Petrology,Geochemistry and Genesis of Kuiqi Granite Batholith

The Kuiqi granite batholith outcrops in the vicinity of Fuzhou City,Fujian Province andconstitutes one of the typical alkali granitic complexes in the“Belt of Miarolidc Granites”ex-tending along the southeast coast of China.The complex is believed to have been emplacedat higher levels of the crust in a tensional fault environment.Petrographically it is composedmainly of aegirine-arfvedsonite granites with early biotite granites scattered.Miarolitic struc-ture and granophyric texture are commonly ob served.The Rb-Sr isochron age of the complexis 107.65 m.y.Both petrological and petrochemical studies show that the Kuiqi granite is ofA-type.Data on chemical composition,REE pattern and transition dements reveal that thereis a close genetic connection between granites and associated volcanic rocks.Thus,syntexis-type(Ⅰ-type)granite,A-type granite and volcanic rocks form a cogenetic“trinity”,in whichthe A-type granite is usually the latest member of the volcanic-intrusive series.