B01 Copertina R OK C August 20-28,2004 Florence -Italy

B01_copertina_R_OK C August 20-28,2004 Florence -Italy

Field Trip Guide Book - B01 Associate Leader:E.O.Abdulsamad Leader: A.S.El-Hawat Pre-Congress NORTH EASTERNLIBYA OF CYRENAICA GEOLOGY ANDARCHEOLOGY 32 Volume n°1-fromPR01toB15 GEOLOGICAL CONGRESS nd INTERNATIONAL B01 28-05-2004, 18:48:52 The scientific content of this guide is under the total responsibility of the Authors

Published by: APAT – Italian Agency for the Environmental Protection and Technical Services - Via Vitaliano Brancati, 48 - 00144 Roma - Italy

Series Editors: Luca Guerrieri, Irene Rischia and Leonello Serva (APAT, Roma)

English Desk-copy Editors: Paul Mazza (Università di Firenze), Jessica Ann Thonn (Università di Firenze), Nathalie Marléne Adams (Università di Firenze), Miriam Friedman (Università di Firenze), Kate Eadie (Freelance indipendent professional)

Field Trip Committee: Leonello Serva (APAT, Roma), Alessandro Michetti (Università dell’Insubria, Como), Giulio Pavia (Università di Torino), Raffaele Pignone (Servizio Geologico Regione Emilia-Romagna, Bologna) and Riccardo Polino (CNR, Torino)

Acknowledgments: The 32nd IGC Organizing Committee is grateful to Roberto Pompili and Elisa Brustia (APAT, Roma) for their collaboration in editing.

Graphic project: Full snc - Firenze

Layout and press: Lito Terrazzi srl - Firenze

B01_copertina_R_OK D 19-05-2004, 17:04:41 Volume n°1 - from PR01 to B15

32nd INTERNATIONAL GEOLOGICAL CONGRESS

THE GEOLOGY AND ARCHAEOLOGY OF CYRENAICA

AUTHORS: A.S. El-Hawat (Garyounis University Benghazi - Libya) E.O. Abdulsamad (Garyounis University Benghazi - Libya)

Florence - Italy August 20-28, 2004

Pre-Congress B01

B01_R_OK A 20-05-2004, 8:50:56 Front Cover: A view at wadi al Athrun mouth sea-cliff exposure showing Maastrichtian chalk slump structure. It is a testament of the ongoing tectonic activities of Cyrenaica due to the compressive forces induced by the conversion of Eurasian and African plates that also led to inversion and development of Al Jabal al Akhdar anticlinorium.

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Leader: A.S. El-Hawat Associate Leader: E.O. Abdulsamad

Introduction hallmarks of the eustatic and inversion tectonic General: Cyrenaica is located in northeastern Libya events that infl uenced the Mediterranean. Sequences and forms a prominent promontory on the North to be examined exhibit a complete spectrum of African coast that covers about 150,000 km2 (Figure carbonate ramp facies complexes that include bathyal 1). It consists of two distinct tectonic provinces planktonic foraminiferal limestone, outer ramp deep separated by a hinge line called the Cyrenaican neritic mudstone clinoforms, and large foraminiferal fault system. These provinces are the mobile north and coralgal-reefal build-ups, as well as oolitic and Cyrenaica inverted basin, referred to as Al Jabal al large foraminiferal shoals, up to the Messinian salina Akhdar; and the more stable Cyrenaica platform to the deposits. The impact of eustatic and tectonic events south (Figure 2). The northern mobile belt area, where on the sedimentary and biostratigraphic history of the fi eldtrip will be conducted, has been infl uenced the succession will be demonstrated and evaluated. by the Tethys tectonic activities and events since its Unconformities, syndepositional mass movements, opening during the Jurassic. It was subsequently and reworking of sediments and fossils together shaped by the reversal of the Eurasian and African with issues of palaeontological versus physical plate movement that led to subduction of the latter stratigraphic boundaries will be discussed in the beneath the former from the Upper Cretaceous to fi eld in light of the geologic and tectonic setting in the present. The goal of the fi eldtrip is to examine Cyrenaica. A visit to the well-preserved ancient city of a complete and gently deformed Cenozoic carbonate Cyrene (631 B.C.), where the fi rst Greek settlers came succession and the associated Upper Cretaceous to North Africa is planned, as well. The geologic and - Paleocene inversion inliers (Figure 3) in a typical hydrogeological factors that led to the establishment southern Tethyan setting. of Cyrene (the place with a hole in the heavens), and In the framework of the history of northern Cyrenaica the history of its destruction by tectonically induced in relation to the Tethys, this fi eld trip will deal seismic events will be a point of interest. with the sedimentology, biostratigraphy and the

Figure 1 - LandSat image of northern Cyrenaica. Volume n° 1 - from PR01 to B15 n° 1 - from Volume

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Volume n° 1 - from PR01 to B15 B01 - B01 Leader: A.S.El-Hawat an introductorylecturewillbegiven. The fi will behousedinoneofBenghazi’s hotels,where After thearrival oftheparticipantsatBenghazithey Logistics: of theregionalcrosssection.(source:ElHawat etal.,inpress.) Figure 2-Locationmapofthetectonicprovinces ofCyrenaicaandlocation larger foraminifera. palaeontology, palaeoecologyandbiostratigraphyof opportunity forspecialiststodiscusstheCenozoic shall alsobedescribed. The areaoffers anexcellent structurally controlledpalaeotopographicsettings sequence indifferent Depositional modelsandsub-modelsofthesame structure of Al Jabalal Akhdar anticlinorium. changes inrelationshiptotheinversion Cretaceous clear understandingofthevertical andlateralfacies visited over thecourseoffi tracing ofthecarbonatesequencesthatshallbe undeformed natureofthesuccessionpermitsaclear Upper CretaceousandCenozoicsuccessions. The back cover) presentwell-exposed andcomplete The new roadcutsandquarriesofCyrenaica(See Transport willbemainlybysmallbuses andvehicles. accessibility toalltheoutcropsinfi an excellent paved roadnetwork thatoffers good will startearlythenext day. Libyaisconnectedby eld trip,enablinga eld triparea. eld trip eld reaches 30to35 August weatherinCyrenaicaishot. Temperature moderate, asmostoutcropsareclosetopaved roads. intensity ofthefi plenty offl use plentyofsunblock. We alsorecommenddrinking Updated in1977bytheSurvey DepartmentofLibya US Army, Washington, D.C.andprintedin1967. by the Army MapService,CorpsofEngineers, 50,000 basedonaerialphotostaken in1964,prepared Topographic mapsofCyrenaica,NELibya,scale 1: 2. TopographicMaps: El Hawat, A.S. and Abdulsamad, E.O.,inpress. The El Hawat. A.S. andShelmani,M.A.,1993.Short 1. Guidebooks: Field References: advised towearfi Science SocietyofLibya, Tripoli. Geology ofCyrenaica: A FieldSeminar. Earth 70 pages. la Akhdar, CyrenaicaNELibya.Interprint,Malta. notes andguidebookonthegeologyof Al Jabal uids, even ifnotthirsty. The physical eld clothes, o C duringtheday. Participants are eld work, however, islightto sun hatsandshades 20-05-2004, 8:47:01 THE GEOLOGY AND ARCHAEOLOGY OF CYRENAICA B01

based on 1:250 000 scale Landsat images. stretches to the east into the Marmarica platform of 3. Geologic maps: the Western Desert of Egypt. South of the inverted Contant, L.C. and Goudarzi, G.H., 1964. Geologic basin of Al Jabal al Akhdar, two elongated Tertiary map of Libya, scale 1:2,000,000. U.S Geol. depositional troughs separate the north from Survey, Map I-350 A. tectonically stable provinces of Cyrenaica to the Francis, M. and Issawi, B., 1977. Geological map south. These are the Marmarica and Ash-Sheliedima of Libya; 1:250,000, Sheet NH 34-2, Soluq, and troughs that dip toward their relative depocenters to explanatory booklet. Ind. Res. Cent., Tripoli, 86 the northeast and southwest respectively along the pp. Cyrenaica fault system. Al Jaghbub High, which forms Geological Map of Libya, scale 1:1,000,000. the southern extension of the Cyrenaica platform, is Industrial Research Center, geological research & separated from the eastern extension of the Sirt basin, mining department, Tripoli, Libya. (1985). which is called the Al Hameimat trough, along the Klen, L., 1974. Geological map of Libya; 1:250, southern Cyrenaica fault system (Figure2). 000. Sheet NI 34-14, Bengahzi, and explan atory booklet. Indust. Resear. Cent., Tripoli, 56 pp. The Al Jabal al Akhdar inverse anticlinorium was Rohlich, P., 1974. Geological map of Libya; 1:250,000 down faulted to form the northern coastal plain, that sheet, Al Bayda sheet NI34-15, explanatory extends into the steep, narrow, and intensely faulted booklet. Indust. Resear. Cent., Tripoli, 70 pp. and folded continental margin offshore. It is separated Zert, B., 1974. Geologic map of Libya, 1:250,000, from the Mediterranean Ridge by a deep, , narrow Dernah sheet NI 34-I6, explanatory booklet. and elongated furrow at 2500 to 3000 meters of Indst. Resear. Cent., Tripoli, 49 pp.0 depth. This represents the line of the noth Cyrenaica fault system (NCFS). Meanwhile, the Cyrenaican Regional geologic setting continental slope to the south, is being differentially General: overthrusted by the Mediterranean Ridge, in what is The Cyrenaican promontory is bound to the west regarded as an incipient continental collision process and south by extensions of the Sirt rift complex and (Huguen and Mascle, 2001). Whereas the northern

