FAN Q Q, ZHENG D S, SUN F B ,et al.Identification of Milankovitch cycles and reconstruction of Earth-Moon system：A case study of the middle-upper members in the Dagushi Formation on the southern margin of the North China Craton[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(5):155-165.

doi:10.16186/j.cnki.1673-9787.2025100026

Received:2025/10/02

Revised:2025/12/03

Published:2026-07-24

Identification of Milankovitch cycles and reconstruction of Earth-Moon system：A case study of the middle-upper members in the Dagushi Formation on the southern margin of the North China Craton

Fan Qiongqi, Zheng Deshun, Sun Fengbo, Li Ting

School of Resources and Environment， Henan Polytechnic University， Jiaozuo 454003， Henan， China

Abstract: Objectives This study aimed to identify the Milankovitch cycles in the early Mesoproterozoic （~1 787 Ma） based on cyclostratigraphic evidence， and to calculate the Earth-Moon orbital parameters， including the precession constant k， Earth-Moon distance and day length，to reconstruct the evolutionary history of the deep-time Earth-Moon system.  Methods Using high-resolution Fe and Ti element concentration data from X-ray fluorescence （XRF） analysis as paleoclimate proxies， cyclostratigraphic analysis was performed on the middle-upper Dagushi Formation in the Huangbeijiao section， southern margin of the North China Craton， to identify the main astronomical cycles of the early Mesoproterozoic. Due to the lack of accurate radioisotope age constraints， the sedimentation rate could not be precisely estimated from chronostratigraphic data and formation thickness. To improve the reliability of the cyclostratigraphic interpretation， two methods—the correlation coefficient （COCO）and the time scale optimization （TimeOpt）—were employed to estimate the average sedimentation rate of the studied strata. Furthermore， Earth-Moon orbital parameters were estimated via two independent methods：k+s₃ method and Bayesian inversion （TimeOptMCMC）.  Results The average sedimentation rate for the studied strata is estimated to be 2.36~2.53 cm/ka. Spectral analysis reveals that the dominant sedimentary cycles of 10.150 m，2.200~2.210 m， 0.427~0.436 m，and 0.279~0.355 m correspond to the orbital 405 ka long eccentricity， 86.50~87.00 ka short eccentricity，16.48~17.28 ka obliquity，and 13.08~14.09 ka precession cycles， respectively. The k+s₃ approach yielded a precession constant k of 95.8±1.1 arcsec/a， an Earth-Moon distance of 330 783（+937/-926） km， and a day length of 17.86 （+0.09/-0.08）h， while the TimeOptMCMC approach yielded a precession constant k of 92.21±1.6 arcsec/a， an Earth-Moon distance of 333 885 （+1 426/-1 398） km， and a day length of 18.14（+0.14/-0.12） h.  Conclusions Significant Milankovitch cycle signals were recorded in the Dagushi Formation in the Huangbeijiao section，confirming that the sedimentary records in the early Mesoproterozoic Era（~1 787 Ma）were controlled by Milankovitch cycles. The Earth-Moon parameters derived from these two independent methods provide new evidence for understanding the evolutionary history of the Earth-Moon system during the early Mesoproterozoic.

Key words:cyclostratigraphy;Huangbeijiao section;Dagushi Formation;Earth-Moon system;southern margin of the North China Craton