Continental Evolution: The Geology of Morocco: Structure, Stratigraphy, and Tectonics of the Africa-Atlantic-Mediterranean Triple Junction (Lecture Notes in Earth Sciences)

438 Pages·2008·98.7 MB·English

by  André Michard

Lecture Notes in Earth Sciences 116
Editor:
S.Bhattacharji,Brooklyn
H.J.Neugebauer,Bonn
J.Reitner,Göttingen
K.Stüwe,Graz
FoundingEditors:
G.M.Friedman,BrooklynandTroy
A.Seilacher,TübingenandYale
Frontispiece:Dicranurusmonstrusus(LowerPragian),J.Issimour(Maider,EasternAnti-Atlas).
CourtesyM.Ihmadi(IhmadiTrilobiteCenter,Alnif,Morocco)
· ·
André Michard Omar Saddiqi
·
Ahmed Chalouan
Dominique Frizon de Lamotte (Eds.)
Continental
Evolution: The
Geology of Morocco
Structure, Stratigraphy, and Tectonics
of the Africa-Atlantic-Mediterranean
Triple Junction
With235ColorFigures
123
Editors
Prof.Dr.AndréMichard Prof.Dr.OmarSaddiqi
10ruedesJeuˆneurs AinChockUniversity
75002Paris FacultyofSciences
France B.P.5366Maaˆrif
[email protected] Casablanca
Morocco
[email protected]
Prof.Dr.AhmedChalouan Prof.Dr.DominiqueFrizondeLamotte
MohammedV-AgdalUniversity UniversitéCergy-Pontoise
avenueIbnBatouta DépartementSciencesdela
Rabat Terre
B.P.1014 SitedeNeuville
Morocco 95031Cergy
[email protected] France
[email protected]
ForallLectureNotesinEarthSciencespublishedtillnowpleaseseefinalpagesofthebook
ISBN:978-3-540-77075-6 e-ISBN:978-3-540-77076-3
LectureNotesinEarthSciencesISSN:0930-0317
LibraryofCongressControlNumber:2008932115
(cid:2)c 2008Springer-VerlagBerlinHeidelberg
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Prefaces
PrefacefromHerExcellencytheMinisterofEnergy,Mines,
WaterandEnvironment,DirectorofONHYM
Due to its geological diversity, related to the succession of four geological cycles
fromtheArcheantotheAlpineOrogeny,andincludingthemajorPan-Africanand
Variscancycles,Moroccohasalwaysbeencharacterizedbyintenseminingactivity.
TheearliestminingworksincludetheremainsofexploitationsatImiter(Ag),Bleida
(Cu),Zgounder(Ag),Iourirn(Au),Tazalaght(Cu)andhavebeendatedfromthe9th
to15thcenturies.Today,Moroccoistheworld’sleadingexporterforphosphatesand
producessignificantquantitiesofawidevarietyofmineralresourcessuchassilver,
zinc,lead,cobalt,manganese,fluorite,barite,bentonite,etc.
The development of the Earth Sciences in Morocco undergone a surge of new
activityduringthelasttwodecades,basedonthediversityofitssubstratumandon
the international achievements in this domain. This new impulse resulted in high
levelresearchprogramsintheframeofnationalandinternationalpartnerships,and
inthelaunchingoftheNationalPlanforGeologicalMappingaimedatprovidinga
geologicalinfrastructuretothecountry,andincludinggeological,geophysicaland
geochemicalmapping.Thisintenseactivityresultedinabetterunderstandingofthe
geodynamicframework,basedonamoreprecisestratigraphyandonthesystematic
use of seismic profiles, geophysical modelling experiments, and modern geotech-
nologiessuchasSHRIMPisotopicdatingsandfissiontrackthermochronology.
It is precisely within this context that the work entitled Continental Evolution:
GeologyofMoroccoispresentedbyPr.A.Michardandaninternational,multidis-
ciplinaryteam.Thisworkfollowsanearlierbookpublishedbythesameauthorin
1976 under the title “Ele´ments de Ge´ologie Marocaine”. As a specialist in tecton-
ics, Pr. Michard is familiar with Moroccan geology. Since the early 70’s, he has
participated in the education of a number of Moroccan geologists, and today he
continues to supervise theses and co-author papers on the geology of the country.
In fact, two of his co-editors and several of his co-authors are former students of
v
vi Prefaces
him.Pr.MichardalsosupervisesthemappingactivityofgeologistsoftheMinistry
ofEnergy,Mines,WaterandtheEnvironment.
This new book provides an updated overview of the geological knowledge of
Morocco based on the achievements of the last few decades. The authors pay
homagetotheirpredecessor’sworkwithalargesetofreferencesprovidingacom-
pletereviewandinsightintothegeologyofMorocco.Afteranoutlineofthegeolog-
ical structure and evolution of the country, in the context of the African continent
and peri-Atlantic plate tectonics, the book considers successively the Pan-African
Beltwitharefinedgeodynamicinterpretation;theVariscaneventsintheAnti-Atlas
andsouthernMoroccoaswellasintheMesetaDomain;theAtlasSystem,RifBelt,
Atlantic Basins and Mesetan and Saharan Plateaus, all of which developed during
theAlpinecycle;andfinallytheQuaternarydeposits.