Figure 3 - Geological map and cross ections of northern Cyrenaica. (Sources: El Hawat and Shelmani, 1993; Volume n° 1 - from PR01 to B15 n° 1 - from Volume

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Volume n° 1 - from PR01 to B15 B01 - B01 El Hawat et al.,inpress). Figure 6-RegionalgeologiccrosssectionofCyrenaica Sources:ElHawat andShelmani,1993; El Hawat etal.,inpress). ( Sources: Anketell, 1996;HuguenandMuscle,2001; Figure 4-Tectonic provinces ofCyrenaica Leader: A.S.El-Hawat Cretaceous tothepresent. Also, thepresenceofaseries in outcropssectionsrangingagefromtheUpper debris ﬂ throughout time.Majorslumpstructures,slides, unconformities attesttorecurringcompressive events syndepositional massmovements ofsedimentsand part oftheMediterranean.Evidencerepeated repeated andpersistentcompressive events inthis signatures observed innorthernCyrenaicaindicate Cretaceous deformationstructures,stratigraphic Apart fromthepresenceofpost-depositionalUpper to inversion. of maximumsubsidencetheCyrenaicanbasinprior Cretaceous inliers(Figure3),correspondstotheaxis Akhdar runningalongthestructuralaxisofUpper land. The highesttopographicareasof Al Jabalal Mesozoic subsidingbasinofnorthernCyrenaicaon Akhdar anticlinoriumrepresentsaninverted early – Europeanand Aegean plates,the Al Jabalal Ridge duetheconvergence betweenthe African maximum compressive effect oftheMediterranean tip oftheCyrenaicanpromontoryexempliﬁ ows and turbiditesarecommonlyobserved 20-05-2004, 8:47:09 e the es THE GEOLOGY AND ARCHAEOLOGY OF CYRENAICA B01 Volume n° 1 - from PR01 to B15 n° 1 - from Volume

Figure 5 - Stratigraphic chart of northern Cyrenaica (sources: El Hawat et al., in press).

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Volume n° 1 - from PR01 to B15 B01 - B01 Leader: A.S.El-Hawat wrench fault systems(Figure4). Cyrenaica, Cyrenaicaandsoutherndextral a dextral contractional duplex boundbynorthern Jabal al Akhdar inverse anticlinoriumrepresents formed withinasplaywedge.Furthermore,the Al dextral wrenchsetting, theCyrenaicaplatformwas represents apull-apartextensional basinwithina Anketell (1996)postulatedthatwhereastheSirtbasin tectonic analysisofthesedimentarybasinsLibya are evidence ofneotectonicactivities. Inhisrecent earthquakes andpresentlysubmerged alongthecoast well asancientarchaeologicalsitesdestroyed by along thenortherncoastalmargin ofCyrenaica,as of elevated Pleistocenewave-cut erosionalterraces sequence oftheLanghian- Figure 7-StratigraphiclogoftheSoluq-Abyarroadcut,showing outcrop Serravalian, Tortonian andMessiniansuccessions. extension ofthe Al Jabalal Akhdar anticlinorium outcrops showing thepassageof the southern On thefi Field itinerary summarises thegeologicalhistoryofCyrenaica. lithostratigraphic andtectoniccrosssection(Figure6) formation namesandunconformities. The regional successions ofnorthernCyrenaica,completewith stratigraphic chartoftheMesozoicandCenozoic rst dayofthefi Miocene theincreasedcompressive inversion. Second,attheendof phase ofthenorthernCyrenaica lateral wrenchingsetoff theinitial Upper-Cretaceous-to-Miocene right First, compressionforcesinducedby occurred intwo maintectonicphases. the inversion ofnorthernCyrenaica we grouptheseevents wenoticethat Hawat (El Hawat andShelmani,1993;El fi Middle Eocene,Oligoceneand, Santonian, Palaeocene, Lower- inversion pulsesduringthe This was thenfollowed bymajor margin startedduringthe Turonian. deformation ofitscontinental northern Cyrenaicabasinandthe suggests thattheinversion ofthe surface geologicdata,strongly as shown byseismic,drillingand but extensive stratigraphic hiatuses, angular unconformitywithvariable the openingof Tethys. A major Jurassic-Lower Cretaceouswith then acceleratedduringtheMiddle started tobreak-up. The process during the Triassic, whenPangea Cyrenaica basinwas initiated fault anddevelopment ofnorthern that subsidencealongtheCyrenaica Cyrenaica tectonicevents suggests The timingofthenorthern tectonic signatures.Figure5isthe that overprinted theearlierwrench uplifting tectonicsinCyrenaica Ridge causeddominantvertical infl nally, attheendofMiocene uence oftheMediterranean DAY 1 et al eld tripwe’ll stop tosee ., inpress).However, if 20-05-2004, 8:47:17 THE GEOLOGY AND ARCHAEOLOGY OF CYRENAICA B01

Tortonian-Messinian Wadi al Qattarah Formation. , The latter formation is represented by cross-bedded ooskeletal limestone overlain by mudstone and crystalline gypsum facies . Close examination of the unconformity reveals the lithological contrast between the two formations. Also, the sharply-defi ned, bored, burrowed and truncated surface that is followed by transgressive lag dominated by Echinolamps sp shell concentration(Figure 9), forms Figure 8 - View of the outcrop exposed on the opposite side of the Soluq-Abyar the basal transgressive system road cut, showing the clearly defi ned Middle-Upper Miocene boundary. tract of the W. al Qattarah Fm. towards the Sirt rift complex of central Libya. We will A condensed section lies a few then examine outcrops of Middle-Upper Miocene decimetres above the unconformity surface. This rocks, and follow this section into older Neogene and consists of cross-laminated foraminiferal grainstone Palaeogene portions as we go northwards towards the and packstone, capped by a lithifi ed hardground Jabal al Akhdar axis. To do this we will drive south with sponge and Lithophaga borings, and open and from Benghazi towards the village of Soluq and then partially-fi lled burrows. The upper surface of the take a north-easterly road to the town of Abyar. hardground is encrusted with small oysters, serpulids and bryozoa (Figure 10). This CS discontinuity Stop 1: surface is correlatable for up to 60 km northward Starting along the roadcut at the base of Al Jabal along the depositional strike. al Akhdar’s fi rst escarpment we will examine the Walking up the road along the roadcut we will Miocene section where the Middle -Upper Miocene examine the rest of the Tortonian section which is boundary is exposed (Figure 7). The whole section dominated by the ooskeletal shoal facies. These are had been previously ascribed to the Middle Miocene, interrupted at the top by a thick partially-restricted but the discovery of the boundary (El Hawat and lagoonal mudstone facies, and an oolitic limestone Salem, 1985; 1987), which eventually was correlated unit exhibiting soft sediment deformation. with outcrops in central and western Libya (El Hawat In turn, these terms are overlain by a Messinian et al., 1993), led to labelling the upper half of the section as Tortonian and Messinian. The boundary is clearly defi ned on both sides of the roadcut (Figure 8), where it separates shallowing up-cyclesof massive bedded, coarse skeletal limestone of the Langhian-Serravalian Volume n° 1 - from PR01 to B15 n° 1 - from Volume Benghazi Formation from the

Figure 9 - Close-up of the Middle-Upper Miocene unconformity showing a sharply- deﬁ ned bored surface followed by transgressive lag of Echinolamps sp. at the base of the Tortonian.

