The Formation and Evolution of Africa: A Synopsis of 3.8 Ga of Earth History (Geological Society Special Publication 357)

386 Pages·2011·17.16 MB·English

by  D J J van Hinsbergen

The Formation and Evolution of Africa: A Synopsis of
3.8 Ga of Earth History
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VANHINSBERGEN,D.J.J.,BUITER,S.J.H.,TORSVIK,T.H.,GAINA,C.&WEBB,S.J.(eds)2011.The
FormationandEvolutionofAfrica:ASynopsisof3.8GaofEarthHistory.GeologicalSociety,London,
SpecialPublications,357.
LETTS,S.,TORSVIK,T.H.,WEBB,S.J.&ASHWAL,L.D.2011.NewPaleoproterozoicpalaeomagnetic
datafromtheKaapvaalCraton,SouthAfrica.In:VANHINSBERGEN,D.J.J.,BUITER,S.J.H.,TORSVIK,
T.H.,GAINA, C. & WEBB,S.J.(eds)TheFormationandEvolutionofAfrica:ASynopsisof3.8Gaof
EarthHistory.GeologicalSociety,London,SpecialPublications,357,9–26.
GEOLOGICAL SOCIETY SPECIAL PUBLICATION NO.357
The Formation and Evolution of Africa: A Synopsis of
3.8 Ga of Earth History
EDITED BY
D. J. J. VAN HINSBERGEN
University of Oslo, Norway
S. J. H. BUITER
Geological Survey of Norway
T. H. TORSVIK
Universityof Oslo
C. GAINA
Geological Survey of Norway
and
S. J. WEBB
Universityof the Witwatersrand, SouthAfrica
2011
Published by
The Geological Society
London
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Contents
VANHINSBERGEN,D.J.J.,BUITER,S.J.H.,TORSVIK,T.H.,GAINA,C.&WEBB,S.J.Theformationand 1
evolutionofAfricafromtheArchaeantoPresent:introduction
LETTS,S.,TORSVIK,T.H.,WEBB,S.J.&ASHWAL,L.D.NewPalaeoproterozoicpalaeomagneticdata 9
fromtheKaapvaalCraton,SouthAfrica
VANSCHIJNDEL,V.,CORNELL,D.H.,HOFFMANN,K.-H.&FREI,D.Threeepisodesofcrustal 27
developmentintheRehobothProvince,Namibia
KEY,R.M.,PITFIELD,P.E.J.,THOMAS,R.J.,GOODENOUGH,K.M.,DEWAELE,B.,SCHOFIELD,D.I., 49
BAUER,W.,HORSTWOOD,M.S.A.,STYLES,M.T.,CONRAD,J.,ENCARNACION,J.,LIDKE,D.J.,
O’CONNOR,E.A.,POTTER,C.,SMITH,R.A.,WALSH,G.J.,RALISON,A.V.,RANDRIAMANANJARA,T.,
RAFAHATELO,J.-M.&RABARIMANANA,M.PolyphaseNeoproterozoicorogenesiswithintheEast
Africa–AntarcticaOrogenicBeltincentralandnorthernMadagascar
WENDORFF,M.TectonosedimentaryexpressionsoftheevolutionoftheFungurumeforelandbasinin 69
theLufilianArc,Neoproterozoic–LowerPalaeozoic,CentralAfrica
DEWALL,H.,DIETL,C.,JUNGMANN,O.,TEGENE,A.T.&PANDIT,M.K.Tectonicevolutionofthe 85
CentralSteepZone,Axumarea,northernEthiopia:inferencesfrommagneticandgeochemicaldata
LONGRIDGE,L.,GIBSON,R.L.,KINNAIRD,J.A.&ARMSTRONG,R.A.Constrainingthetimingof 107
deformationinthesouthwesternCentralZoneoftheDamaraBelt,Namibia
TORSVIK,T.H.&COCKS,L.R.M.ThePalaeozoicpalaeogeographyofcentralGondwana 137
ELHACHIMI,H.,YOUBI,N.,MADEIRA,J.,BENSALAH,M.K.,MARTINS,L.,MATA,J.,MEDINA,F., 167
BERTRAND,H.,MARZOLI,A.,MUNHA´,J.,BELLIENI,G.,MAHMOUDI,A.,ABBOU,M.B.&ASSAFAR,H.
