Abstract The Dongying Formation (Ed) and the first member of the Shahejie Formation (Es1) in the central Raoyang Sag cover about 1705 m-long sedimentary series of terrestrial lacustrine infill. We employed the gamma-ray (GR) log data as a paleoclimatic and paleoenvironmental proxy to conduct the high-resolution cyclostratigraphy research in well W33 and W62. Prominent sedimentary cycles in decameters and meters were revealed by multi-taper (MTM) power spectra, evolutionary fast Flourier transformation (FFT) and correlation coefficient analyses in the Es1 and Ed intervals. The 405 kyr long eccentricity, 125 kyr and 100 kyr short eccentricity, 40 kyr obliquity, and 23 kyr precession can be recognized with a wavelength ratio of approximately 20:5:2:1, respectively. By tuning the 405 kyr filter output in well W33 to the orbital target curve of La2010d astronomical solution, we established an astronomical time scale (ATS) that provided absolute age controls during the Oligocene and shed light on the event correlation among isolated depressions in the Bohai Bay Basin. Sediment accumulation rates (SARs) were derived from the extracted 405 kyr long eccentricity and were tested with an average of 17 cm/kyr. Age boundaries of Ng/Ed1, Ed1/Ed2, Ed2/Ed3, Ed3/Es1 and Es1/Es2 are 23.03 Ma, 24.34 Ma, 25.53 Ma, 29.05 Ma and 33.10 Ma, respectively. Based on the ATS and SARs, we discussed the depositional evolution within age boundaries, cause of high SARs and origin of formation overpressure. After the largest lake transgression, shallow-water deltas and fluvial plains transitionally dominate the central Raoyang Sag with shallowing water depth. Thin interlayers of mudstones and sandstones originate from shallow-water deltaic systems with low sand-to-mud ratios. Under high SARs enhanced by mountain uplift and low sand-to-mud ratios, formation overpressure results mainly from high porosities in under-compacted mudstone intervals.

中文翻译：

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渤海湾盆地冀中坳陷渐新世旋回地层与天文调谐

摘要 饶阳凹陷中部东营组(Ed)和沙河街组第一段(Es1)覆盖了约1705 m长的陆相湖相充填沉积系列。我们采用伽马射线 (GR) 测井数据作为古气候和古环境代理，在 W33 和 W62 井中进行高分辨率旋回地层学研究。通过多锥 (MTM) 功率谱、进化快速 Flourier 变换 (FFT) 和 Es1 和 Ed 区间的相关系数分析揭示了以十米和米为单位的突出沉积旋回。405 kyr 长偏心、125 kyr 和100 kyr 短偏心率、40 kyr 倾角和23 kyr 进动可以分别以大约20:5:2:1 的波长比识别。通过将 W33 井的 405 kyr 滤波器输出调整到 La2010d 天文解的轨道目标曲线，我们建立了一个天文时间尺度 (ATS)，它提供了渐新世期间的绝对年龄控制，并揭示了渤海孤立凹陷之间的事件相关性湾盆地。沉积物积累率 (SAR) 来自提取的 405 kyr 长偏心率，并以 17 cm/kyr 的平均值进行测试。Ng/Ed1、Ed1/Ed2、Ed2/Ed3、Ed3/Es1和Es1/Es2的年龄界限分别为23.03 Ma、24.34 Ma、25.53 Ma、29.05 Ma和33.10 Ma。基于ATS和SARs，我们讨论了年龄边界内的沉积演化、高SARs的成因和地层超压的成因。在最大的湖泊海侵之后，饶阳凹陷中部以浅水三角洲和河流平原过渡为主，水深变浅。泥岩和砂岩的薄夹层起源于具有低砂泥比的浅水三角洲系统。在山地抬升和低砂泥比增强的高SARs下，地层超压主要来自欠压实泥岩层段的高孔隙度。