Department of Earth Science, Aarhus University, DK-8000 Aarhus C, Denmark.
Science. 2010 Aug 13;329(5993):827-30. doi: 10.1126/science.1190115.
Cyclic sedimentary deposits link stratigraphic sequences that are now geographically distant but were once part of the same depositional environment. Some of these sequences occur at periods of 2 to 20 million years, and eustatic sea-level variations or regional tectonic events are likely causes of their formation. Using numerical modeling, we demonstrate that small-scale mantle convection can also cause the development of stratigraphic sequences through recurrent local and regional vertical surface movements. Small-scale convection-driven stratigraphic sequences occur at periods of 2 to 20 million years and correlate only at distances up to a few hundred kilometers. These results suggest that previous sequence stratigraphic analyses may contain erroneous conclusions regarding eustatic sea-level variations.
旋回沉积层将在地理上相距甚远但曾经处于同一沉积环境的地层序列联系起来。其中一些地层序列发生在 200 万至 2000 万年的时间内,海平面的整体升降或区域构造事件可能是其形成的原因。通过数值模拟,我们证明小规模的地幔对流也可以通过反复的局部和区域垂直地表运动来导致地层序列的发育。小规模的对流驱动的地层序列发生在 200 万至 2000 万年的时间内,并且仅在几百公里的范围内相关。这些结果表明,先前的层序地层分析可能包含关于海平面整体升降的错误结论。