Report on Late Paleozoic bimodal volcanic associations discovered in Northern Mongolian Rift zone

1.Objectives Within the Northern-Mongolian–Transbaikalian Rift system,bimodal volcanic associations with felsic agpaitic rocks are widespread,often accompanied by alkaline granites plutons.There are two segments in the Rift system structure–Northern-Mongolian with length of 600 km and Western-Transbaikalian with length of 800 km on latitude.Most western appearances of alkaline granites and bimodal magmatism are Bat-Tsengel,Upper-Hanui and Orkhont plutons(Vorontsov AA et al.,2007).