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Volume n° 1 - from PR01 to B15 B01 - B01 Leader: A.S.El-Hawat of slightly sequence consisting observed atstop1. They formabeltextending 50km of theshallow marinecoarseskeletal bankdeposits 11). The patch reefsarethelandward equivalent Miocene majorerosionalunconformity(Figure These basallayersareseparatedbyaMiddle–Upper well- beddedlagoonallimemudstonewithostracods. Middle MiocenePoritesreefal facies overlain bya Al Abyar. The outcropatthisstopconsistsofmassive are locatedfurthertothenortheastalongroad We arenow atahigheraltitudethanthelaststop,and Stop 2: forms aprominent erosionalunconformity. ostracods-rich, mudstonefacies.Theboundarybetween thetwo units Porites patch reef, followed bywell-bedded UpperMiocene, Figure 11-Elevatedexposureofmassive, bedded,Langhian-Serravalian twinned coarselycrystallinegypsum. into gyps-stromatolitesand,fi gypsarenites thatshift fi a unitofrippled, oysters, overlain by rootlets, anddwarfed of bioturbation,plant sandstone, evidence showing calcareous sand andclayfacies deltaic andestuarine section transitionsinto drive alongtheroad gypsum. After ashort of coarselycrystalline stromatolites, andlenses banks, mudstone,algal with dwarfed oyster channelled unitsofmarl n-rie lagoonal ne-grained folded and nly swallow-tail nally, is attributable toseveral causes.First The presenceofthesereefsathigherelevations Akhdar anticlinoriumduringtheMiddleMiocene. The reefbeltformedarimaroundthe Al Jabalal southward tothewesternmargin oftheSirtriftbasin. northward to Al Abyar, andonehundredkilometres tectonic upliftof Al Jabalal Akhdar andCyrenaica however, weresubsequentlyoverprinted bythe 1987). These palaeotopographicandeustaticcauses, an offl Middle Mioceneseafl Middle Miocene,thentransgressionover thesloping the condensedsection(CS)attopoftransgressive Figure 10-Closeupoftheboredhardgroundforming ap relationship(ElHawat andSalem,1985; system tract(TST)atthebaseofTortonian. issued outfromtheMessinianbasin is furthernorththanthesiliciclastics deposits (Figure12,13). This locality oor inthe Tortonian produced al Miocene (ElHawat peaked attheendof African plate,which subduction oftheNorth forces inducedbythe due tothecompressive carbonate andgypsum Messinian salinalake’s examine a typical quarry weshall At theHawa alBarraq Stop 3: ., inpress). regression inthe 20-05-2004, 8:47:33 et THE GEOLOGY AND ARCHAEOLOGY OF CYRENAICA B01

shoal facies onlap the Palaeogene beds in a narrow, structurally-controlled belt (Figure 14). Stop 4: Outcrops along the Al Abyar-Deryana roadcut (Figure 15) are exposed on the southern extension of an anticlinal structure, where beds dip a few degrees to the southwest. This section consists of Eocene, Oligocene and Miocene beds. The Eocene terms at the base of the section are covered by Pleistocene beach-dune deposits at 120 m a.s.l. These remnants of the Mediterranean Pleistocene eustatic sea-level change were tectonically uplifted as a result of the Quaternary and present-day uplift of Cyrenaica (El Hawat et al., in press). In this roadcut we shall examine: 1) Lower Oligocene Algal limestone, Al Bayda Fm.; 2) Middle to Upper Oligocene beds, Al Abraq Fm.; 3) Lower Miocene beds, Al Faidiyah Fm.; 4) the Miocene Benghazi Fm; and 5) Upper Miocene beds Wadi al Qattarah

Figure 12 - A lithologic log of a typical Messinian section exposed at the Hawa al Barraq gypsum quarry, showing one of the salina lake facies typifi ed by giant crystalline gypsum interrupted by a storm-induced gypsarenite layer, carbonate channel-beach facies and algal stromatolites. at the Sirt rift system. Conditions in this area led to the development of thick, coarsely crystalline gypsum lenses, algal stromatolites, coarse channel-beach storm deposits, and salina lake margin evaporite- solution collapse breccia associated with tepee Figure 13 - A view of the Messinian giant crystalline structures and bedded chert with pseudomorphs after gypsum facies exposed at the Hawa al Barraq gypsum gypsum (El Hawat, 1980). quarry and a layer of gypsarenites interrupting the PR01 to B15 n° 1 - from Volume These Messinian facies are the youngest deposits on crystalline sequence (arrows), suggesting reworking the southern fl ank the Al Jabal al Akhdar structure. during a storm event. These salinas were developed in a syncline on the northern fl ank of the main axis of the anticlinorium. Fm. of the Ar Rajmah group (Figure14). All of these Although the whole Miocene sequence in this locality stratigraphic units are separated from each other by is thick, it tapers out to the north, as the Middle unconformities, and each forms a single shallowing- Miocene beds pinch out and the Tortonian oolitic up sequence, refl ecting the interplaying of eustasy

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Volume n° 1 - from PR01 to B15 B01 - B01 Leader: A.S.El-Hawat calcilutite andcalcisiltite along theroadcutintohard These bedsgradeupsection coarse sandandgranules. and reworked limestone contains occasionalpolished (Figure 16),whichalso well asvery ﬁ bioturbated calcisiltiteas laminated, occasionally delicate, small-scale,cross that thesebedsconsistof Close examination reveals few degrees tothenorth. that isgentlyinclineda 1980), chalky limestone Helmdach andElKhoudary, (El Khoudary, 1976,1980; bedded Eocene,Lutetian consist ofsoft,well- previous stop. The outcrops we drive northfromthe which wewillseeas Farzugha anticline’s crest, general locationofthe stop coincideswiththe The Wadiroadcut Bacur Al Stop 5: tectonics. and Al Jabalal Akhdar escarpment of Al Jabal al Akhdar. Figure 14-GeologicalmapandcrosssectionoftheMiocene, Ar-Rajmah Groupisexposedalongtheﬁ ne calcarenite ne roadcut showing thePalaeogene-Neogene succession. Figure 15-LithologiclogoftheDaryanah-Abyar rst 20-05-2004, 8:47:48 THE GEOLOGY AND ARCHAEOLOGY OF CYRENAICA B01

Figure 16 A view of the Eocene outer ramp exposure of the Apollonia Fm. along the Tukrah roadcut. Beds are slightly inclined to the north and consist of well-bedded, chalky calcisiltite, and very ﬁ ne calcarenite that exhibits small-scale current structures and bioturbation.

mudstone associated with chert and interbedded with chalk. These in turn change into calcisiltite and fi ne calcarenite at the top of the roadcut. The succession is interpreted as deep neritic outer ramp facies that were deposited on the northern limb of the Al Jabal al Akhdar anticlinorium. These facies belong to the Apollonia Formation, and as we shall see later they transition upward and laterally into mid-ramp diachronous nummulite bioaccumulations. The cross lamination observed in the muddy facies of these outcrops are a result of the fi ne-grained carbonates being reworked by deep shelf currents (El Hawat, 1986a, 1986b). Stop 6: As we approach the town of Al Marj we will make a brief stop to examine at the fi rst appearance of the Lutetian Volume n° 1 - from PR01 to B15 n° 1 - from Volume Figure 17 - Lithological log of the Middle Eocene Dernah Formation in Al Marj limestone quarry. The base of the section consists of midramp Nummulite gizehensis banks, followed by inner ramp skeletal shoals and shelf lagoonal mudstone and wackestone that exhibit soft sediments deformation.

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Volume n° 1 - from PR01 to B15 B01 - B01 Leader: A.S.El-Hawat larger foraminifera in Al Jabalal Akhdar. the palaeontologyof and Barbieri(1999)for 2000) and Abdulsamad (1999, to Abdulsamad of thesoftmatrix.Refer differential weathering ground asaresultof scattered looselyonthe as nummuliteshellsare a fossilcollectionstop, ramp settings. This is the outerandmid- in sedimentationbetween as thereisacontinuum boundary istransitional, The Dernah-Apollonia the DernahFormation. that wearelookingat This outcropsuggests ramp bioaccumulation. forebank facies ofthemid- which representsthe Nummulite gizehensis, part ofarimhigh-energy depositsthatsurrounded with coarse-grainedshoalfacies inthisexposure are The Eocenenummuliticbanksanditsassociation Cretaceous on. throughout thestratigraphyofCyrenaicafrom seismic shock;itisacommonfeaturethatobserved were producedasaresultoftectonically-induced exhibiting softsediment deformationstructuresthat top ofthequarry. This successionincludesaunit and molluscanskeletal wackestone sectionatthe ramp, shelf,lagoonalfacies consistingofamudstone shoal system. These thenchangeupwards intoinner- (Figure 18),forminganummuliticbank-channel- ramp, coarse-grainedskeletal grainstoneandrudstone quarry, turningintoacomplex sequenceofinner Nummulite gizehensis one depositionalsequence.Itstartswithmidramp this outcropthesuccession(Figure17)consistsof ramp thantheoutcropsatprevious two stops.In We areonahigherpalaeoslopepointtheEocene of thismajortranspressionfault system. agriculture plain,whichformsthedownthrown side al Abid Cretaceousinlieroverlooking Al Marj faulted blockonthenorthernmargin oftheJardas The Al Marjlimestonequarryislocatedonanup- Stop 7: packstoneatthebaseof

