The Early Createous Strata Sequence And Basin Evolution In Easten Heilongjiang Province, China

The thesis selects the Early Cretaceous basins-Jixi Basin, Hulin Basin and Boli Basin surrounding Daqing exploring region as to be main studying points. Based on studying the regional rock strata sequence, the author wants to discuss the basic rule of basic evolution. These conclution may have great theoretical and practice significants to the basin geology study in Northeast China, basins evolution and oil and gas perspective evaluation surrounding Daqing.The main content of the thesis compose 10 aspects:1. Based upon summarizing systematically the former references about the regional stratigraphy and paleotology, the author has discussed the Early Cretaceous stratigraphic sequences and their correlations of the eastern basins surrounding Daqing exploring region.The thesis narrated more than 10 formations, including their defination, the character of their basic rock assemblages and stratotype section.According to the international stratigraphic chart placing the boundary between Jurassic and Cretaceous at 145±4.5Ma, and a great deal achievements made this 10 years in paleotology studying and Igneous rock isotope age measuring in Northeast China, the thesis places Jixi Group and Longzhaogou Group to be Early Cretaceous.2. After defining the strata sequence of Jixi Group, Longzhaogou Group, the thesis emends the name of formation units of the two groups: the ascending order of Jixi Group is Didao Formation, Chengzihe Formation, Muling Formatin and Dongshan Formation; the ascending order of Longzhaogou Group is Peide Formation, Qihulin Fomation, Yushan Formation and Zhushan Formation. The thesis also makes sure the character of the rock assemblages of each formation stratigraphic units and paleotlogy, and the rule of their age and distribulations. All these can offer evidences to the resuming of the anchetype basin.3. After the petrology, paleotology and age contrast to the Jixi Group and Longzhaogou Group, thesis considered that Didao Formation correlated with Peide Formation belong to Berriasian to Valanginian; Chengzihe Formation correlated with Qihulin Formation, Yunshan Formation belong to Valanginian to Barremian; Muling Formation correponding to Zhushan Formation belong to Middle Barremian-Early Albian; and Dongshan Formation belong to Middle-Late Albian.4. Make sure that petrology and strata sequences of Dongshan Formation belongs to which. structure strata. Dongshan Formation conformities with the undersiding Muling Formation in new JiD2, also conformitation in region; and it unconformities with upsiding Houshigou Formation.These indicate that Dongshan Formation and Muling Formation belong to the same strcture strata-Jixi Group.5. According to the information of region and drilling, make sure that eastern basins have three stratigraphic sedimentary sequences in Mesozoic and Cenozoic. They are the sedimentary of Early Cretaceous Jixi Group and Longzhaogou Group, Late Cretaceous Huashan Group, Cenosoic Hulin Formation and Fujin Foemation, respectively. And Hulin Basin mainly a Cenozoic basin.It has the most thickest sedimentary in Paleocene, to more than thousands, contains oil shales and coals, and can be a good oil-gas exploring stratum.Based on contained paleotology fossils, the thesis put it in Oligocene.The upsiding strata is Fujin Pormation, mainly containing continental appearance fractures and coals.6. Based on the compositive stratigraphics theory, that regional and basins strata of the Jixi Basin, Boli Basin and Hulin Basin were comprehensive contrasted. It is suggested that the Early Cretaceous stratigraphic sediments were reserved below Cenozoic strata which belong to Pingyangzheng rift valley of Jixi Basin, Qihulin rift valley and Xingkaihu rift valley of Hulin Basin.7. Owing to earthquake references, we make sure that structure character of Jixi Basin, Boli Basin, Hulin Basin and Hegang Basin. Combining with strata sequences of basins, it is suggested that Jixi Basin and Hulin Basin are multiple basins, and Boli Basin and Hegang Basin are mainly Early Cretaceous remnants basins. 8. According to the study on the 5 regional unconformity in Mesozoic and Cenozoic, it is clear that Dunmi Fault control the basin. The Fault sinistral slide and cut the eastern basins, then formed the huge angle unconformity between Dongshan Formation and Houshigou Formation. Late Cretaceous, eastern basin was destroyed again with the Huanan Upheaval formed. Dunmi Fault dextral slide formed a series of string of beads basins. It is not only formed huge thickness sediment, but also the strata sediment of Early Cretaceous. They are main oil and gas perspective strata.9. According to the study on the basin formed regional background, the destroy by Dunmi Fault and character of strata distribulations, it is suggested that eastern basin was composit basin. It is offered the evidence for oil and gas perspective.10. Study on the regional structure background of basins in Mesozoic and Cenozoic. Make sure the Dunmi Fault control the Jixi Basin, Boli Basin and Hulin Basin. It was sinistral slide Early Cretaceous. In Paleogene, it changed to dextral slide, and formed a series of string of beads basins. The strata of Hulin Formation formed in Paleogene. The Fault function again in Pliocene. It formed a big scale of basalt spew and basalt mesa. Discussed the basic character of basins and Jixi Basin, Boli Basin and Hulin Basin, revealed coal-contained basins in the east suffed the 3 times structure reverse. The basin was destroyed and alterationed. On the base of the alteration of basin, it was controled by Dunmi fault and formed rift valley in Cenozoic. It was sedimented the strata of Palogene and it has the character of composit basin.