Tectono-thermal evolution of middle-south section of the Da Hinggan Mountains

The tectonic settings of the different stages of the magmatic activity in t he middle-south section of the Da Hinggan Mts. are analyzed through measuri ng the isotopic ages of the Mesozoic volcano-plutonic rocks from this area, and thus the tectono-magmatic evolution series are consequently determined as the initial mantle upwelling marked by the Late Triassic invasion of ba sic-ultrabasic rocks containing mantle-source enclaves, middle-upper crust extension marked by intrusion of the Early-Middle Jurassic diobase dike swa rms, dramatic ruption of the Late Jurassic trachitic volcanic rocks, the Ea rly Cretaceous nonorogenic alkalic-subalkalic granite invasion and the form ation of the basic dike swarms and basalts. It is thus inferred that the up rise of the Da Hinggan Mts. in the Mesozoic is closely related to the upwel ling of the deep magma in the mantle upwarping settings.