Figure 18-Closeupofthechannel structuresintheinnerramp al Abid inlier.al Abid an islandoft visit thisarchaeologicalsite. the establishmentofCyrene. We shallhave time to the development ofthefountain Apollo, thatledto succession ofmarlsandcarbonateswas importantto the anticlinorium. The OligoceneandLower Miocene Oligocene outcropslocatedonthenorthernmargin of the way wewillmake shortstopstohave alook atthe the afternoonamongwell-preserved ruins. Along ancient GreekcityofCyrene,wherewewillspend inlier chalksareexposed, andthendrive tothe remnants ofthePalaeocene (Landenian)out to visitanotherinversion structurewhereeroded These willbefollowed byaquickstopatUwayliah, Dukhan dolomiteFormation (Maastrichtian). limestone Formation (Campanian)andthe Wadi al (Turonian-Coniacian-early Santonian),the Al Majahir marl Formation, the Al BaniyahlimestoneFormation Upper Cenomanianexposures oftheQasral Abid Abid village.Intheinlierweshallexamine the inversion structureislocatedaroundtheJardasal in northernCyrenaica(Figure4). The coreofthe the CretaceousinliersthatarealignedENE-WSW up thesecondplateautowards thecoreofone Today wewilldrive southform thetown of Al Marj skeletal shoalfacies, Al Marjlimestonequarry. inverted CretaceousrocksoftheJardas DAY 2 20-05-2004, 8:48:06 crops’ THE GEOLOGY AND ARCHAEOLOGY OF CYRENAICA B01

Stop 1: Drive from the hotel to the Al Marj-Abyar road, where we will then turn at the eastern branch of the fork leading to the village of Jardas al Abid, at the core of the Cretaceous inlier (Figure 19). After crossing the Eocene outcrops we shall stop at the Maastrichtian outcrops of the Wadi al Dukhan Formation. Looking west, we will observe a spectacular panorama that shows the unconformable relationship between the Cretaceous and the Tertiary strata. Stop 2: A short stop at the boundary between the Al Majahir (Campanian) and Al Baniyah (Turonian- Coniacian) Formations. We shall take a short walk to examine these formations in roadcuts and quarries; then, a walk up the (Majahir Fm.) hill will offer a bird’s eye view of the inlier (Figure 20). According to the mapping of the area, the boundary between the Figure 19 - Geological map of the Jardas Al Abid inlier (source: El Hawat and Al Baniyah (Turonian Shelmani, 1993). Volume n° 1 - from PR01 to B15 n° 1 - from Volume

Figure 20. Panorama showing the northern part of the Jardas Al Abid inlier, with the Eocene Dernah Fm. to the north and the Turonian – Santonian, Al Baniyah Fm. to the south.

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Volume n° 1 - from PR01 to B15 B01 - B01 Figure 22-GeologicalMapoftheUwayliah inlier. (source:Kaabar andBaird,1973). Leader: A.S.El-Hawat Figure 21-ExposureoflenticularrudistbiohermintheCampanian Al MajahirFormation. Dukhan formations. Majahir and Wadi al Baniyah, Al the Al Cretaceous bedsof consist ofinclined faulted blocksthat shall observe some towards Jardaswe drive alongtheroad al inliers (Rohlich northern Cyrenaica inversion ofthe led tothemain tectonic event that intra-Santonian coincides withthe unconformity. This marked byan formations is (Campanian) Majahir and Al to earlySantonian) al Akhdar.The site in Al Jabal third recordedrudist the is 1993). This and Shelmani, Formation (ElHawat for the Al Majahir a Campaniandating Durania sp identiﬁ rudist, 21). This rudist site(Figure a newly- discovered roadcut toexamine A quickstopata Stop 3: ., 1996). As we e as ed , suggests 20-05-2004, 8:48:16 et

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Figure 23 - View of the Uwayliah inlier looking west. The road passes almost parallel to a major fault zone where the Palaeocene Uwayliah Fm. is exposed. The over laying bed of the Eocene Dernah Fm. is almost horizontal south of the fault, but dips at a higher angle to the north towards the Al Marj trough.

fi rst is found in Wadi al Dukhan (Maastrichtian) Stop 5: outcrops in the Uwayli ah inlier, which was reported Driving east from Al Marj, 2.5km east of Uwayliah in unpublished AGIP fi eld notes during 1960. The village we will see the second Cretaceous-Palaeocene second locality is reported south of the Al Majahir inversion inlier (Figure 22). This area is strongly fortress in the Al Baniyah Formation (Rohlich, 1974). faulted and structurally complex. Here there is The rudist build-up at this locality occurred in a a possible element of wrench tectonics as it lies shallowing up cycle, where rudists form a lenticular along the margin of the Al Marj trough and north body dominated by skeletal rudstone debris around a small bioherm of rudist boundstone, suggesting that rudists are often preserved as skeletal debris rather than true reefal build-ups. Stop 4: Passing the Jardas al Abid Fort on the left (elevation 650 m), we shall drive on to the village school where the Qasr al Abid Formation is exposed. According to Barr (1968), the oldest beds exposed in the vicinity are of Upper Cenomanian age. The base of the unit is reported to be in well A1-18, 700 feet below the surface. The Cenomanian at this site consists of a shallow water fauna of oysters, echi noids, benthonic foraminifera and ostracods, in addition to a small percentage of plankton ic forams. In contrast, the Figure 24 - A view of the Palaeocene-Eocene Cenomanian in Ras al Hilal, on the coastal area, which section south of the fault. presents deeper marine traits, and is dominated by PR01 to B15 n° 1 - from Volume planktonic fauna. Before we depart from the Jardas of the larger inlier that we have just seen at the last al Abid inlier, it is worth mentioning that the area was stop. In this locality the Paleocene is overlain by the site of the fi rst oil well drilled in Libya (A1-18), the Maastrichtian Wadi al Dukhan Dolomites that by the Libyan – American Oil Company back in 1956. were pushed up by a reverse fault. No fossils have Remnants of this historical exploration site are still been reported from these massive dolomites in this observable today. We shall pay a visit to the well site, area; however, rudist reefs were reported in the old if time permits. AGIP fi eld notes referred to earlier. Dips of up to 15

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Volume n° 1 - from PR01 to B15 B01 - B01 Leader: A.S.El-Hawat inversion. as wellsubse in pre-Paleocene palaeotopographicconfi between theselocalitiesisascribabletodifferences differenceage Danian. The other, atJardasalJarariis Landenian inage,whilstthe Akhdar. This exposure is exposures in Al Jabalal of two confi road (Figure24). This isone found ontherightsideof Al Uwayliah Formation, lays intheexposure ofthe The importanceofthissite 23). Dernah Formation (Figure overlain bytheEocene sequence isunconformably Cretaceous –Palaeocene in thedolomitebeds. This degrees have beenmeasured going toseetomorrow. eastern outcropsoftheanticlinorium,whichweare changes intocoral-coralgaldominatedfacies onthe the nummuliticbioaccumulationfacies ofCyrenaica of thewhole Al Jabalal Akhdar anticlinorium,where leeward carbonatesedimentationonthelarger scale islands. We willbediscussingthewindward vs. deposited ontheleeward sideoftheCretaceous shoals, whereasthe Al Marjshoalstothewestwere facies areinterpretedasrepresentingthewindward rim aroundtheCretaceousinliers,thesehigherenergy very highenergy setting.Sinceallshoalsformeda in massive beds(Figure25).Itwas depositedin a with smallnummulitesandcoralfragmentsthatoccur is coarser, skeletal whole-shellcalciruditeassociated Al Marjquarry(fi inner rampshoalfacies wehave alreadyseenatthe the DernahFormation isalateralequivalent ofthe road aswedrive toCyrene.Facies inthisquarryof A glanceattheEoceneoutcropsonleftof Stop 6:[Optional] structures. Initselftheslumpisnotthatspectacular, Bayda Formation, exhibiting syndepositionalslump Marl Member’s Lower Oligoceneunitof the Al at Zawiet al Argoub, wherewecan see theShahat A quickstopalongthe Al Marj-AlBayda-Cyreneroad Stop 7: rmed Paleocene rmed rst day, stop7).However, thisfacies quent tectonicsanderosionduring debris ofthewindward beach-shoal complex. wackestone, overlain bycoarsebio-skeletal high-energy of well-bedded, lagoonal,orbitolite-rich mudstoneand Figure 25-EastoftheUwayliah Eocenesectionconsists guration, The areaofancientCyreneislarge andcomplex, and crucifi that helpedChristtocarrythecrossonhisway to afternoon amidtheruinsofbirthplaceman Cyrene was founded. We shallspendtherestof the smallertown ofShahatwherethe ancient cityof Driving pastthetown of Al Bayda,goingeasttowards Stop 9: 7, day1 around thestructurallyhigherareastosouth(stop with thehigherenergy, midrampfacies whichoccur lagoonal facies withsmallnummulites,ascompared outcrop lithologyintheareaconsistsofmuddy, shelf was highersubsidenceduringtheEocene.Eocene are inthemiddleof Al Marjtroughwherethere crossing thetopofwadi above us.Structurally, we boundary coincideswiththelevel ofthebridgeseen and Mediterraneanvegetation. The Eocene-Oligocene Jabal al Akhdar landscapeofEocenelimestonecliffs Another quickstopat Wadi alKuf toenjoy the Al Stop 8: Hawat, 1997). with theinfl the endofcarbonatedepositionsinNorth Africa involving theupliftingof African platethatledto North African events; withtheregional tectonics uplifted. The Oligocene indeed,was atimeofgreater time thatnorthernCyrenaicawas beingdifferentially rapid subsidence(SmithandKarky, 1993),duringthe thickening oftheOligocenesequence,asaresult slump structuresareassociatedwithasubstantial xion, SimontheCyrenian. ), andtothenorth(stop1,day3) ux ofsiliciclasticstowards the Tethys (El submarine fans and occurrence ofextensive of theSirtbasin, In theoffshore area recent time. the Mioceneandin Oligocene, aswellas, cover page),Eocene, in theCretaceous(see commonly observed These slumpsare sedimentary record. signature inthe process, andtheir the ongoinginversion in Cyrenaicadueto persistent tectonics but itdemonstrates the . 20-05-2004, 8:48:21 THE GEOLOGY AND ARCHAEOLOGY OF CYRENAICA B01 Volume n° 1 - from PR01 to B15 n° 1 - from Volume

