Separating the relative roles of tectonics and climate change in geological evolution is complicated. The northern coast of Bohai Bay (NCBB), with a thick accumulation of Quaternary lacustrine sediments, is a subsiding area and is well suited to studying tectonic versus climatic controls on sedimentary processes. We used magnetostratigraphy and sedimentological analyses of borehole core JL01 from the NCBB to provide new insights into the effects of tectonic processes and climate changes in this region. The results show the following: (1) A shallow lacustrine delta, a deep-water lacustrine sedimentary system and a subaqueous fan-delta sedimentary system developed during 2.1–1.4 Ma, 1.4–0.78 Ma, and from 0.78 Ma to the present, respectively, corresponding to the rift-initiation, rift-climax, and late-rift tectonic stages of the evolution of an extensional basin, respectively. These stages constitute a low-order tectono-sedimentary cycle. (2) Tectonic and orbital-scale climate changes can be distinguished, particularly the 2.5 Ma climatic transition and a significant shift from 41- to 100-kyr cyclicity across the Mid-Pleistocene climatic transition. These changes indicate that the sedimentary processes of the NCBB were influenced by high-latitude climate forcing since the Late Pliocene. Our results demonstrate that detailed sedimentary facies analyses can provide valuable information about the effects of tectonics and climate changes on basin sedimentary evolution. This approach can be applied to other regional basins worldwide.

中文翻译：

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构造和高纬度气候对渤海湾北岸第四纪沉积过程的控制

区分地质构造和气候变化在地质演化中的相对作用是很复杂的。渤海湾北岸（NCBB）有厚厚的第四纪湖泊沉积物堆积，是一个沉降区，非常适合研究构造与气候对沉积过程的控制。我们利用 NCBB 钻孔岩心 JL01 的磁性地层学和沉积学分析，为该地区构造过程和气候变化的影响提供了新的见解。结果表明：（1）2.1~1.4 Ma、1.4~0.78 Ma、0.78 Ma至今分别发育浅水湖相三角洲、深水湖相沉积体系和水下扇三角洲沉积体系。 ，分别对应拉张盆地演化的裂谷起始、裂谷高潮和裂谷晚期构造阶段。这些阶段构成了低阶构造-沉积旋回。 (2) 可以区分构造和轨道尺度的气候变化，特别是 2.5 Ma 气候转变和中更新世气候转变从 41-kyr 到 100-kyr 周期的显着转变。这些变化表明NCBB的沉积过程受到上新世晚期以来高纬度气候强迫的影响。我们的结果表明，详细的沉积相分析可以提供有关构造和气候变化对盆地沉积演化影响的有价值的信息。该方法可应用于全球其他区域盆地。