The Paleogene Stratigraphic Sequence And Basins Evolution In The Eastern Part Of Jilin And Heilongjiang

Paleogene basins in the Eastern part of Jilin and Heilongjiang were a serous of rift valley which mainly developed along the Dun-Mi and Jia-Yi Faults.From the south to the north along the Dun-Mi Fault are Huadian basin, Pingyangzhen depression (the Eastern part of Jixi basin), Qihulinhe depression (the Northern part of the Hulin basin); From the south to the north along the Jia-Yi Fault are Yitong-Shulan depression, Fangzheng and Tangyuan depression, which are the most important coal and oil resources in northeast part of China.Based on summerizing data of stratigraphy and paleontology in the region systematically, The dissertation classified and corralated the strata sequence of the Cenozoic basins in the Eastern part of Jilin and Heilongjiang, moreover, resumed the paleogeography structure of these basins.Taking region rock strata sequence and fossil assemblages as the key point , I discussed the forming and evolving characteristics and patterns of Paleogene basins, which has importernt significances for researching fundamental geology within the area, and perspective evaluation of the petroleum and gas. Combining the tectonic background of basin formation and the foundation of the strata, the author identified the extrusion and reversion events of Paleogene, it is certain that the Paleogene is an another important basin evolving sequence and a prospecting oil and gas exploration aiming layer.The dissertation summarized the sequence of lithostratigraphy, biostratigraphy and the evolving patterns of the basins in the region, namely: 1. Based on discussing each formations of paleogene, the author summarized the lithostratigraphic sequences of the Paleogene basins in the researching region.2. Systematically summing up paleogene fossil assemblages in the Eastern part of Jilin and Heilongjiang, there are 3 plants assemblages, 3 Palynology assemblages and 1 Ostracods assemblages.3. Through systematically correlating the strata of Paleogene basins in the Eastern part of Jilin and Heilongjiang. We can conclude that the age of the depressions along Dun-Mi, and Jia-Yi fault are different, it become newer from the Bohai-bay basin to the northern basins.4. Combining the regional tectonic background and the strata sequence, we identified the extrusion and reversion events of Paleogene, and pointed out that Paleogene as an important basin evolving sequence surrounding Daqing exploring region.5. Summarized the basins evolving phases and pattern in Eastern part of Jilin and Heilongjiang; it is certain that the Paleocene as a whole behaved as a rifting phase, from Eocene to Oligocene, the stress of the whole area changed to be extrusion, and the basin become depression phase; at the end of the Oligocene, there was a regional reversion event, which ended the evolution of the Paleogene basin.