Morphology,internalarchitectureandemplacementmechanismsoflavaflowsfromtheCentral
AtlanticMagmaticProvince(CAMP)ofArganaBasin(Morocco)
DEENEN,M.,LANGEREIS,C.,KRIJGSMAN,W.,ELHACHIMI,H.&CHELLAI,E.H.Palaeomagneticresults 195
fromUpperTriassicred-bedsandCAMPlavasoftheArganaBasin,Morocco
RUIZ-MART´INEZ,V.C.,PALENCIA-ORTAS,A.,VILLALAI´N,J.J.,MCINTOSH,G.&MARTI´N-HERNA´NDEZ,F. 211
PalaeomagneticandAMSstudyoftheTarfayacoastalbasin,Morocco:anearlyTuronianpalaeopole
fortheAfricanplate
GANERØD,M.,TORSVIK,T.H.,VANHINSBERGEN,D.J.J.,GAINA,C.,CORFU,F.,WERNER,S., 229
OWEN-SMITH,T.M.,ASHWAL,L.D.,WEBB,S.J.&HENDRIKS,B.W.H.Palaeopositionofthe
SeychellesmicrocontinentinrelationtotheDeccanTrapsandthePlumeGenerationZoneinLate
Cretaceous–EarlyPalaeogenetime
AYALEW,D.Therelationsbetweenfelsicandmaficvolcanicrocksincontinentalfloodbasaltsof 253
Ethiopia:implicationforthethermalweakeningofthecrust
ENDRESS,C.,FURMAN,T.,EL-RUS,M.A.A.&HANAN,B.B.Geochemistryof24Mabasaltsfrom 265
NEEgypt:sourcecomponentsandfractionationhistory
WICHURA,H.,BOUSQUET,R.,OBERHA¨NSLI,R.,STRECKER,M.R.&TRAUTH,M.H.TheMid-Miocene 285
EastAfricanPlateau:apre-rifttopographicmodelinferredfromtheemplacementofthephonolitic
Yattalavaflow,Kenya
vi CONTENTS
MAHANEY,W.C.,BARENDREGT,R.W.,VILLENEUVE,M.,DOSTAL,J.,HAMILTON,T.S.&MILNER,M.W. 301
LateNeogenevolcanicsandinterbeddedpalaeosolsnearMountKenya
CAPITANIO,F.A.,FACCENNA,C.,FUNICIELLO,R.&SALVINI,F.RecenttectonicsofTripolitania,Libya: 319
anintraplaterecordofMediterraneansubduction
BRAITENBERG,C.,MARIANI,P.,EBBING,J.&SPRLAK,M.TheenigmaticChadlineamentrevisitedwith 329
globalgravityandgravity-gradientfields
FISHWICK,S.&BASTOW,I.D.TowardsabetterunderstandingofAfricantopography:areviewof 343
passive-sourceseismicstudiesoftheAfricancrustanduppermantle
Index 373
The formation and evolution of Africa from the Archaean to Present:
introduction
DOUWEJ.J.VANHINSBERGEN1,2*,SUSANNEJ.H.BUITER1,2,3,TROND
H.TORSVIK1,2,3,4,CARMENGAINA1,2,3&SUSANJ.WEBB4
1PhysicsofGeologicalProcesses,UniversityofOslo,SemSælandsvei24,
NO-0316Oslo,Norway
2CenterforAdvancedStudy,NorwegianAcademyofScienceandLetters,
Drammensveien78,0271Oslo,Norway
3CentreforGeodynamics,GeologicalSurveyofNorway(NGU),LeivEirikssonsvei39,
7491Trondheim,Norway
4SchoolofGeosciences,UniversityoftheWitwatersrand,WITS2050Johannesburg,
SouthAfrica
*Correspondingauthor(e-mail:[email protected])
The African continent preserves a long geological Thisspecialvolumecontains18originalcontri-
record that covers almost 75% of Earth’s history. butions about the geology of Africa. It celebrates
ThePan-Africanorogeny(c.600–500Ma)brought African geology in two ways. First, it celebrates
together old continental kernels (or cratonssuch as multidisciplinaryEarthScienceresearch,highlight-
West African, Congo, Kalahari and Tanzania) ingtheformationandevolutionofAfricafrom18
formingGondwanaandsubsequentlythesuperconti- different angles. Second, this volume celebrates
