CHARACTERISTICS AND GENESIS OF THE LIPARITIC MORTAR-LAVA IN SIMUKE AREA OF NORTHERN DAXINGANLING

A special kind of liparitic mortar-lava with the texture of both lava and ignimbrite is developed in Simuke area, Northern Daxinganling.The rock is characterized by enriched Si, alkaline and LREE, Na₂0/K₂0=0.61-0.82, with relatively great negative Eu anomaly, high Rb and Th content and low Ba and K.It geochemically resembles the liparite of the same period, but with significant different in their lithofacies.They were probably both originated in post-orogenic extension environment, and might be the polymorphs formed in different emplacement of magma.