The zndominated deposits for which a mineralisation age has been established, formed after the pan african orogeny. Metamorphic zircon from metapelites and granitoid orthogneisses yielded ages of c. Following the pan african orogeny the kufrah basin shows evidence of extensional tectonics during the infracambrian to. The neoproterozoic brasiliano pan african orogeny is ubiquitous in eastern south america and western africa and represents a protracted amalgamation of major crustal blocks along several mobile belts, giving oriolo et al. Structural characterization of outcropscale in edea and. The metamorphic evolution of gneisses in orvinfjella. Three main periods of corundum formation are recognized. First direct evidence of panafrican orogeny associated with. The late precambrian to early paleozoic panafrican orogeny in. Over the past 15 years, new isotopic studies have improved our recognition of different tectonic events and associated processes, such as reactivation of shear zones and fluids circulation. These blocks were separated by oceanic basins, which were consumed and closed between 0.
The traditional sources are kashmir mainly sapphire. Growth and collapse of a deeply eroded orogen wiley online library. The activity resulted in structural modification and slight migmatization of the. The pan african system of orogenic belts in africa. As in other parts of africa, it suffered its most pronounced deformation and remobilisation during the pan african orogeny about 650450 m. Amsterdam africa pan african orogeny 1 contents pan african orogeny north african phanerozoic rift valley within the pan african domains, two broad types of pan african orogeny orogenic or. One of the structural features left following the panafrican orogeny was an elongate arch extending senw from the tibisti mountains to the vicinity of tripoli, and evidence of this arch is to be found in the separation of the kufrah and murzuq basins, in the brakbin ghanimah uplift. Several authors14 have advocated that in west africa the 500600 m. Emplacement ages for several pan african granitoids, obtained by upb and shrimp analyses, range from 730 to 655 ma. In its vaguer, more cultural, forms, pan africanism has pursued literary and artistic projects that bring together people in africa and her diaspora.
A reconsideration of pan african orogenic cycle in the. This orogeny is also known as the pan gondwanan or saldanian orogeny. Zircon evaporation ages from granitoid gneisses ranging from 2555 to 1740 ma and to 700 ma, which have been interpreted as intrusion ages reischmann et al. The pan african orogenic cycle refers to a series of protracted late neoproterozoic orogenic events that resulted in the amalgamation of. Panafrican basement and alpine deformation introduction. The pan african, respectively the brasilian orogenic events are charac. That event which was actually a series of smaller orogenies occurred when the two blocks of the former supercontinent rodinia collided with a craton the stable interior portion of a continent that would become the presentday congo region. In its most straightforward version, pan africanism is the political project calling for the unification of all africans into a single african state, to which those in the african diaspora can return. The nigerian precambrian and the panafrican orogeny. In the same year, 1915, duboiss little book the negro popularized the history of the african kingdoms south of the. A reconsideration of pan african orogenic cycle in the anti. These terranes were all affected differentially by the pan african orogeny during an early major phase 750660 ma and a late followup phase 650580 ma.
The term pan african thermotectonic event, or orogeny, has been applied by kennedy 1964, 1965 to a shieldwide series of metamorphic belts with ages in the range 450700 m. The panafrican orogenic cycle refers to a series of protracted late neoproterozoic orogenic events that resulted in the amalgamation of. Out of these, the grenvillian orogeny has long been regarded to be of minor nature in terms of globalscale orogenic episodes, whereas the pan african orogeny has been widely recognized in many continental fragments, although not in major parts of asia. The basis of african socialism journal of pan african. Over the past 50 years, the pan african orogeny has been extended to as much as 1050450 ma and recognized in other gondwanan continents where regional names such as brasiliano south america, adelaidean australian and bearmore antarctica have been applied.
Postcollisional panafrican granitoids and rare metal. African neoproterozoic mineral deposits and pan african. This east african orogen has long been considered the best exposed. Orogeny and reactivation to the west and southeast of the. Click on below buttons to start download a history of panafrican revolt by c.
Pt conditions of panafrican orogeny in southeastern nigeria. Geodynamic evolution of the panafrican orogenic belt. Damara orogeny mountain building event at the intersection of the congo and the kalahari cratons kibaran orogeny mountain building event in what is now africa. Completion of the nappe assembly around 620 ma is defined as the east african orogeny and was related to closure of the mozambique ocean.