Figure 26 - General map showing the ancient city of Cyrene (source: Goodchild,1970).

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to explain its history we would need a specialized situated on the mainland between Bomba and Dernah, guide. However, as an introduction guide to the at the mouth of Wadi Kalij. Here they remained ruins of the ancient city of Cyrene, a general map of another six years, in the course of which they learned the city, including maps of the Agora-Forum and of that even better sites lay on the high plateau farther the Fountain and Sanctuary areas, are here provided to the west. Friendly Libyans offered to guide them (Figure 26). The following brief account and map to a place where they could establish their permanent are derived from a historical guide published by the settlement. These guides were, however, anxious to Libyan Department of Antiquities (Goodchild, 1970). prevent the Greeks from seeing IRASA, the fi nest part of the country. This place is perhaps Dernah itself on The Founding of Cyrene Ain Mara. So the march was made at night and when The story of the foundation of Cyrene as a colony of dawn broke the travellers found themselves on the Greek immigrants from the island of Thera (modern future site of Cyrene. “Here, O Greeks,” said their Santorini) has been handed down to us as a mixture guides, “ye may fi tly dwell, for in this place there is a of legend and history. The date usually assigned hole in the heavens”. The Libyans referred , of course, to this event is 631 B.C. It seems that to wards the to the abundant rainfall of the Cyrene area. Their own middle of the seventh century B.C. a crisis due to numbers were small, and the country was large; in all overpopulation arose on the small Aegean island, and probability they themselves were only thinly scattered a seven-year period of drought caused such distress on the upper plateau, fi nding its winter climate too that forced emigration seemed the only solution. So harsh for their African blood. But the Greeks were captivated by a landscape not unlike the Greek mainland, and relatively free from those droughts which they had suffered on Thera. There was good arable soil and ample pasture; most important of Figure 28 - The upper sequence of the mid-ramp nummulite succession of the Dernah Fm., Cyrene road cut. Note the accretionary arrangements of the nummulite bodies (arrows), and the all, the Libyans Eocene-Oligocene boundary (dashed line). were friendly and willing to the leaders of the community consulted the famed give their daughters in marriage to these foreigners Oracle of Apollo at Delphi, and were told to found who had arrived without their womenfolk. King a colony in Libya. An expedition was organized and Battus ruled for forty years over his tiny immigrant entrusted to a certain “Aristoteles”, who later took the community, and by all accounts he ruled wisely name of Battus and became the fi rst king of Cyrene. and moderately. Although still a minute nucleus, in Some 200 young men were nominated to accompany comparison with the city that was to develop in later Battus, and from Thera they sailed to Crete where years, Cyrene began to take shape. A temple of Apollo they found a pilot to lead them to the shores of Africa. the “founder” was erected close to the spring which They founded the fi rst settlement on a small island was named after the nymph Cyrene (Kura or Kurana), called Platea in the Gulf of Bumba, on the eastern and a straight approach road was laid down on the outskirts of the fertile Cyrenaican plateau. The fi rst plain. When Battus died his tomb was venerated and PR01 to B15 n° 1 - from Volume settlement on the island of Platea was not successful. a public place of assembly, the later Agora, grew up The isle was small and there was little water. After two around it. years the settlers decided to consult the Oracle again and were advised to go to the mainland. Convinced that they had yet to fi nd the true Libya, the settlers returned to Africa and moved their settlement from the arid Platea to a more favourable site called Aziris,

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Volume n° 1 - from PR01 to B15 B01 - B01 Leader: A.S.El-Hawat Jabal al Akhdar anticlinorium. The crestofthisfold is anotherstructureonthenorthernlimbof Al of whichistrendinginaNE-SWdirection. This are attributable totheoccurrenceofafold,axis Formation. The presenceofthe Cretaceousexposures sediments aredominat To theeast,innarrower coastalplain,Cretaceous composed largely of the Al Hilalshale Formation. coastal plainofMersa western partoftheinliercoincideswithwidened is alsoexposed inbeachcliffs andwadi cuts. The wadi andbeachQuaternarydeposits. This sequence coastal plainandisoverlain byamixed sequenceof area theUpperCretaceoussequenceisexposed onthe Jabal al Akhdar inthisexcursion maybeseen.Inthis Hilal- Athrun wherethelastMesozoicinliersin Al We willthendrive alongthecoastal roadtoRasal permits itwewillstopatthearchaeologicalsites. (Susa) fromtheﬁ down tothecoastview thetown of Apollonia escarpment whereCyrenewas founded,thendrive We willcontinuetoexamine thegeologyofupper terrace isat120ma.s.l.(centre).Susavillage(Apollonia)totheleft. hanging wall exhibits tectonicallyelevatedwave-cut terracing.Thelower edgeofthe Figure 30-Faulted Eocenebedsshowing kneefold onthefootwall (leftofcentre).The rst escarpment,ifourschedule DAY 3 ed bythe Al Athrun limestone Marsa RasalHilal,andis First, atthewestDernahroadcutwherewewillsee Bengha zi weshallmake two otherimportantstops. turbidite feederchannels.Onourdrive backto marine mid-rampfacies associatedwithforebank to beseenlaterintheafternoon,consistsofshallower ramp. The toppartoftherampsuccession,whichis movements inthelower partoftheouterEocene with slumpfeaturesrepresentingsubmarinemass Cretaceous-Eocene unconformitiesandsequences today. At thevillageof Al Athrun weshallseethe in roadcutsandbeachcliffs inaspectacularsetting We willbeexamining thesesequencesandfacies altogether. Bumba, theUpperCretaceoussequenceismissing the Al MajahirFormation. To theeastinGulfof sequence isinterruptedbyashallow water unitof To thewest,inBenghazioffshore, Al Hilal- Athrun are inter (Apollonia) highway offers agoodopportunity to The new roadcutalongtheShahat(Cyrene)- Susa The CYRENE-APOLLONIAROADCUT. Stop 1: rupted bytheintra-Santonianunconformity. shallower water origin,and Cretaceous sequencesareof south, theequivalent Upper in theJardasinlierto the inversion anticlinorium is gradational.Onthecrestof limestone and AlAthrun shales boundary betweenthe Al Hilal missing over thisarea. The Several stratigraphicunitsare the villageofRasalHilal. located immediatelysouthof coincides with Wadi alQalah, gizehensis, Cyreneroadcut. Middle Eocene,Nummulites Figure 29-Close-upofthe channel. Then, at the at channel. Then, Ain Oligocene debrisﬂ west, andtheassociated bioaccumulation tothe Eocene nummulite equivalent ofthe the windward reefal coralgal reefal complex. including theOligocene Palaeogene sequence, we canexamine the Ad-Dabusseyah roadcut, 20-05-2004, 8:48:37 ow ow THE GEOLOGY AND ARCHAEOLOGY OF CYRENAICA B01

Figure 31 - General map of the ancient city and port of Apollonia (Susa). (source: Goodchild, 1970). examine the complete Eocene-Oligocene-Miocene 28). This cycle was a result of progradation of the section (Figure 27), which makes up the second Al shallow water coralgal-reefal carbonate facies over Jabal al Akhdar escarpment. The roadcut also offers the deeper Shahat marl Member neritic shelf muds one of the best locations to study larger foraminifera . The Al Abraq and Faidiyah Formations present (Abdulsamad, 1999, 2000). The base of the section similar shallowing-up sequences. It is important to consists of massive units of the Middle Eocene re-emphasise that the Al Jabal al Akhdar tectonics Dernah Formation. The nummulitic bank complex were active during sedimentation of these sequences. is underlain by back-bank, Orbitolite wackestone and These tectonic activities infl uenced sedimentation and mudstone facies forming the top of the Eocene middle the facies thickness distribution. We shall talk more sequence. about that later. The bank com-plex consists of a series of lenticular Volume n° 1 - from PR01 to B15 n° 1 - from Volume nummulitic bodies that exhibit coarsening up vertical Stop 2: sequences. We will derive down the upper escarpment, the These bodies are stacked on top of one another and fi rst plateau, and as we are midway along the fi rst also, develop large-scale, prograding, sigmoidal, escarpment we could make an optional stop to enjoy trough and draping primary structures (Figs. 28, the view of the coast where Apollonia, the harbour 29). The Lower Oligocene Al Bayda Formation also of Cyrenaica was founded. Looking eastward along displays a single shallowing up depositional cycle, the escarpment note the prominent terrace: this is unconformably underlain by the Eocene (Figure an elevated Pleistocene wave-cut terrace (Figure 30).