WeareconvincedthatthisworkwillstrengthenthepositionofMoroccangeol-
ogyintheinternationalcommunityofgeosciences.Thisbookconstitutesessential
readingforoperatorsinthesectorsofmines,petroleumandtheenvironment.Italso
provides key insights into the major problems of continental crust evolution from
theArcheantothePresent.
Prepared by a multi-disciplinary team of specialists in teaching and transfer of
knowledge,thisworkwillbecomethestandardworkforfuturegenerationsofgeo-
scientistsseekingtounderstandthegeologyofMorocco.
Wewarmlycongratulatetheentireteamofexpertswhoundertooktherealization
ofthiswork,andhopetoseeitdistributedwidelyinMoroccoandelsewhere.
AminaBenkhadra
PrefacefromtheInternationalLithosphereProgram
MoroccoconstitutesauniquenaturallaboratoryatthejunctionbetweentheAtlantic
margin, the Mediterranean and the African craton. There, long lastinginteractions
betweenmantleandlithospheredynamics,crustalextensionandcompression,sub-
sidence and uplift, can be documented in great detail using surface geological
recordspreservedinsynrift,postriftandforelandsedimentaryseries.Outcropsare
excellentintheinvertedbasinsoftheAtlas,whereasmostlowlandsandtheoffshore
are covered by industry seismic profiles, which have been calibrated by numerous
explorationwells.
InOctober2007,thegeologyofMoroccohasattractedtheinterestofmorethan
700 geologists coming from its conjugate margins in Canada and the US, from
Spain, France and other European countries, as well as from other North African
countries,alltheseearthscientistsconveningforaninternationalmeetinghostedby
the MAPG, with a strong participation of the ILP Task force VI on Sedimentary
Basins.
Morocco has become the focus of discussion for both the academic and indus-
try international communities, which will strongly benefit from this updated com-
pilation of the Moroccan geology. This new Springer volume, co-authored by 36
Prefaces vii
contributors from various Moroccan (Rabat, Casablanca, Ke´nitra and Marrakech)
and European (Orsay, Cergy-Pontoise, Montpellier, Savoie, Toulouse, ENS-Paris,
African Museum of Belgium, Neuchaˆtel, Granada) universities and the industry
(ONHYM and OMV), comprises 10 chapters dedicated to the main geodynamic
episodes which controlled the geology of the country, from the Precambrian and
Paleozoic orogens to the Mesozoic rifting and subsequent episodes of basin in-
version. We are grateful to the editors, Andre´ Michard and Dominique Frizon de
Lamotteononehand,andOmarSaddiqiandAhmedChalouanontheotherhand,
who are respectively two leading French and Moroccan experts of the geology of
this part of the World, for having stimulated the contributions of such wide range
ofexpertise,andtoprovidetheinternationalcommunitywithaveryhighstandard,
easytoreadvolume.
∗ ∗∗ ∗∗
SierdCloetingh ,Franc¸oisRoure andMagdalenaScheck-Wenderoth
∗ ∗∗
ILPPresident.- ILPTaskForceVIonSedimentaryBasins
PrefacefromtheSocie´te´ Ge´ologiquedeFrance
Moroccoisthekeypointbetweenonepassivemargin(AtlanticOcean),oneocean
actingtoclosure(Mediterranean)andanoldcraton(Africa).ShowingPrecambrian
and Palaeozoic orogenies up to Mesozoic rifting and Cenozoic orogeny, Morocco
isafantasticplacewheregeodynamicinteractionsbetweenmantleandlithosphere
areillustrated.
Inthisremarkablebookwhichperfectlyresumesthelastdiscoveriesandstateof
knowledgeofMoroccogeology,Andre´ Michard,OmarSaddiqi,AhmedChalouan
and Dominique Frizon de Lamotte, together with a wide panel of specialists, are
offering us the “field verity” that is tosay, the results of observation and cartogra-
physynthesis.Thesediscoveriesandstateofknowledgehavebeenexposedinthe
October 2007 International Congress of Marrakech organized by MAPG and ILP,
and followed by seven hundreds people coming from either academic or profes-
sionalworld.Theauthorsandcontributorsofthepresentbookweretheleadersof
mostofthefieldtripsrelatedtothecongress.
SincethetimeofthepioneersofthegeologicaldiscoveryofMorocco(A.Brives,
L. Gentil, L. Neltner and others), the Socie´te´ ge´ologique de France has published
hundredsofpapersandanumberofmemoirsconcerningthegeology,paleontology
or mineralogy of Morocco, and its Bulletin remains one of the traditional tribunes
for Moroccan publications. Let us also recall the “Re´union Extraordinaire” of the
SGFatRabat,1973,dedicatedtotheGibraltarArc.
Today, it is a great honour for the Socie´te´ ge´ologique de France to support the
publicationanddiffusionofsuchaveryhighstandardvolume.