During the pan african orogeny three deformational events had affected the otavi mountainland. Panafrican orogeny find, read and cite all the research you need on researchgate. Panafrican orogenic cycle is interesting in its own right. Our study of the 60,000 km 2 air massif, which comprises the southeastern extension of the tuareg shield in the niger republic, has identified three major displaced terranes. Pan african events culminated in the formation of the late neoproterozoic supercontinent gondwana figure 1. In cameroon the paleoproterozoic terrains have been reported mainly in the ntem complex, and also occur as relicts within the neoproterozoic formations1. The brasiliano pan african orogeny affected this terrane. Panafrican granulites of central dronning maud land and. The pan african orogeny resulted in the reactivation of the gneissic dahomeyan and the nigerian basement complex and the emplacement of a granite suite. Pan african orogeny series of major neoproterozoic orogenic events which related to the formation of the supercontinents gondwana and pannotia, neoproterozoic era 550 ma. The panafrican orogeny and the grenville orogeny are the largest known systems of orogenies on earth.
First direct evidence of panafrican orogeny associated. The pan african event in dronning maud land shows a collisional age of 610550 ma and an extensional stage at 530500 ma jacobs et al. The african continent preserves a long geological record that covers almost 75% of earths history. Pan african orogeny in the coastal region of ghana nature. Kola peninsula arcs are about 400 ma emplaced during continental collision in norwegian caledonides 300 km away darcs yellow have yielded 2. Measurement of panafrican strain in zaria precambrian. Improving geochronological framework of the panafrican. The late neoproterozoiccambrian pan african orogeny, which can be regarded as a diagnostic feature for reconstructing the gondwana supercontinent. As such, the pan african events are similar to the appalachian orogenic cycle extending from. Pan african orogeny, nigeria, obudu, upper amphibolitelower granulite facies introduction the precambrian basement terrane in nigeria is located in the neoproterozoic to early phanerozoic pan african transsaharan mobile belt that stretches from north africa to brazil, and has boundaries with the west african craton to the. Some of these veintype mineralisation have been remobilised after their formation, with the precipitation of massive cuag sulphides. The pan african thermotectonic event which took place between 750 ma 450 ma is believed to be the latest major orogenic event that affected the nigerian basement complex. Oct 01, 2014 for over 50 years the pan african orogeny has been recognized as a neoproterozoic tectonothermal episode affecting west africa 800550 ma.
The late precambrian to early paleozoic panafrican orogeny in ghana, togo, dahomey, and nigeria. The production of wealth, whether by primitive or modern methods, requires three things. The pan african was interpreted as a tectonothermal event, some 500 ma ago, during which a number of mobile belts formed, surrounding older cratons. The historical aspects of panafricanism apersonal chronicle. America then often called west gondwana by the panafrican. Before this, neoproterozoic to early cambrian rocks in eastern australia were formed in a passive margin and record dispersion of rodinia with consequent opening of the protopaci. The nature of the episode supports arguments that modern plate tectonic systems had begun by about. The nature and significance of the pan african orogeny and the relationships of alkaline ring complexes to orogenies. Pan african orogeny an overview sciencedirect topics. Geochronological evidence suggests that the prereactivation basement included rocks of birrimian age approximately 2000 m. Mesozoic removal of lithospheric mantle beneath the sierra nevada, california pdf. Tectonically, the rocks are classify as volcanic arc and syncollisional and possibly lateto postcollisional granitic rocks with respect to the pan african orogeny. Neoproterozoic cover occurs in both tectonostratigraphic terranes, but is more developed in the nptt. The pan african orogeny, which occurred at the proterozoicpalaeozoic boundary.
Geological activity focused along orogenic belts in africa during that time period is generally referred to as pan. Pan african orogeny 5 was a complete orogenic cycle and not merely a thermal event that caused isotopic changes. A structural analysis has been carried out along the southeast margin of the chambishinkana basin in the central african copperbelt, hosting the worldclass copper and cobalt cuco nkana orebody. For the next 350 ma this continent remained in existence and africa only experienced. The basement complex of nigeria is polycyclic and retains memories of events dating back to about 3000 m. Dubois and that is the attitude that all of uj had to him. West gondwana, represented by the pan african east.
