Abstract:

The commonly used sea-level curve recovery methods are mainly based on the cyclic analysis and isotopic measurement of stratigraphic sedimentation. These methods are greatly affected negatively by the incompleteness of stratigraphic data, resulting in unreasonable recovery results. In view of this, a global sea-level curve recovery method based on stratigraphic sedimentary inversion is proposed. Based on the fact that the global sea-level cycle has good corresponding relationships with astronomical and sedimentary cycles as multi-scale, multi-level cycles, this method uses trigonometric Fourier series expansion to transform the sea-level change curve, which can greatly smooth out the sea-level curve in stratigraphic sedimentary inversion. Only seven parameters are needed in the new method to characterize sea-level changes in the Haq sea-level curve, demonstrating its applicability. The global sea-level curve of the Changxing Period in the Yuanba area is obtained by stratigraphic sedimentary simulation, which yields more information on the sea-level change, and the recovered sea-level change is more reasonable compared to the Haq sea-level curve and the sea-level change curve of Fischer for the same period. Thus, Fourier series-functionalized sea-level change curve is useful not only in quantification and functionalization of sea-level change, but also in stratigraphic sedimentary inversion to obtain sea-level change curve. Compared with the traditional sea-level change recovery method, this new idea of measuring sea-level change has higher level of quantification, lower requirements for input data, and better applicability and wider application prospect. The application prospect is also discussed.

Key words: stratigraphic inverse modeling, astronomical cycle, Fourier transform, stratigraphic forward modeling, global sea-level change