| Summary: | According to Milankovich′s theory, astronomical forces influence the Earth′s climate change, and the sedimentary process records this change. According to Milankovich′s theory, cycles can be identified and separated, which is a powerful complement to traditional sequence stratigraphy. It has a high-level time and month implementation, which can realize high-resolution periodic identification and the establishment of high-precision isochronous stratigraphic framework. The Mosuowan area is one of the favorable areas for oil and gas exploration in the Junggar Basin. Among them, the first section of the Sangonghe Formation has developed effective and large-scale tight gas reservoirs. Using natural gamma log data, through frequency spectrum analysis and other methods, Milankovich signal identification and period division were performed on the target layer in the study area. Based on the 405 ka periodic filtering curve, a floating astronomical scale based on the geological age at the bottom boundary of the Sangonghe Formation is established.Studies have shown that there is a Milankovich′s cycle in the first section of the Sangonghe Formation. The short-term eccentricity 125 ka period controls the cycle with a thickness of approximately 29.73 m; the slope 54 ka period controls the cycle with a thickness of approximately 12.47 m; the precession 24 ka cycle controls the thickness with a cycle of approximately 5.62 m. The geological age of the first section of the Sangonghe Formation is about 189.951-190.800 Ma. A total of seven short-term base-level cycles have been identified, and seven fifth-order sequences have been divided. "Small-increasing-continuously decreasing-continuously increasing" trend, but the overall change is not large. There are three types of short-term datum cycle: B1, B2, and C1.This article details the Milankovich′s cycle identification process and the establishment of astronomical scales, providing a reference and basis for the high-resolution cycle division of the study area.
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