## 1 Introduction  
The evolution of cycloststratigraphyy commenced with [PERSON]'s theory of climate driven by Earth's orbital cycles at the beginning of the 20 th century. This theory elucidated that cyclical variations in eccentricity, the angle of intersection of the yellow and red angles, and age differences govern the cyclotaxy of the ice ages [1, 2]. This theory was empirically confirmed in 1982 by the [PERSON] team through the study of oxygen isotopes in deep-sea sediments, demonstrating the pivotal role of orbital parameters in controlling ice sheet advances and retreats as well as sea-level fluctuations [3]. In the 1990s, [PERSON] reconstructed the evolution of the Earth-Moon orbital dynamics over 500 million years using fossil corals, elucidating the dynamical linkages between obliquity and the Earth-Sun distance and providing a novel method for geological dating [4]. At the beginning of the 21 st century, the [PERSON] team developed a high-precision solar system orbital model, confirming the super-stability of the 405 kyr eccentricity cycle and reducing the error in the Mesozoic orbital calculations to within 0.2%, thus establishing the 'astronomical ruler' for geological time calibration [5; 6]. In 2013, the [PERSON] team innovatively coupled sedimentary cyclicity analysis with astronomical cycles, developing sub-orbital precision astronomical tuning techniques that expanded the discipline's applications from stratigraphic dating to paleoclimate reconstruction and comparative planetary climatology [7]. The Zhujiangkou Basin is situated in the Cenozoic basin on the continental margin in the northern part of the South China Sea. It is abundant in oil and gas resources, primarily concentrated in the upper section of the Early Eocene Zhujiang Formation, which exhibits significant exploration potential [8; 9]. As oil and gas exploration and development in this basin have progressed, the demand for precise chronost stratigraphic division has increased. In recent years, cyclost stratigraphy has demonstrated extensive application value and scientific significance in the study of the Zhujiangkou Basin. Through spectral analysis and wavelet transformation of natural gamma-ray logging data, researchers have identified Milankovitch cycle signals and established high-resolution astronomical timescales, significantly improving the precision of stratigraphic division and correlation. For example, [PERSON] et al. calibrated the sedimentation duration of the Hanjiang Formation-Wanshan Formation to the 0.1 Ma level using short eccentricity cycles, revealing the correlation between sedimentation rates and sea-level changes [10]. [PERSON] et al. combined biost stratigraphic frameworks to construct an absolute astronomical timescale for the Hanjiang Formation in the Lufeng Sag, providing an independent constraint for estimating the duration of carbon isotope events [11]. Additionally, astronomical cycles have been used to analyze the evolution of sedimentary environments. [PERSON] et al. revealed the spatiotemporal evolution patterns of deltaic sedimentary microfacies by examining the response relationship between the sandstone volume fraction and sea-level changes, confirming the control of astronomical drivers on sedimentary processes [12]. These studies have not only deepened the understanding of the chronost stratigraphy and paleoclimate evolution of the South China Sea during the Cenozoic but also provided theoretical support for reservoir prediction in oil and gas exploration. Most existing studies focus on the independent effects of individual orbital parameters, leaving a theoretical gap in understanding the coupling mechanisms of multiple cycles and their cascading effects. Quantifying the synergistic control mechanisms of astronomical orbital cycles on the 'climate-source-sedimentation' system remains a challenge.