ChristianRavenneandAndre´ Schaaf
PresidentandFirstVice-PresidentoftheSocie´te´ Ge´ologiquedeFrance
Foreword and Acknowledgements
“Thescholarisnotaforeignerinanyforeigncountry[...].
Culture,whereverwego,accompaniesus,guidesus,and
allowsustoarrivesafeandsound.”
BartolomeoPlatina,Defalsoetverobono(1460)
TheideaofanewoverviewofMoroccangeologyoriginatedfromanearlyprojectin
November2005ofaguidebookrelatedtotheeducationalprogramoftheEcoleNor-
maleSupe´rieure (ENS,Paris)and the University of Cergy-Pontoise. During 2006,
wereceivedsubstantialmoralandlogisticsupportfromtheMoroccanAssociation
ofPetroleumGeologists(MAPG),andbytheOfficeNationaldesHydrocarbureset
desMines(ONHYM),inrelationtothepreparationforthe1stMAPGInternational
ConventionandExhibitionthatwasheldinMarrakech,Oct.2007.
WhilepreparingtheMAPGfieldtripprogram,wedecidedtoundertakeasurvey
of the geological evolution of Morocco to be published as an independent work,
in addition to the field trip guide books. The Socie´te´ ge´ologique de France (SGF)
immediately agreed to consider some sort of co-edition of a future “Geology of
Morocco”,andMichelFaure,Editor-in-ChiefoftheBulletinoftheSGForganized
apeerreviewingprocessofthesuccessivechapters(Dec.2006).Anearlydraftofthe
book,nowentitled:ContinentalEvolution:TheGeologyofMorocco,wasreadyfor
submissiontoSpringerVerlaginJuly2007.Thelastmonthsof2007weredevoted
toimprovethetextandillustrationsbasedonthecriticalreviewsreceivedfromthe
numerouscolleaguesandspecialiststhatwehadsolicited.
Producingthisbookwasateameffortinvolvingmanypeople.Weareallindebted
to our predecessors who investigated Moroccan geology for nearly a century. We
areparticularlyindebtedtothosegeoscientists,fromMoroccoandelsewhere,who,
duringthelastthreedecades,broughtourunderstandingofMoroccouptomodern,
internationalstandards.
Wewanttothankourcolleaguesfromvariousuniversitiesandinstitutionswho
shared with us their knowledge of the subject and/or of the English language
by reviewing our chapters: S. Bogdanoff, R. Bortz, J.-P. Bouillin, J. Destombes,
M.Durand-Delga,M.Faure,R.Maury,F.Medina,T.Pharaoh,B.Purser,F.Roure,
S. Samson, J.-P. Schaer, J. F. Simancas, J. I. Soto, A. Tahiri, Tan Say Biow,
J.-C.Trichet.
ix
x ForewordandAcknowledgements
Warm thanks are also due to the colleagues who allowed us to use the origi-
nal files of many valuable illustrations: D. Aslanian, A. Baltzer, M. Ben Abbou,
late M. Burkhard, I. Contrucci, J. Destombes, H. Echarfaoui, E.H.El Arabi, H. El
Hadi, A. El Harfi, J. Fabre, J. Fullea Urchulutegui, R. Guiraud, M.-A. Gutscher,
H. Haddoumi, M. R. Houari, M. Ihmadi, H. Jabour, K.B. Knight, P. Krzywiec,
E. Laville, N. Loget, A. Maillard, H. Ouanaimi, G. Rosenbaum, D. Rumsey, M.
Sahabi, F. Sani, A. Schettino, J. F. Simancas, W. Spakman, G. Stampfli, D. Stich,
A.Teixell,E.Teson.WeacknowledgetheauthorizationsbythecorrespondingPub-
lisherstousefreelytheseillustrations.
We acknowledge the moral and material support received from our academic
institutions, in particular the ENS (Paris), and the Universities of Casablanca-A¨ın
Chock, Cergy-Pontoise, and Rabat; from the CNRS-INSU (“Relief de la Terre”
Program) and the French-Moroccan “Action Inte´gre´e” Volubilis; from the MAPG
and ONHYM in Morocco, particularly to A. Morabet and A. Mouttaqi; and from
the SGF in Paris, particularly to F. Rangin, M. Faure, P. de Wever and A. Schaaf.
We thank B. El Ilam (ONHYM, Rabat) and A. Paillet (EDYTEM, Chambe´ry) for
their help in the drawing of many figures. Finally, the support of the International
LithosphereProgram(ILP)andtheMinistryofEnergy,Mines,WaterResourcesand
EnvironmentofMorocco(MEM)arealsogratefullyacknowledged.
Obviously,thepresentworkpresentsonlyasmallpartofwhatcanbeseeninthe
area.Wehopethatitwillprovidethereaderwithanupdatedinsightofthegeology
ofthiscountry,andhopefullystimulatenewstudiesintheverynearfuture.
A.Michard,O.Saddiqi,A.Chalouan,andD.FrizondeLamotte