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Volume n° 1 - from PR01 to B15 B01 - B01 in theseacliffs andarecovered byQuaternaryrocks inthenarrow coastalarea(source:Rohlich, 1974). Figure 33-GeologicalmapoftheRasalHilalarea.The Cretaceousbedsareshown onthemapastheyform outcrops Leader: A.S.El-Hawat gravel, whichmayoftenbecovered inturnbymore are partiallycovered bycalcite-cemented ﬂ and associatedbeach-dunecalcarenitecomplexes terraces mayvary fromplacetoplace. The terraces may have erodedaway, andhencethenumberof eustatic events. Someofthehigherterraceshowever ones suggestthattectonicwarping overprinted meters, isconstantthroughoutCyrenaica,thehigher meters above sea-level. Whereas thelowest one,6 15 –25,3540,4455,7090and140190 shoreline depositsofnorthernCyrenaicaoccurat, Hey (1956)demonstratedthattheQuaternary about 120meters. The seaward edgeofthisfeaturehasanelevation of the Cretaceous-Eoceneinlierforming thecliff inthebackground. Figure 32-Panoramic viewtaken fromtheRasalHilalheadlandlookingsouthtowards uvial ridge ontheCyrenaicanoffshore (ElHawat has alsoledtothedevelopment oftheMediterranean conversion ofthe African andEurasianplates,which press). to theongoingcompressive inﬂ Cyrenaica sincetheendofMiocene. This isdue tectonic movements thathave affected northern anomalous dips. These arearesultofthevertical folding ofthefootwalls, wherethebedsoftenexhibit fault-controlled wave-cut cliffs thatexhibit knee recent alluvium. These featuresareassociatedwith uences inducedbythe et al 20-05-2004, 8:48:42 ., in THE GEOLOGY AND ARCHAEOLOGY OF CYRENAICA B01

Stop 3: from Crete. It was extensively rebuilt in the Italian APOLLONIA occupation as a port for coastal shipping and an This is an optional stop. Drive down the escarpment to administrative centre. The ancient town of Apollonia Susa, to look at the ancient ruins of Apollonia (Figure is fairly well preserved, as it lies almost entirely 31). The following are extracts from Goodchild outside the modern day Susa. The principal damage (1970). to the ruins has been caused by the sea, following a subsidence of the coastal area during the late antiquity Marsa Susa (Apollonia) is located on the periods due to the ongoing tectonics of Cyrenaica. Mediterranean coast, twenty kilometres north of Apollonia was given its name in honour of the patron Shahat (Cyrene). Ancient Apollonia was Cyrene’s god who brought the Greeks to Libya, but in Christian port for over a thousand years, and its ruins form an times it was commonly called “Sozusa”, from which essential part of the whole archaeological complex. has developed the Arab name “Susa”. Although The modern Cyrene-Apollonia road follows the Apollonia was the port of Cyrene, its prosperity was course of the ancient highway linking the city to the such as to give it autonomy during the Roman period, port. Originally constructed by the Greeks, it was later when it was recognized as one of the ﬁ ve cities of the improved in A.D. 100, to be partly destroyed ﬁ fteen Pentapolis of Libya (Goodchild, 1970). years later, by the Jewish insurgents. After further

Figure 34 - Cross-section in the wadi Qala - wadi Athrun area located in Figure 3, showing the Cretaceous - Eocene inlier at the Ras al Hilal area. (source: Barr & Berggren, 1980). Volume n° 1 - from PR01 to B15 n° 1 - from Volume repairs it remained in use until the Arab conquest During our drive east of Susa we will point out an of Libya. The highway was chiselled squarely into important archaeological site about 7 kms east of the Eocene rocks, with sidewalks on either side, it the town. A karstic cave can be observed in the face passed through Cyrene’s northern ne cropolis. The of a low lying northern-facing Eocene rock scarp, construction of the new asphalt road after 1914 has located east of wadi al Hira. This is the world famous changed its appearance. Modern Susa (Apollonia) “Haua Fteah” cave. The site was made famous by was founded in 1897 as a colony of Moslem refugees archaeological, palaeontological, climatological

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Volume n° 1 - from PR01 to B15 B01 - B01 Leader: A.S.El-Hawat phases have beeninterpreted. sets, cyclic climatic the acquireddata ﬂ meters inthecave sample depthof7.5 This was froma 46,000 yearsBP. obtained hasbeen The oldestC14age meters inthecave. to adepthof13 have beenexcavated unknown thickness Deposits of in North Africa. prehistoric sites most important This isoneofthe McBurney, 1967). and Hey, 1955; (McBurney several researchers publications by and geological discovered byBarrandHammuda(1971), form thecoreofRasalHilalinlier. They were Al HilalshaleForma tion isexposed. These shales and walk down thesea-cliff wheretheCenomanian, we’ll entertheRasalHilalMotel,eastofvillage, Hilal – Athrun Cretaceousinlier. To examine itsrock (Figure 34)demonstratethedevelopment oftheRasal The geologicalmap(Figure33)andcrosssection at work. Mediterranean ridgewherecompressive forcesare into theMediterranean.Itisalsoclosestto the mostforward-jutting pointoftheLibyancoastline headland isthetipofCyrenaicanpromontory, and inlier andthevillageoncoast(Figure32). This escarpment oftheRasalHilalCretaceous-Eocene south willshow animpressive panoramaofthe on thenorthside. A view fromtheheadlandlooking Ras alHilal(theCrescentHead)headlandappears tectonics atonetimeoranother. Furtheralong,the incised wadies. All thesefeaturesevolved dueto faulting andtiltingofbeds,aswellpronounced These exhibit prominentsyndepositionalslidescars, south sideoftheroad Apollonia Formation outcrops. As wecontinuetodrive eastwecanobserve onthe Stop 4: oor deposits.Fro Note unconformities (arrows), nanno-planktoniczones.(source:ElHawat, inpress). Figure 35- A viewofCretaceous-Eocenesectioninwadi Athrun. section. The overlying Eocenesequencehasproduced there actuallyarePaleocene beds atthebaseof This hascausedsomepalaeontologiststobelieve that marked byapebbly Cretaceous-Lower Tertiary boundary(Figure36)is in thissequence.However, inplaces,theUpper Apollonia Formation. The Paleocene ismissing the overlying tan-co loured bedsoftheLower Eocene, which marksthecontactbetweenCretaceousand the south. These areoverlain byathin,tan,marlyzone Cretaceous bedsarewhiteandhave avery slightdipto Lower Tertiary sequence(Figure35). At thebase, dimensional panoramaoftheUpperCretaceous- The easternwall ofthewadi presentsauniquetwo trough fromthe Tethys. a submarinebarrierthatseparatedtheCyrenaican to thesouth. These shales weredepositednorthof Jardas al Abid inlierattheaxisofanticlinorium al Abid and Al BaniyahFormations observed inthe exposures arethedeep-water equivalent oftheQasr were datedUpperCenomaniantoConiacian. These Stop 5: from theGreekname After driving easttothevillageof Al Athrun (derived ourselves tospectaculargeologicscenery to theshallow bottomofwadi al Athrun totreat

zone withPaleocene lithoclasts. Erythrum ), weshallwalk down and history. 20-05-2004, 8:48:49 THE GEOLOGY AND ARCHAEOLOGY OF CYRENAICA B01

Figure 36 - Close-up of the light-coloured chalk of the Upper Cretaceous (Maastrichtian) Athrun Formation, and tan-coloured Lower Eocene (Ypresian) rocks. The K/T unconformity is overlain by a shaley layer containing reworked Palaeocene pebbles (source: El Hawat, in press).

