Applied Research in Ichnology and Sedimentology (ARISE) Group, Department of Earth Sciences, Simon Fraser University, Burnaby, Canada.
Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan.
Sci Rep. 2021 Aug 18;11(1):16707. doi: 10.1038/s41598-021-96372-x.
Global marine archives from the early Pleistocene indicate that glacial-interglacial cycles, and their corresponding sea-level cycles, have predominantly a periodicity of ~ 41 kyrs driven by Earth's obliquity. Here, we present a clastic shallow-marine record from the early Pleistocene in Southeast Asia (Cholan Formation, Taiwan). The studied strata comprise stacked cyclic successions deposited in offshore to nearshore environments in the paleo-Taiwan Strait. The stratigraphy was compared to both a δO isotope record of benthic foraminifera and orbital parameters driving insolation at the time of deposition. Analyses indicate a strong correlation between depositional cycles and Northern Hemisphere summer insolation, which is precession-dominated with an obliquity component. Our results represent geological evidence of precession-dominated sea-level fluctuations during the early Pleistocene, independent of a global ice-volume proxy. Preservation of this signal is possible due to the high-accommodation creation and high-sedimentation rate in the basin enhancing the completeness of the stratigraphic record.
全球早更新世海洋档案表明，冰川-间冰期循环及其相应的海平面循环主要具有约 41000 年的周期性，这是由地球倾斜度驱动的。在这里，我们展示了东南亚早更新世的碎屑浅海记录（台湾的乔兰组）。研究的地层由在古台湾海峡近海至近岸环境中沉积的堆叠旋回组成。地层学与当时沉积时的底栖有孔虫 δO 同位素记录和驱动太阳辐射的轨道参数进行了比较。分析表明，沉积旋回与北半球夏季太阳辐射之间存在很强的相关性，这主要是由岁差控制的，并有倾斜分量。我们的结果代表了早更新世期间由岁差控制的海平面波动的地质证据，与全球冰量代理无关。由于盆地中高容空间的产生和高沉积速率增强了地层记录的完整性，因此保存了这一信号。
