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
All-Ireland Intermediate Hurling Championship All-Ireland Intermediate Hurling Championship The GAA Hurling Intermediate All-Ireland Championship, known simply as the All-Ireland Intermediate Championship, is an annual inter-county hurling competition organised by the Gaelic Athletic Association (GAA). Effectively contested by the second string teams of the top inter-county hurling sides in Ireland, the tournament has taken place every year since 1997—having originally been run between 1961 and 1973. The final, currently held in July, serves as the culmination of a series of games played during the early summer, and the results determine which team receives the Michael Cusack Cup. The All-Ireland Championship has always been played on