Neogene cratonic erosion fluxes and landform evolution processes from regional regolith mapping (Burkina Faso, West Africa)

Jean Louis Grimaud, Dominique Chardon, Václav Metelka, Anicet Beauvais, Ousmane Bamba

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

The regionally correlated and dated regolith-paleolandform sequence of Sub-Saharan West Africa offers a unique opportunity to constrain continental-scale regolith dynamics as the key part of the sediment routing system. In this study, a regolith mapping protocol is developed and applied at the scale of Southwestern Burkina Faso. Mapping combines field survey and remote sensing data to reconstruct the topography of the last pediplain that formed over West Africa in the Early and Mid-Miocene (24-11Ma). The nature and preservation pattern of the pediplain are controlled by the spatial variation of bedrock lithology and are partitioned among large drainage basins. Quantification of pediplain dissection and drainage growth allows definition of a cratonic background denudation rate of 2m/My and a minimum characteristic timescale of 20Ma for shield resurfacing. These results may be used to simulate minimum export fluxes of drainage basins of constrained size over geological timescales. Background cratonic denudation results in a clastic export flux of ~4t/km2/year, which is limited by low denudation efficiency of slope processes and correlatively high regolith storage capacity of tropical shields. These salient characteristics of shields' surface dynamics would tend to smooth the riverine export fluxes of shields through geological time.

Original languageEnglish (US)
Pages (from-to)315-330
Number of pages16
JournalGeomorphology
Volume241
DOIs
StatePublished - Jul 5 2015

Fingerprint

landform evolution
regolith
Neogene
shield
denudation
erosion
drainage basin
timescale
geological time
dissection
routing
field survey
bedrock
lithology
spatial variation
Miocene
topography
drainage
remote sensing
West Africa

Keywords

  • Landform evolution processes
  • Pediment
  • Regolith
  • Sediment routing system
  • Source to sink

Cite this

Neogene cratonic erosion fluxes and landform evolution processes from regional regolith mapping (Burkina Faso, West Africa). / Grimaud, Jean Louis; Chardon, Dominique; Metelka, Václav; Beauvais, Anicet; Bamba, Ousmane.

In: Geomorphology, Vol. 241, 05.07.2015, p. 315-330.

Research output: Contribution to journalArticle

Grimaud, Jean Louis ; Chardon, Dominique ; Metelka, Václav ; Beauvais, Anicet ; Bamba, Ousmane. / Neogene cratonic erosion fluxes and landform evolution processes from regional regolith mapping (Burkina Faso, West Africa). In: Geomorphology. 2015 ; Vol. 241. pp. 315-330.
@article{963b0d6cc30044c48ab578286c996140,
title = "Neogene cratonic erosion fluxes and landform evolution processes from regional regolith mapping (Burkina Faso, West Africa)",
abstract = "The regionally correlated and dated regolith-paleolandform sequence of Sub-Saharan West Africa offers a unique opportunity to constrain continental-scale regolith dynamics as the key part of the sediment routing system. In this study, a regolith mapping protocol is developed and applied at the scale of Southwestern Burkina Faso. Mapping combines field survey and remote sensing data to reconstruct the topography of the last pediplain that formed over West Africa in the Early and Mid-Miocene (24-11Ma). The nature and preservation pattern of the pediplain are controlled by the spatial variation of bedrock lithology and are partitioned among large drainage basins. Quantification of pediplain dissection and drainage growth allows definition of a cratonic background denudation rate of 2m/My and a minimum characteristic timescale of 20Ma for shield resurfacing. These results may be used to simulate minimum export fluxes of drainage basins of constrained size over geological timescales. Background cratonic denudation results in a clastic export flux of ~4t/km2/year, which is limited by low denudation efficiency of slope processes and correlatively high regolith storage capacity of tropical shields. These salient characteristics of shields' surface dynamics would tend to smooth the riverine export fluxes of shields through geological time.",
keywords = "Landform evolution processes, Pediment, Regolith, Sediment routing system, Source to sink",
author = "Grimaud, {Jean Louis} and Dominique Chardon and V{\'a}clav Metelka and Anicet Beauvais and Ousmane Bamba",
year = "2015",
month = "7",
day = "5",
doi = "10.1016/j.geomorph.2015.04.006",
language = "English (US)",
volume = "241",
pages = "315--330",
journal = "Geomorphology",
issn = "0169-555X",
publisher = "Elsevier",

}

TY - JOUR

T1 - Neogene cratonic erosion fluxes and landform evolution processes from regional regolith mapping (Burkina Faso, West Africa)

AU - Grimaud, Jean Louis

AU - Chardon, Dominique

AU - Metelka, Václav

AU - Beauvais, Anicet

AU - Bamba, Ousmane

PY - 2015/7/5

Y1 - 2015/7/5

N2 - The regionally correlated and dated regolith-paleolandform sequence of Sub-Saharan West Africa offers a unique opportunity to constrain continental-scale regolith dynamics as the key part of the sediment routing system. In this study, a regolith mapping protocol is developed and applied at the scale of Southwestern Burkina Faso. Mapping combines field survey and remote sensing data to reconstruct the topography of the last pediplain that formed over West Africa in the Early and Mid-Miocene (24-11Ma). The nature and preservation pattern of the pediplain are controlled by the spatial variation of bedrock lithology and are partitioned among large drainage basins. Quantification of pediplain dissection and drainage growth allows definition of a cratonic background denudation rate of 2m/My and a minimum characteristic timescale of 20Ma for shield resurfacing. These results may be used to simulate minimum export fluxes of drainage basins of constrained size over geological timescales. Background cratonic denudation results in a clastic export flux of ~4t/km2/year, which is limited by low denudation efficiency of slope processes and correlatively high regolith storage capacity of tropical shields. These salient characteristics of shields' surface dynamics would tend to smooth the riverine export fluxes of shields through geological time.

AB - The regionally correlated and dated regolith-paleolandform sequence of Sub-Saharan West Africa offers a unique opportunity to constrain continental-scale regolith dynamics as the key part of the sediment routing system. In this study, a regolith mapping protocol is developed and applied at the scale of Southwestern Burkina Faso. Mapping combines field survey and remote sensing data to reconstruct the topography of the last pediplain that formed over West Africa in the Early and Mid-Miocene (24-11Ma). The nature and preservation pattern of the pediplain are controlled by the spatial variation of bedrock lithology and are partitioned among large drainage basins. Quantification of pediplain dissection and drainage growth allows definition of a cratonic background denudation rate of 2m/My and a minimum characteristic timescale of 20Ma for shield resurfacing. These results may be used to simulate minimum export fluxes of drainage basins of constrained size over geological timescales. Background cratonic denudation results in a clastic export flux of ~4t/km2/year, which is limited by low denudation efficiency of slope processes and correlatively high regolith storage capacity of tropical shields. These salient characteristics of shields' surface dynamics would tend to smooth the riverine export fluxes of shields through geological time.

KW - Landform evolution processes

KW - Pediment

KW - Regolith

KW - Sediment routing system

KW - Source to sink

UR - http://www.scopus.com/inward/record.url?scp=84928693870&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84928693870&partnerID=8YFLogxK

U2 - 10.1016/j.geomorph.2015.04.006

DO - 10.1016/j.geomorph.2015.04.006

M3 - Article

AN - SCOPUS:84928693870

VL - 241

SP - 315

EP - 330

JO - Geomorphology

JF - Geomorphology

SN - 0169-555X

ER -