STRATIGRAPHIC CHARACTERISTICS AND DIAGENETIC AGE OF THE PROTEROZOIC ROCKS IN XIAOXINGANLING-ZHANGGUANGCAILING REGION, HEILONGJIANG PROVINCE

The Xiaoxinganling-Zhangguangcailing region is tectonically located in Jiamusi-Xingkai massif in the southern margin of Siberia plate. The Proterozoic strata include the Paleoproterozoic Dongfengshan rock group and Erzhan rock group, the Mesoproterozoic Heilongjiang rock group and the Neoproterozoic Zhangguangcailing rock group. Each rock group represents the active(volcanic) sedimentation under the continental-continental margin extensional environment. Because of tectonic reformation, the structural contact between strata shows general order and local disorder. Geological and isotopic data indicate the diagenetic age of Proterozoic Eon. The rocks are generally distributed in N-S direction in the west side of the Jiamusi massif, obviously controlled by the forming-accretion evolution of the Jiamusi massif. The occurrences of the rocks correspond to tectonic events of the closure of fault-depression, continental accretion and syntectonic magmatic orogeny, reflecting the tectonic system of multiple opening-closing and polycyclic orogeny.