| Abstrakt: |
In this study, ALOS-PALSAR DEM has been used along with field investigation data to map geological lineaments and analyze the paleostress in the Bikélélé iron deposit. The methodology involved three approaches: manual extraction of lineaments based on visual interpretation by using four shaded relief images through ArcMap v.10.8 software, and stress inversion and slip tendency methods computed in the Win-Tensor program. The resulting lineament map from manual extraction showed that NW–SE, NE–SW, E–W, and N–S trending are the dominant directions of geological structures. These results were confirmed by field investigation data and were well correlated with previous regional studies. The paleostress reconstruction and analysis indicated the existence of two stress fields that were linked to two deformation phases. The first stress field corresponds to the first deformation phase, D1, which involved NW–SW compression and NE–SW extension. This first deformation, D1, resulted in the formation of NW–SE to N–S sinistral fractures and E–W dextral fractures. This phase also developed N–S to E–W foliations and F1 folds. The second stress field was linked to the second phase of deformation, D2. This latter is characterized by NNE–SSW compression and WNW–ESE extension, that formed N–S dextral fractures, NE–SW to E–W sinistral fractures as well as F2 folds. The deformation phase D2 is associated with the Eburnean orogeny, which affected the Archean basement across the Central Africa. The model summarizing these geological structures and the associated deformation phases has been presented. |
Full text from SpringerLink