bed below this unconformity was deposited in a bathyal environment. The slump section above the unconformity is 10m thick and consists of shallow neritic mid-ramp nummulitic wackestones facies. This sequence is followed by normal, well-bedded, deep neritic, outer-ramp Apollonia facies. Clearly, the slump unit indicates submarine mass movements of planktonic forams and nannofossils of Ypresian age. shallow- water nummulitic facies into a deep water It is followed by a Lutetian slump unit. A few meters setting (El Hawat, 1985 & in press). Ideas concerning upsection, below the slump unit, an unconformity this section are currently in the process of being within the Ypresian is marked by a glauconitic, published. The interplay between global eustasy and pebbly bed. This form eustatic unconformity marking local tectonics will be discussed. the boundary between Nannofossil zones NP13 and NP14. The following base of the slump, on the other Stop 6: hand, marks the Ypresian-Lutetian unconformity This is an optional stop at the sea-cliff exposed at the boundary between NP14a and NP14b (Figure 37), mouth of Wadi al Athrun (See cover page). Exposures with a hiatus of about 3 million years, and suggests of the Al Athrun limestone Formation are overlain by a eustatic event overprinted by tectonics (El Hawat, Quaternary deposits. The section is part of the Barr in Press). The planktonic foraminifera packstone and Hammuda (1971) type section. This beach cliff Volume n° 1 - from PR01 to B15 n° 1 - from Volume

Figure 37 - Close-up of the Ypresian-Lutetian boundary below the slump unit. The boundary represents a hiatus of about 3 million years (source: El Hawat, in press).

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Volume n° 1 - from PR01 to B15 B01 - B01 Leader: A.S.El-Hawat the Eocene(El Al Jabalal Akhdar structureduring represent thewindward sideofthe the Mediterranean.Itisbelieved to before itplungeseastwards into Al Jabalal Akhdar anticlinorium It formstheeasternedgeof facies wehave examined sofar. major changefromtheEocene roadcut. This roadcutoffers a to examine thewestDernah road thatwindsuptheescarpment of Dernahandturnrightatthe Drive tothewesternapproaches Stop 7: bathyal conditions. ranging fromdeepneriticto marine, lower-slope sedimentation Chondrites ichnofauna as fragments, aswellsuch planktonic forams, Al Athrun chalksarerichin along seismiclines. structures whicharerecognized by theoccurrenceoffault ﬂ wrenching. The latterisindicated events includeupliftingand earlier, theintra-Santoniantectonic the anticlinorium. As indi cated were takingplaceattheaxisof are relatedtotectonicevents that common intheformation. These of slumpstructureswhichare exposure shows agoodexample 1993). (source: ElHawat andShelmani, west Dernah roadcut. Figure 38-Lithologicallogofthe of theDernahFormation (Figure mid-ramp nummuliticbankfacies the high-energy, shallow-water, ramp mudstones,gradinginto up successionof Apollonia outer- thick andrepresentsashallowing in thisroadcutisabout200m by Hammuda(1973). The section association ﬁ Eocene nummulite-reefal facies In press). We shallexamine the . These indicate deep- indicate . These rst describedindetail Zoophycosand Hawat et al Inoceramus 20-05-2004, 8:48:54 ., 2002; ower

THE GEOLOGY AND ARCHAEOLOGY OF CYRENAICA B01

38). This section is reduced in thickness when compared to other sections to the west. This facies passes into a back-bank, inner- ramp, coralgal-discocyclinid carbonate sand shoal-channel facies complex that, in turn, grades into a succession of restricted inner-shelf lagoonal facies which exhibit intensive dolomitization, dissolution discontinuity surfaces, and other features consistent with subaerial exposure. The upper part of the cycle shows early development of patch reefs with intermittent phases of subaerial exposure, followed by a thick sequence of solitary corals, then topped by a succession of massive corals. Figure 39 - A view of the Eocene-Oligocene unconformity. The overlaying sequence is dominated by a back The top of the Eocene section shows the development reef, coralgal-discocyclinid, sand shoal complex. of a nodular lithifi ed hardground followed by a brown- coloured paleosoil horizon. The Eocene-Oligocene boundary is marked by The Lower Oligocene consists of debris fl ow olistoliths intensively bioturbated hardground that develop a derived from the Eocene (source: El Hawat et al., in press) nodular appearance, and is followed by paleosols and terra rossa develop ment (Figure 39). These at the base of the section at stop 5) followed by high features suggest the end of the Eocene tectonic uplift energy midramp nummulitic bank facies that exhibit and subaerial exposure prior to the deposition of the large-scale prograding features. These deposits are Lower Oligocene, where the Shahat marl Member of reduced to thin units that exhibit a sharp sequence the Al Bayda Formation is missing, and the overlying boundary on top. These are the upper ramp facies, a algal limestone member consists of a single unit. continuation from the lower ramp sequence examined The Eocene-Oligocene boundary is followed by up earlier at Al Athrun. to 20m of a thick, massive, fi ning-up, debris fl ow Again the Oligocene Shahat marl is missing at the channel unit that contains olistoliths of reworked base of the Al Bayda Fm. in this section, as at the Eocene mixed with Oligocene facies. It suggests that west Dernah roadcut. However, the red paleosoil is the tectonic conditions that uplifted the area at the end also missing. The Algal limestone member exhibits a of the Eocene also continued to overprint the Lower shallowing-up cycle of sedimentation. It starts with Oligocene transgression. a cross-bedded Lepidocyclina-coralgal shoal-channel complex, which grades upwards into reefal-coralgal Stop 8: bioherms. The Lower-Middle Oligocene boundary is As we drive back to Benghazi along the main sharply marked by a dolomitized, orbitoid wackestone highway to Qubbah we will make an optional stop unit. The overlying Al Abraq shoal calcarenites are at the Ain Ad-Dabusseyah roadcut. In this roadcut charac teristically soft, yellowish, bioturbated, thick (Figure 40) again we shall examine the Eocene- bedded, echinoid-Operculina-Heterostegina-rich, and Oligocene sequence in order to improve our facies in places contain reworked nummulites. Apparently, PR01 to B15 n° 1 - from Volume models of the Palaeogene sequence. We are on the these were the rocks preferred by the ancient Romans highest southern point of Ras al Hilal. However, in to dig and establish archaeological sites, compared this sec tion, the Dernah Fm. is nummulite-dominated to the hard reefal limestone below. The overlying Al with no reefal development to speak of. Facies belts Faidiyah Formation on the other hand, produces the are fairly well defi ned with forebank gravity slope black soil that covers the upper plateau. This colour mass movement and turbidites (remember the slump is a result of the release and oxidation of ferrous iron from the basal glauconitic marl.

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Volume n° 1 - from PR01 to B15 B01 - B01 Leader: A.S.El-Hawat Abdulsamad, E.O.,2000.Contribution tothe Abdulsamad, E.O.,1999.Stratigraphyand References preparation ofthisguidebook. of ScienceandGaryounisUniversity duringthe by theDepartmentofEarthSciences,Faculty We would like toacknowledge thesupportprovided Acknowledgment cut (source:ElHawat andShelmani,1993) Figure 40-Lithologicallogofthe Ain Ad-Dabusseyah road Libya). Revue Paleobiol. Geneve, vol 19(1),pp. sequence of Al Jabalal Akhdar (Cyrenaica,NE Nummulites taxonomyfromthePalaeogene 75-98. Gournale diGeol.BolognaSer. 3,vol. 61,pp. from Al Jaballa Akhdar (Cyrenaica,NELibya). palaeogeography of Tertiary larger foraminifera El Hawat, A.S. 1986a.Fine-grained currentdrift El Hawat, A.S., 1980.Intertidaland storm Contant, L.C.,andGoudarzi,G.H.,1967.Stratigraphic Contant, L.C.andGoudarzi,G.H.,1964.Geologic Cavazza, W., Roure,F., Spakman, W., Stampﬂ Anketell, J.M.1996.StructuralhistoryofSirtbasin Abdulsamad, E.O.,andBarbieri,R.,1999. Campbell, A.S., 1968. The Barce(AlMarj) Barr, F.T. and Hammuda, O.S.,1971. Barr, F.T. andBerggren, W.A., 1980.Lower Tertiary Barr, F.T., 1968.UpperCretaceousstratigraphyof shoaling-up sequences;theEocene,NELibya.In carbonates andassociatedfacies inaslopetoshelf Academic Press,London,II:449-462. Salem &M.T. Busrewil (Eds.),GeologyofLibya. Ar-Rajmah Fm., Al Jabalal Akhdar. In:M.J. sedimentation from Wadi alQattarahMember, Assoc. Petrol.Geol.,51/4:719-730. and tectonicframework ofLibya.Bull. Amer. Survey., MapI-350 A. map ofLibya,scale1:2,000,000.U.SGeol. Mantel. Springer-Verlag. Atlas: theMediterraneanRegion fromCrustto G., Ziegler, P., (Eds.),inpress. The TRANSMED Cyrenaica platform,northernLibya.1 and itsrelationshiptotheSabratahbasin Micropalaeont., vol 18,pp.45-65. at Al Jabalal Akhdar (northeastLibya).Jour. interpretation oftheEocene-Miocenecarbonates Foraminiferal distribution andpalaeoecological 19-45. Libya. Petrol.Explor. Soc.ofLibya.10 geology andarchaeologyofnorthernCyrenaica, earthquake of1963.inF.T Barr(editor): The 1970, pp.27-40. proc. 2nd.Int.conf.Plankt.Microfossils.Rome, Shale, NotheasternLibya.In: A. Farinacci (Ed.), Upper Cretaceous Atrun LimestoneandHilal Biostratigraphy andplanktoniczonationofthe 162-192. Geology ofLibya. Academic Press,London,I: Libya. In:M.J.Salem&M.T. Busrewil (Eds.), biostratigraphy andtectonicsofnortheastern Annu. FieldConference, Tripoli, pp.131-147. Cyrenaica, Libya.Petrol.Explor. Soc.Libya,10th Barr (Ed.)Geologyand Archaeology ofNorthern the Jabalal Akhdar, NorthernCyrenai Amsterdam, p.57-89. A.A. MisallatiandM.A.Sola,Ed.)Elsevier, Sirt Basin. Vol. 3.(M.J.Salem,M.T. Busrewil, on theSediment.basinsofLibya.Geology ﬁ eld conference.P. 183-195. ca. In:F.T. st th sympo. 20-05-2004, 8:48:59 annual i, THE GEOLOGY AND ARCHAEOLOGY OF CYRENAICA B01

