Study of High-Resolution Sequence of Jurassic Yanan Formation in the East of Ning Xia Province
|School||Shandong University of Science and Technology|
|Course||Paleontology and stratigraphy|
|Keywords||Ningdong Yan'an Formation High resolution sequence stratigraphy Base level cycle Sedimentary facies|
The use of high-resolution sequence stratigraphy theory and methods , the full collection and collation of drilling cores , well logs information of the the Ningdong Yan'an group analysis and depositional systems division of the sedimentary characteristics of the system . Studies show that the Yan'an group goes through from the bottom to the meandering river depositional system - delta sedimentary system - meandering river depositional system , reflecting the Ordos Basin heyday developmental stages . Concentrating on the identification and comparison of high - resolution sequence boundaries of the study area Yan'an group analysis of high resolution sequence stratigraphic division and internal unit , the identification and comparison of the base-level cycle , to identify the short-period cycles in cycle cycle long-period cycles and long cycle cycle four, carved out of a long cycle cycles , four long-period cycles , 11 cycles cycles , as well as multiple short-period cycles . The study found that the long cycle of base-level cycles basin tectonic activity , the region can be correlated , in the cycle of base-level cycles influenced by local topography and source supply , local contrast . Also explore the Yan'an Formation high - resolution sequence stratigraphic framework of the study area, the sedimentary facies characteristics , the study found , the district sedimentary facies was EW , mainly by the sandy river skeleton , the silty river diffuse and muddy swamp , and provide good conditions for the development of the coal seam , the seam accumulation law by the accommodation space to increase or decrease the supply of provenance .