to the granitoids. Archean felsic volcanic rocks are only preserved in Archean cratons. A craton