Reconstruction of denuded stratigraphic paleosurfaces of diverse folds based on structural element feature constraints

Reconstructing the stratigraphic paleosurfaces of a fold is essential for deciphering the folding mechanism, simulating landscape evolution processes, and investigating mineral resource distribution. However, standard methods for reconstructing paleosurfaces in tectonic landforms, primarily applied on large-scale sedimentary basins and orogenic belts, heavily rely on extensive geological data and generally yield low-accuracy results. This limits their applicability to small to intermediate-scale geological structural areas. Therefore, this paper introduces a stratigraphic paleosurface reconstruction method tailored for small and intermediate-scale folds, leveraging structural element features to constrain this reconstruction, which is notably helpful when dealing with sparse geological and topographic data. This method involves several steps. Firstly, define the fold units for diverse landforms. Secondly, extract fold structural elements (FSEs) with diverse geological data. Next, fit the paleo-boundary of each stratum within the two-dimensional (2D) cross-section using elemental feature constraints. Finally, the Morphing technique is applied to interpolate multiple paleo-boundaries, which are then utilized in reconstructing the stratigraphic paleosurfaces through the Contour Reconstruction Algorithm (CRA). To validate the method, tests were conducted on three representative folds in China: the eastern Sichuan comb-like fold belt, the Dayueshan Anticline on Mount Lu, and the Wulongshan Dome near the Huangling Dome. Experimental results demonstrate that utilizing structural features as constraints enables automatic, accurate, and reliable stratigraphic paleosurface reconstruction. The reconstructed paleosurfaces facilitate the analysis of geometric characteristics and structural development mechanisms of folds within the study area. Furthermore, they can be readily incorporated into landscape evolution models (i.e., TTLEM) to simulate realistic topographic evolution and tectonic paleogeographic mapping or construct three-dimensional (3D) solid models.