the 7th European I.A.S. Mtg. Ext. Abs. Krakow, stratigraphy and micropaleontology of Jabal Al Poland, P. 208-210. Akhdar; 1. Upper Eocene planktonic Foraminifera El Hawat, A.S., 1986b. Large-scale cross-bedded from Wadi Bakur, SE Tukrah, NE Libya. Libyan fi ne-grained contourites and associated facies; A Jour. Sci., 6B : 57-79. model from the Eocene of NE Libya. 12th. I.A.S. El Khoudary, R.H. 1980. Planktonic foraminifera from Congress (Abs.). Canberra, Australia, pp. 94. the Middle Eocene of the Norhtern escarpment of El Hawat, A.S., 1997. Sedimentary basins of Egypt: Al Jabal al Akdar, NE Libya. In: M.J. Salem and an overview of dynamic stratigraphy. In: K.J. M.T. Busrewil (Eds.), The Geology of Libya. Hsu (editor) Sedimentary basins of the world, Academic Press, London, I : 193-204. vol 3 African Basins (R. C. Selley, ed.),. Elsevier, Francis, M. and Issawi, B., 1977. Geological map Amsterdam, p. 39-85. of Libya; 1:250,000, Sheet NH 34-2, Soluq, and El Hawat, A.S., In Press. Sedimentology and event explanatory booklet. Ind. Res. Cent., Tripoli, 86 stratigraphy of the Lower-Middle Eocene pp. sequence, Apollonia Formation, Cyrenaica, Geological Map of Libya, scale 1:1,000,000. Libya. Earth Science Soc. Libya, Tripoli. Industrial Research Center, geological research & El Hawat, A.S. and Abdulsamad, E.O., in press. The mining department, Tripoli, Libya. (1985). geology of Cyrenaica: a fi eld seminar. Field Goodchild, R.G. 1968a. Graeco-Roman Cyrenaica. in Guidebook, Earth Science Soc. Libya, Tripoli. F.T Barr (Ed.): The geology and archaeology of El Hawat, A.S., Abdel Gawad, G.I. and Salem, M.J., northern Cyrenaica, Libya. Petrol. Explor. Soc. of 1993. Neogene carbonate discontinuity surfaces Libya. 10th annual fi eld conference. P. 23-40. in northern Libya. Sedimentary Basins of Libya, Goodchild, R.G. 1968b. Earthquakes in ancient Geology of Sirt Basin Symp. Abs. Earth Sci. Soci. Cyrenaica. in F.T Barr (editor): The geology Libya, Tripoli. P. 18. and archaeology of northern Cyrenaica, Libya. El Hawat A.S. and Argnani A. 2001. Libya and the Petrol. Explor. Soc. of Libya. 10th annual fi eld Pelagian shelf. In: G. Stampfl i, G. Borel, W. conference. P. 41-44. Cavazza, J. Mosar and P. Ziegler (Editors),The Goodchild, R.G. 1970. Ancient Cyrene. Libyan Dept. palaeotectonic Atlas of the PeriTethyan Domain of Antiquities. . IGCP 369 project CD-ROM. The European Hammuda, O.S., 1973. Eocene biostratigraphy of Geophysical Society. Derna area, Northeast Libya. Unpub. Ph.D. thesis, El Hawat, A.S., Barghathi, H., Obeidi, . in press. Univ. of Colorado, 177 pp. Cyrenaica - Transect VII. In W. Cavazza, W. Hey, R.W., 1956. The geomorphology and tectonics Roure, F., Spakman, W., Stampfl i, G., Ziegler, of Gabal Akhdar (Cyrenaica). Geol. Mag., v. 93, P (editors), The TRANSMED Atlas: the no. 1, p. 1-14. Mediterranean Region from Crust to Mantel. Huguen C., and Mascle, J., 2001. La Margie Springer-Verlag. continentale libyenne, entre 23o30 et 25o30 de El Hawat, A.S., Caline, B., Jorry, S., and Davaud, E., longitude est. C.R. Acad. Sci. Paris, Earth and 2002. The Eocene ramp complex of Al Jabal al Planetary Sciences, vol. 332, p. 553-560. Akhdar, Cyrenaica, NE Libya: A surface analogue Kaabar, S.M. and Baird D.W., 1973. Geological for nummulite reservoir. Abs. AAPG Inter. Petrol. fi eldtrip roadlog for Northern Cyrenaica, Libya. Conf., Cairo. p. A29. Petrol. Explor. Society of Libya , 115 pp. El-Hawat, A.S. and Salem, M.J., 1987. A Case Study Klen, L., 1974. Geological map of Libya; 1:250 of the stratigraphic subdivision of Ar- Rajmah Fm. 000. Sheet NI 34-14, Bengahzi, and explan atory and its Implication on the Miocene of Northern booklet. Indust. Resear. Cent., Tripoli, 56 pp. Libya. In: Proc. VIIIth Cong. Med. Neogene Mazhar, A. and Issawi, B., 1977. Geological map Stratig., Budapest. Ann. Inst. Geol. Publ. Hung., of Libya: 1:250,000 sheet, Zt. Masus NH- 34- PR01 to B15 n° 1 - from Volume Budapest, LXX : 173-184. 3, explanatory booklet. Indust. Resear. Cent., El-Hawat. A.S. and Shelmani, M.A., 1993. Short Tripoli, 80 pp. notes and guidebook on the geology of Al Jabal McBurnney, C.B.M., 1967. The Haua Fteah la Akhdar, Cyrenaica NE Libya. Interprint, Malta. (Cyrenaica) and the Stone Age of southeast 70 pages. Mediterranean. Cambridge Univ. Press. El Khoudary, R.H., 1976. Contribution to the McBurnney, C.B.M., and Hey, R.W. 1955. Pre-history

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Volume n° 1 - from PR01 to B15 B01 - B01 Leader: A.S.El-Hawat Rohlich, P.; Salaj,Jand Troger, K.,(1998). Rohlich, P., 1987.Geologicaldevelopment ofJabalal Rohlich, P., 1974.GeologicalmapofLibya;1:250,000 unconformity inGhawt Sasarea.InM.J.Salem, Palaeontological datingofthepre-Campanian Akhdar, Libya.Geol.Roundsc.,63/2:401-412. booklet. Indust.Resear. Cent., Tripoli, 70pp. sheet, Al BaydasheetNI34-15,explanatory Cambridge Univ. Press. and PleistocenegeologyinCyrenaicanLibya. Zert, B.,1974.GeologicmapofLibya,1:250,000, Smith D.N.andKarki,M.,1993.Basindevelopment Indst. Resear. Cent., Tripoli, 49pp. Dernah sheetNI34-I6,explanatory booklet. Basin Symposium(Abs.). Sedimentary BasinsofLibya,GeologySirt of offshore SirtbasinwestofBeng Amsterdam. Geology ofSirtBasin. Vol. I,p265-286.Elsevier, Mouzughi, A.J., andO.S.Hammuda(editors), hazi, Libya. 20-05-2004, 8:49:04 Back Cover: Road map of Cyrenaica marked by daily stops locations.

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