Cogenetic Origin of Magmatic Enclaves in Peralkaline Felsic Volcanic Rocks from the Sanshui Basin, South China

Centimeter-scale magmatic enclaves are abundant in peralkaline felsic volcanic rocks the Sanshui Basin. Their lithology is mainly syenite and syenitic porphyry, they comprise alkali feldspar amphibole, which similar to mineral assemblage of host trachyte comendite. The SiO2 content ~63 wt%, that but lower than Thermobarometric calculations showed crystallized at temperature pressure conditions as their trachyte. results mass-balance modeling MCS indicate likely experienced an approximately 74% fractional crystallization from basaltic parental magma. Combined with assemblages geochemical characteristics trachyte, we think resulted situ trachytic magma shallow crust had a cogenetic origin rocks, means were derived identical chamber was formed different batches mixing/mingling. recharge mixing triggered eruption eruption. may have been disaggregated by ascending brought surface enclaves. provide unique information on magmatism evidence