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

The tectonic settings of the different stages of the magmatic activity in the middle-south section of the Da Hinggan Mts. are analyzed through measuring 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 basic-ultrabasic rocks containing mantle-source enclaves, middle-upper crust extension marked by intrusion of the Early-Middle Jurassic diobase dike swarms, dramatic ruption of the Late Jurassic trachitic volcanic rocks, the Early Cretaceous nonorogenic alkalic-subalkalic granite invasion and the formation of the basic dike swarms and basalts. It is thus inferred that the uprise of the Da Hinggan Mts. in the Mesozoic is closely reiated to the upwelling of the deep magma in the mantle upwarping settings.