Geology and Resource Potential of the Congo Basin

445 Pages·2015·55.862 MB·English

by  Maarten J. de Wit, François Guillocheau, Michiel C. J. de Wit (eds.)

Regional Geology Reviews
Maarten J. de Wit · François Guillocheau
Michiel C.J. de Wit Editors
Geology and
Resource
Potential of the
Congo Basin
Regional Geology Reviews
SeriesEditors
RolandOberha¨nsli
MaartenJ.deWit
Franc¸oisM.Roure
More information about this series at
http://www.springer.com/series/8643
.
Maarten J. de Wit (cid:129) Franc¸ois Guillocheau (cid:129)
Michiel C.J. de Wit
Editors
Geology and Resource
Potential of the Congo Basin
Editors
MaartenJ.deWit Franc¸oisGuillocheau
AEON-AfricaEarthObservatory Geosciences
Network,andESSRI-Earth UniversityofRennes
StewardshipScienceResearchInstitute RennesCedex
NelsonMandelaMetropolitanUniversity France
PortElizabeth
SouthAfrica
MichielC.J.deWit
Geology
UniversityofPretoria
Pretoria
SouthAfrica
ISBN978-3-642-29481-5 ISBN978-3-642-29482-2(eBook)
DOI10.1007/978-3-642-29482-2
SpringerHeidelbergNewYorkDordrechtLondon
LibraryofCongressControlNumber:2014959861
#Springer-VerlagBerlinHeidelberg2015
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Coverillustration:PhotobyEdmondThorose
Aerialview(helicopterflyingatca.150maboveground)lookingnortheastacrossthesouthwesternCongoBasin,215km
southwestofKinshasa,withoutliersofpoorlyconsolidatedredsandstonesoftheKwangoGroup(Jurassic-Cretaceous)
capped by a subhorizontal hardpan of Cenozoic silcrete. These outliers represent the nothernmost remnants of the
KalahariPlateau,regionalpeneplanationsurface(“theAfricanSurface”)thatiswellpreservedatca.1000macross
southernAfrica.
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Dedication
Our Congobook isdedicated tothree remarkable earth scientists whose work
overaspanofnearly65years,pre-andpost-independentSub-SaharanAfrica,
changed the course of knowledge about the geography, geology, and natural
resources of the Congo Basin and surrounding regions of Central Africa:
Lucien CAHEN (Belgium, 1912–1982), Norman Snelling (England, b.
1930), and Henri KAMPUNZU (DRC—Democratic Republic of Congo,
1952–2004)
Lucien Cahen Norman Snelling Henri Kampunzu
CahenandSnellingwererelativelyshieldedfromthechallengingsociopolitical
and economic issues associated with colonial activities and the inevitable
transitiontoAfricanindependence.Theywereabletofocusmostlyonwhatthey
loved: field geology and figuring out stratigraphy and tectonics using the early
emergence of radiometric dating. By contrast, Kampunzu was a child of the
African struggle for independence; he represented part of a new generation of
Africanscientistsfreedfromcolonialsuppression.Hetoolovedgeologyandits
history, and the field work needed to unravel its complexities, but he was also
‘caughtup’intheturbulentperiodsoftransformationfromtheBelgianCongoto
the Democratic Republic of Congo—DRC. Yet these three scientists formed a
commonbondthroughtheirscientificobservations,curiosity,andwritings,and
thefactthattheyknewthattheywerebuildingontheshouldersofalonglineof
fine, dedicated geoscientists with a love for Africa and its challenges.
The work by these three outstanding geoscientists has left a solid foundation
for a modern analysis of the geology of central Africa. We hope thatthis book
will go some way towards expressing our appreciation and recognition for
their dedicated work.
.
Preface
Thisbookisacollection ofscientificnarrativesabouttheoriginandevolutionoftheCongo
Basinanditssurroundingregions.
TheCongoBasinisavastnearcircularareaofnearly3.7km2,some300–400mabovesea
levelastridetheCongoRiver;itissurroundedbyelevatedregionsandflankedintheeastby
the African Rift System where, in places, elevations of Precambrian rocks and active
volcanoes stand above 5,000 m; and in the west by the Atlantic Ocean into which the
Congo River delivers vast volumes of detritus and dissolved loads (Fig. 1). The Congo
River is the most powerful river in Africa: during the rainy seasons over 50,000 m3 (near
2 million ft3) of water per second flow into the Atlantic Ocean.1 ‘The force with which the
CongoRiveremptiesintotheAtlanticissogreatthatitchangesthecolouroftheseawaterfor
hundredsofkilometersaround’(VanReybrouck2010,2014).Belowsealevel,gravity-driven
currents and suspended sand clouds have carved an immense submarine canyon across the
Fig.1 ImageoftheCongoBasinandsurroundingregionscoveredinthisbook.Thinblackoutlinemarksthe
edgeoftheCongodrainagesystem.Notethattheperspectiveforthehorizontalscalebarduetothe‘depth’and
orientationoftheimage(theimageismorediamondshapethansquare)iscorrectonlynearthecentreofthe
image(i.e.thekmdistancebetweentheCongoRiverarciswithin10%[100km]accuracy).However,forthe
areasaroundtheEastAfricanLakeDistrictandneartheAtlanticcoasttheaccuracyisclosertowithin20%.
Notealsotheverticalexaggeration(figurecourtesyofTyrelFlugel).SeeChaps.14and15inthisbookfor
locationnamesandgreaterinformationaboutthelandscapesandriversystems
1The Congo’s discharge at its mouth ranges from 23,000 cubic metres per second (810,000 cu ft/s) to
75,000m3/s(2,600,000cuft/s).ForamoredetailedaccountoftheCongoBasindrainagesystem,seeChap.
15inthisBook.
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