Presentation held at the session 1.4 "Quaternary geomorphological systems in a changing climate and environment" at the Mid-European Geomorphology Meeting (MGM) 2021 in Munich, 2021-11-07.
Eastern South Africa is well known for a range of geomorphological archives, such as aeolian beach deposits, peatlands, crater lake sediments, etc. The Masotcheni Fm. is a widespread colluvial phenomenon in the Drakensberg foothills, a region that is highly susceptible to environmental changes and geomorphic response. This makes the Masotcheni not only a valuable record of the last glacial cycle, also with a high relevance for archaeological research, but also a hotspot of modern-day anthropogenic land degradation.We present results from our field work in the Drakensberg Mountains of KwaZulu-Natal, where we studied both the development of the Masotcheni as well as recent gully erosion with a range of techniques. We mapped the spatial distribution of the Formation through an approach comprising mineral remote sensing, geomorphometry and GIS modelling. The stratigraphic sequence was assessed with sediment probes, OSL-Dating, Electric Resistivity Imaging and hyperspectral field spectroscopy. Furthermore, we analyzed recent gully erosion rates with remote sensing by a combination of historical aerial imagery and modern UAV. These information also feed a physical-based numerical gully erosion model, that is currently developed.
Thereafter, the different layers of the Masotcheni Fm. testify multiple cyclic changes of landscape stability, where phases of instability caused the deposition of eroded raw material from the upper slopes. During phases of stability, different types of soils formed within the colluvium and created sequences, that give insight to complex formation processes and past environmental change. Although land degradation, mainly through sheet wash and gully erosion has affected the Masotcheni throughout the Late Pleistocene, erosion of massive gully systems has increased in recent years. Our ongoing research draws focus on the initiation of this phase and takes multiple potential drivers into consideration, including climate anomalies, Late Iron Age population dynamics as well as more recent Land Use / Land Cover Change.
Eastern South Africa is well known for a range of geomorphological archives, such as aeolian beach deposits, peatlands, crater lake sediments, etc. The Masotcheni Fm. is a widespread colluvial phenomenon in the Drakensberg foothills, a region that is highly susceptible to environmental changes and geomorphic response. This makes the Masotcheni not only a valuable record of the last glacial cycle, also with a high relevance for archaeological research, but also a hotspot of modern-day anthropogenic land degradation.We present results from our field work in the Drakensberg Mountains of KwaZulu-Natal, where we studied both the development of the Masotcheni as well as recent gully erosion with a range of techniques. We mapped the spatial distribution of the Formation through an approach comprising mineral remote sensing, geomorphometry and GIS modelling. The stratigraphic sequence was assessed with sediment probes, OSL-Dating, Electric Resistivity Imaging and hyperspectral field spectroscopy. Furthermore, we analyzed recent gully erosion rates with remote sensing by a combination of historical aerial imagery and modern UAV. These information also feed a physical-based numerical gully erosion model, that is currently developed.
Thereafter, the different layers of the Masotcheni Fm. testify multiple cyclic changes of landscape stability, where phases of instability caused the deposition of eroded raw material from the upper slopes. During phases of stability, different types of soils formed within the colluvium and created sequences, that give insight to complex formation processes and past environmental change. Although land degradation, mainly through sheet wash and gully erosion has affected the Masotcheni throughout the Late Pleistocene, erosion of massive gully systems has increased in recent years. Our ongoing research draws focus on the initiation of this phase and takes multiple potential drivers into consideration, including climate anomalies, Late Iron Age population dynamics as well as more recent Land Use / Land Cover Change.