Geomorphology analysis reveales past drainage pathways
Geomorphology is an often undervalued part in exploration studies, yet it can provide a wealth of information and is crucial for the reconstruction of not only drainage patterns but also patterns of erosion and denudation, in turn providing info on total eroded volumes.
A systematic analysis of geomorphology and high-resolution drainage lines was carried out for the S2SMoz study, to detect anomalies that are indicative of past changes in the geometry of the drainage network, of past changes in erosion rates, while also offering clues towards understanding why the changes happened, placing the observations in a larger framework. These are of particular importance for the more recent drainage development, e.g. those post-dating the Oligocene. Also patterns of more ancient surface dynamics can, however, be detected, and some modern landforms serve as analogues for past situations.
For this study, we looked in detail at signs of drainage basin expansion, headward erosion, stream piracy, sites of incision and capture, the geomorphologic expression of competent lithologies and their effect on drainage distribution, the effect of active vs inactive faults, and the development of drainage within incipient to structurally mature rift systems and active structural settings.
The modern land surface is a snapshot of the ever-changing shape of the land surfave, and is the interface between endogenic (tectonics) and exogenic (climate) forces that act upon it.
Read more on palaeodrainage and geomorphologic methods in this GeolSoc publication: Bonne (2014).