The topographic evolution of southern Africa: reconnaissance of a pathway through a precarious and rugged conceptual landscape
Prof. Rod Brown from the University of Glasgow, Scotland is visting the department next week. He will stay with us whole week. Rod is a thermochronologist. He has done quite a lot of work in Africa, especially in South-Africa, Namibia and Mozambique. Rod has accepted to give a seminar next thursday. You are all welcome to join in the Auditorium 5, from 12:15.
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The topographic evolution of southern Africa: reconnaissance of a pathway
through a precarious and rugged conceptual landscape
Some of the most influential literature and ideas on how continental topography is formed and evolves over geological time originated from work in southern Africa. Much of this was by contemporaries of Alfred Wegner in the early 20th century: Walther Penck, William Davis, and perhaps Wegener’s strongest supporter, the South African geologist, Alex du Toit.
The most prolific and enduring work is probably that of Lester King who followed these pioneers and championed the concept of the formation of extensive, low relief land surfaces or “pediments” by a process he called “pediplanation”. This idea directly challenged the other dominant paradigm of “peneplanation” promoted by William Davis. After more than 100 years the controversial debate and intellectual wrangling over how fast, when and why the topography of this continent evolved to produce the classic present escarpment morphology still rages–even more vigorously than ever it seems.
The resurgence in interest has arguably been stoked, not by field geomorphology, but by major advances in seismology and geodynamic and surface process modelling capacity and sophistication. This work has focused on the properties and behaviour of the deep mantle beneath southern Africa and whether the mantle has anything at all to do with Africa’s unusually high topography. If anything, this has caused even more dissent and argument though.
This seminar will attempt to highlight the “common ground”, so to speak, between opposing ideas, and where there may be opportunities to resolve the key points of difference between opposing hypotheses.
Romain Beucher