nentPangeabythelatePalaeozoic(Fig.1). the work of Kevin Burke and Lewis Ashwal. We
The break-up of Pangea since the Jurassic and hopethatthis‘BurkeandAshwal’volumeportrays
Cretaceous, primarily through the opening of the thewiderangeofinterestsandresearchanglesthat
Central Atlantic (e.g. Torsvik et al. 2008; Labails have characterized these two scientists throughout
etal.2010),Indian(e.g.Gainaetal.2007;Mu¨ller their careers working in Africa and studying
etal.2008;Candeetal.2010)andSouthAtlantic African geology (Ashwal & Burke 1989; Burke
(e.g. Torsvik et al. 2009) oceans and the compli- 1996;Burkeetal.2003).
cated subduction history to the north gradually
shaped the African continent and its surrounding
oceanic basins. Many first-order questions of Contentofthevolume
African geology are still unanswered. How many
accretionphasesdotheProterozoicbeltsrepresent? ThisvolumefocusesontheformationofAfricaasa
What triggers extension and formation of the East coherentcontinent, fromthe formationofsomeof
African Rift on a continent that is largely sur- the oldest continental crust known today in the
rounded by spreading centres and, therefore, KaapvaalCraton(deWitetal.1992)tobillionsof
expected to be mainly in compression? What is years of collisions and arc-accretions, amalgamat-
theroleofshallowmantleandedge-drivenconvec- ing these old continental fragments (Hoffman
tion(King&Ritsema2000)?Whatarethesources 1991;Stern1994;Zhaoetal.2002;Torsvik2003)
of the volcanic centres of Northern Africa (e.g. into Gondwana and the supercontinent Pangea.
Tibesti,DafurandAfar)andcantheybetracedto Thecontributionsinthisvolumecovermostofthe
the lower mantle? Is the elevation of Eastern and African continent (Fig. 2), span .2Ga of its
Southern Africa caused by mantle processes? history and approach its complex history from a
What is the formation mechanism of intracratonic geophysical, geological,geochemicaland physical
sedimentarybasins,suchastheTaoudeniBasinon geographicalpointofview.
the West African Craton and the Congo Basin In recent years, the importance of deep mantle
(e.g. Hartley & Allen 1994; Giresse 2005)? How processesasatriggerforsurfacevolcanisminclud-
do sedimentation and tectonics interact (Burke & ing world-changing (?) Large Igneous Province
Gunnell 2008)? Can we reconstruct this elevation emplacement (Burke & Torsvik 2004; Burke
and its impact on climate evolution (e.g. Wichura etal.2008),diamond-bearingkimberliteformation
etal.2011)? (Torsvik et al. 2010) and dynamic topography
From:VanHinsbergen,D.J.J.,Buiter,S.J.H.,Torsvik,T.H.,Gaina,C.&Webb,S.J.(eds)TheFormation
andEvolutionofAfrica:ASynopsisof3.8GaofEarthHistory.GeologicalSociety,London,SpecialPublications,
357,1–8. DOI:10.1144/SP357.1 0305-8719/11/$15.00#TheGeologicalSocietyofLondon2011.
2 D.J.J.VANHINSBERGENETAL.
Fig.1. AgeofAfricancrustalbasement(afterGubanov&Mooney2009).Theagesarethetimeofcrustalformationor
thetimeofthermalortectoniccrustalreworking.
