Abstract:

The Hulin basin is a Meso-Cenozoic, down-warped, faulted basin located in the eastern part of Heilongjiang Province, which superimposed on the Jiamusi uplift. The structural evolution can be divided into 3 stages, and the structural characteristics and deformation mechanism for each stage are significantly different. 1)A series of separate NE trending half-graben fault depressions developed at the NW-SE-directed extensional stage in the Early Cretaceous. 2)Some of the early depression-controlling normal faults reversed and formed inversion structures during NW-SE compressional stage in Late Cretaceous, the Hulin basin switched into a depression basin with multi-depocenters under the NW-SE-directed compression depression. 3)The tectonic framework changed significantly at the NNW-SSE-directed compression stage in the Paleogene-Quaternary, not only some of the early depression-controlling normal faults reversed, resulting in large-scale inversion structures, but also the NEE trending large-scale thrust faults (Dunhua-Mishan fault zone) and fault-propagation-related folds between the Qihulinhe depression and the central uplift formed, which together controlled the formation and sedimentation of the basin, and the Hulin basin transformed into a NNE trending, down-warped compressional basin which are composed of the central uplift, the south and the north depressions. The Northeast China has been always in an active continental margin tectonic setting since the Cretaceous. The formation mechanism of Hulin basin, which is included in the eastern basin groups of the Northeast China, is related to the subduction of Izawa Naqi plate, the Pacific plate to the Eurasian plate. The Dunhua-Mishan fault zone are NE trending sinistral strike-slip faults, and the NE segment near the the Hulin basin transform into the NEE trending thrust fault, the thrusting of the NE segment of the Dunhua-Mishan fault zone may be related to the NEE trending transformed compression of the NE trending sinistral strike-slip of the fault. The Dunhua-Mishan fault zone developed at the Hulin period of Eocene-Oligocene, and showed continuously activities from the Hulin period to Quaternary.

Key words: structural feature, deformation stage, deformation time, basin formation mechanism, overthrusting structure, Hulin basin, northeastern segment of Dunhua-Mishan fault zone