Abstract: On Jiamusi-Mongolia block, the contact relationship of Late Paleozoic and related strata contains abundant tectonic information. We systematically combed these data and discussed the formation and evolution of Jiamusi-Mongolia block. The angle unconformities can be found under Xibiehe Formation on the southern margin of Jiamusi-Mongolia block, Woduhe Formation on the northern margin, and Heitai Formation on the eastern margin. These angle unconformities under the Late Silurian-Early Devonian strata reveal a significant tectonic movement, indicating that the Jiamusi-Mongolia block was formed in Late Silurian-Early Devonian. The contact relationship between the strata of Devonian, Carboniferous and Permian are all conformable, which manifests a stable subsidence period during Devonian-Permian on the Jiamusi-Mongolia block. The parallel unconformities under the bottom of the Late Permian Linxi Formation and under the bottom of the Early Triassic Lujiatun Formation are the significant mark of the collision and collage between Jiamusi-Mongolia block and North China plate. The parallel unconformity surface, the above Molasse Formation, and the stratigraphic sequence change from marine to continent during Middle-Late Permian indicate a foreland basin sedimentary environment of Linxi Formation. The angle unconformity under the bottom of Lujiatun Formation and the characteristics of Molasse Formation in conglomerate indicate a continuous progressive orogeny. The angle unconformity under the bottom of Late Triassic Dajianggang Formation indicates the end of the orogeny and the development of Jiamusi-Mongolia block as an independent block.

Key words: Late Paleozoic, contact relationship of strata, conformity, unconformity, Jiamusi-Mongolia block, North China plate