The Palaeostream Approach is a geomorphologic workflow developed at Streamstar Geosolutions that enables systematic reconstruction of palaeodrainage evolution, taking into account continent-scale topographic evolution. Using remote sensing and GIS tools, not only analysis of drainage anomalies and pathways is carried out, but also landforms are interpreted, modern analogues for ancient landscapes are provided, and palaeosurfaces and cycles of land surface development and rejuvenation are recognized. The approach is two-fold, allowing for different methods to deal with very ancient to recent palaeodrainage reconstructions. The methodology is given in the reports and can be applied for other regions of the world.
Read more on how this method was applied for the reconstruction of the rivers of the Mozambique Margins.
Some findings and outcomes:
- By applying this method, and studying other passive margins, we found that large river systems draining continental interiors and flowing to passive margins, develop after a given lag-time following break-up, and that they develop at intersections of regional structural belts. This is the case for the Zambezi, Limpopo, Congo, Niger, Volta, Amazon, and other large rivers globally. Shorter rivers at passive margins play an important role in sediment flux to the oceans.
- We study and understand processes such as headward erosion, drainage reversal, stream piracy, stream capture, etc., which happen continuously on medium to large time-scales and are the key processes in driving drainage changes and river evolution.
- We also introduce the new general term of drainage expansion, which refers to one drainage basin becoming larger, irrespective of the causes of the expansion.
Top photo: Kwilu River, DRC. @K.Bonne.