The African landscape through space and time
File(s)
Published version
Author(s)
Paul, JD
Roberts, GG
White, N
Type
Journal Article
Abstract
It is generally accepted that Cenozoic epeirogeny of the African continent is moderated by convective circulation of the mantle. Nevertheless, the spatial and temporal evolution of Africa's “basin-and-swell” physiography is not well known. Here we show how continental drainage networks can be used to place broad constraints on the pattern of uplift through space and time. First, we assemble an inventory of 710 longitudinal river profiles that includes major tributaries of the 10 largest catchments. River profiles have been jointly inverted to determine the pattern of uplift rate as a function of space and time. Our inverse model assumes that shapes of river profiles are controlled by uplift rate history and modulated by erosional processes, which can be calibrated using independent geologic evidence (e.g., marine terraces, volcanism and thermochronologic data). Our results suggest that modern African topography started to develop ∼30 Myr ago when volcanic swells appeared in North and East Africa. During the last 15–20 Myr, subequatorial Africa was rapidly elevated, culminating in the appearance of three large swells that straddle southern and western coasts. Our results enable patterns of sedimentary flux at major deltas to be predicted and tested. We suggest that the evolution of drainage networks is dominated by rapid upstream advection of signals produced by a changing pattern of regional uplift. An important corollary is that, with careful independent calibration, these networks might act as useful tape recorders of otherwise inaccessible mantle processes. Finally, we note that there are substantial discrepancies between our results and published dynamic topographic predictions.
Date Issued
2014-06-03
Date Acceptance
2014-04-24
Citation
Tectonics, 2014, 33 (6), pp.898-935
ISSN
0278-7407
Publisher
American Geophysical Union
Start Page
898
End Page
935
Journal / Book Title
Tectonics
Volume
33
Issue
6
Copyright Statement
© 2014 American Geophysical Union. All Rights Reserved. An edited version of this paper was published by AGU. Paul, J. D., G. G. Roberts, and N. White (2014), The African landscape through space and time, Tectonics, 32, 898–935, doi:10.1002/2013TC003479. To view the published open abstract, go to: https://dx.doi.org/10.1002/2013TC003479
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000340248700002&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Physical Sciences
Geochemistry & Geophysics
GEOCHEMISTRY & GEOPHYSICS
FISSION-TRACK THERMOCHRONOLOGY
SOUTH-AFRICA
CONTINENTAL-MARGIN
MANTLE CONVECTION
EAST-AFRICA
LONGITUDINAL PROFILES
ENVIRONMENTAL-CHANGE
SOUTHWESTERN AFRICA
DENUDATION HISTORY
CHANNEL PROFILES
0403 Geology
0404 Geophysics
Publication Status
Published