African orogeny is ubiquitous in eastern south america and western africa and represents a protracted amalgamation of major crustal blocks along several mobile belts, giving rise to the accretion of gondwana after rodinia breakup almeida et al. Pdf early and late panafrican orogenies in the air. The late precambrian to early paleozoic panafrican. Oceans persisted after 620 ma between east antarctica, india, southern parts of the congotanzaniabangweulu cratons and the zimbabwekalahari craton. Other mineral components of the pt conditions of pan african orogeny in southeastern nigeria 363central european geology 51, 2008 table 1 representative modal composition of the studied rocks rock include orthopyroxene, titanite. A significant difference is that the appalachian orogenic cycle has long been. Some major ns nstrending strikeslip faults interiors zoback and zoback, 1989 trending late pan african fault zones and produce microscale to regional were rejuvenated during the palaeo the main nstrending fault zone scale structures hinze et al. The basis of african socialism journal of pan african studies. The panafrican orogeny was a series of major neoproterozoic orogenic events which related to the formation of the supercontinents gondwana and pannotia about 600 million years ago. The kombat ore deposit, otavi mountainland northern namibia.
It is obvious from the structural and metamorphic evidence that the pan african event reached the status of an orogeny in northwestern nigeria. The pan african orogeny was a series of major neoproterozoic orogenic events which related to the formation of the supercontinents gondwana and pannotia. The pegmatites occurring as minor rock unit within the study area are granitic in composition made up of large crystal of quartz and feldspathic materials. The pan african orogenic belt of hoggar, 800 km wide, represents an extremely tightened complex and composite mobile. Mar 06, 2020 pdf epub a history of panafrican revolt download if you are still wondering how to get free pdf epub of book a history of panafrican revolt by c. Thick mylonitic zones cut across this basement and are believed to have helped to localize the emplacement of the future equatorial fracture zones fail et al. Brazil and eastern antarctica has been interpreted as a network surrounding older cratons figure 1 and es. The study area is situated along the great ruaha river and within the mikumi national park in central tanzania where migmatitic gneisses and mafic to intermediate granulites are. God has given us the land, and it is from the land that we get the raw materials which we reshape to meet our needs. Panafrican orogeny in northern nigeria gsa bulletin.
See journal of african earth sciences 30, 589627 2000 structural, metamorphic and geochronological studies of the chewore inliers of the zambezi belt within the karoo age zambezi rift, allow recognition of a protracted multistage evolution, from the mesoproterozoic to culminating in the early palaeozoic pan african orogeny. The latea metacraton central hoggar, tuareg shield, algeria. However, the available zircon ages for the entire mb in east africa and madagascar also document that peak metamorphic conditions were. For over 50 years the pan african orogeny has been recognized as a neoproterozoic tectonothermal episode affecting west africa 800550 ma. The late precambrian to early paleozoic panafrican orogeny.
The pan african orogenic cycle is time equivalent with the cadomian orogeny in western and central europe and the baikalian in asia. The formation and evolution of africa from the archaean to present. The concept was then extended to the gondwana continents figure 1 although. Panafrican orogeny introduction the term pan african was coined bywqkennedy in 1964 on the basis of an assessment of available rbsr and kar ages in africa. Pdf hercynian compressional deformations of the ahnet. The neoproterozoic earth was shaped largely by the grenvillian and pan african orogenies. Don hallett, daniel clarklowes, in petroleum geology of libya second edition, 2016. Timing of deformation in the sarandi del yi shear zone. Pan african orogeny find, read and cite all the research you need on. Africa panafrican orogeny 5 the pan african orogenic cycle and locally migmatized andor mylonitized, either represent eastward extensions of the tanzania craton that were structurally reworked during pan african events or are separate crustal entities exotic blocks of unknown origin. The geometrically complex structural architecture is interpreted to have been generated during a single nesworiented compressional event, clearly linked to the pan african. Pan african orogeny series of major neoproterozoic orogenic events which related to the formation of the supercontinents gondwana and pannotia, neoproterozoic era 550 ma damara orogeny mountain building event at the intersection of the congo and the kalahari cratons. Jointing, fracturing, and faulting followed the orogeny, and a major northeastsouthwesttrending transcurrent fault system crosses the area.
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