Abstract provided by author:
On the bases of the field observations and chemical composition of the rocks, crystal fractionation, batch melting melting of sedimentary materials and magma mixing, probably played an important role in the origin of the alkaline rocks of the Aris area
The phonolites of the study area are porphyritic, holocrystalline, undersaturated subvolcanic rocks with an agpaitic index of 1. 1 and containing uncommon minerals. Most trachytes occur as pyroclastic or lithic breccias, containing various amount of country rock xenoliths. All the alkaline rocks of the study area are enriched in LREE and depleted in HREE, but large differences exist in chemical composition of the phonolites and the trachytes