(e.g.Lithgow-Bertollini&Silver1998)hasbecome Letts et al. (2011) provide new, high-quality
evident. Several contributions in this volume shed palaeomagnetic poles for c. 2Ga old rocks from
new light on these processes and their geological the Kaapvaal Craton. By comparing their new
andenvironmentaleffects. results with published information, they demon-
stratethattheKaapvaalCratonwasnotassociated
with high rates of apparent polar wander during
Part1:ThemakingoftheAfricancrust:The the c. 2.1–1.9Ga interval. Van Schijndel et al.
Archaean–Palaeozoicphases (2011)providenewdetritalzircondatafromsand-
stones in the Rehoboth province of Namibia that
The first part of this volume covers the formation identify three dominant periods of continental
of Africa from old cratons through assembly crust formation: between 1.3–1.1, 2.0–1.8 and
in the Pan-African orogeny to the formation of 3–2.7Ga, the latter of which was previously
Gondwana. unknown. Key et al. (2011) report an extensive
INTRODUCTION 3
Fishwick & Bastow
El Hachimi et al.
Deenen et al. Capitanio et al. Endress et al.
Ruiz-Martinez et al.
Ayelew et al.De Wall
Braitenberg et al.
Wichura et al.
Wendorff Mahaney et al. et al.Ganerød
Longridge et al.
van Schijndel et al. Key et al.
Letts et al.
Torsvik & Cocks
Fig.2. Studyareascoveredinthisvolume.
geological surveyof the basement rocks of Mada- of Gondwana between 510 and 250Ma. They
gascar,providinganoverviewofthefiveArchaean detail the locations of passive and active margins
toProterozoicbasementblocksthatarerecognized around Gondwana throughout the Palaeozoic,
ontheisland.TheyreviewtheNeoproterozoiccol- continental shelves, evaporite deposits, volcanism
lisionandamalgamationhistoryoftheMadagascar and glaciations, including those affecting Africa
segment of the East Africa–Antarctica Orogen, andArabia.
which was finalized during the Terminal
Pan-African Event 560–490Ma ago. Wendorff
(2011) provides new insights into the history of Part2:Africasincethebreak-upofPangea:
the Lufilian Arc, which formed as a result of the TheMesozoic–Cenozoicphases
Pan-African collision between the Kalahari and
Congo cratons. The structural and stratigraphic The papers in the second part discuss events from
evolution of this belt shows evidence for two pre- the break-up of Pangea to the late Cenozoic.
viously unidentified rift and foreland basins. De During this time Africa moved relatively slowly
Walletal.(2011)studythe metamorphicandtec- (Burke1996).ElHachimietal.(2011)focustheir
tonichistoryoftheTerminalPan-AfricanEventin attentionontheCentralAtlanticMagmaticProvince
Ethiopia.Theyprovidenewmetamorphicandmag- (CAMP) that was emplaced around 200Ma. The
netic fabric data from the Central Steep Zone, a mantleplumethatledtoitsemplacementprobably
transpressionalbeltthatcanbetracedintoEritrea. triggered Pangea dispersal (Burke & Dewey
Theyarguethatthedeformationandmetamorphism 1973). El Hachimi et al. (2011) study the mor-
in their study area results from closure of the phology, internal architecture and emplacement
Mozambique Ocean and the final assembly of mechanisms of CAMP lavas in the Argana Basin
Gondwana. Longridge et al. (2011) provide a of Morocco. They demonstrate that the emplace-
detailedstructuralgeologicalandgeochronological ment mechanisms are in line with continental
study of the Central Zone of the Pan-African flood basalt facies models. Deenen et al. (2011)
Damara orogen in Namibia. They unravel a take a stratigraphic approach to the CAMP, and
history of crustal thickening, heating of the mid- use magnetostratigraphic and cyclostratigraphic
crust, exhumation and orogen-parallel extension techniques to correlate the Moroccan segment of
between c. 540 and 500Ma. Torsvik & Cocks theCAMPtotheircounterpartsontheNWsideof
(2011) provide nine new palaeogeographic maps the Atlantic Ocean in Canada and the United