Ghana falls mostly within the west african craton which stabilised in the early proterozoic 2000 ma during the eburnean orogeny. T1 4d evolution of the orogenic gold district of siguiri, guinea west africa au lebrun, erwann ocellian. Deformation mechanism changed from d1 pure shear dominated compression, to d2 simple shear dominated transpression. Although diachronous across west africa, the eburnean orogeny is typically indicated to have been initiated at ca. Orogens develop while a continental plate is crumpled and thickened to form mountain ranges, and involve a great range of geological processes collectively called orogenesis. A new metamorphic constraint for the eburnean orogeny from. The major d2 related structures is the regional thrust striking ns over an area of 12 km long and 3 km wide and within which corridors all siguiri gold mine open pits are located. If you would like to participate, you can choose to edit this article, or visit the project page for more information. The alpinehimalayan belt is a young orogen, a continuous belt of mesozoic and cenozoic deformation stretching from spain to new zealand. Jun 01, 2015 read petrological and geochronological constraints on lower crust exhumation during paleoproterozoic eburnean orogeny, nw ghana, west african craton, journal of metamorphic geology on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Fluid pressuredominated orogenic gold mineralization.
The eburnean orogeny early proterozoic, 2000ma2500ma iii. Episodic collisional orogenesis and lower crust exhumation during the palaeoproterozoic eburnean orogeny. To better understand the role boundary conditions and the. The new data set challenges the interpretation that metamorphic breaks in the west african craton are due to diachronous birimian basins overlying a gneissic basement. The eburnean orogeny in africa results from the continental collision between the san francisco and congolian cratons. Episodic collisional orogenesis and lower crust exhumation. The congo shield is a central african large landmass with several archean nuclei welded during the eburnean. During the eburnean orogeny the nesw trending d2 thrust fault were reactivated as sinistral strikeslip faults as a result of the. Pdf the 2ga eburnean orogeny in gabon and the opening. Precambrian research 123 2003 4765 a new metamorphic constraint for the eburnean orogeny from paleoproterozoic formations of the man shield aribinda.
It suggests that the lower crust was exhumed along reverse, normal and transcurrent shear zones and juxtaposed against shallow crustal slices during the eburnean orogeny. Timing and kinematics of eburnean tectonics in the central. The kibaran orogeny mid proterozoic, 1100ma 2000ma iv. Stub this article has been rated as stubclass on the projects quality scale. Of all the above, the eburnean and the panafrican are major events which modified the precambrian geology of nigeria including the southwestern nigerian basement complex. Eburnean orogeny is part of wikiproject geology, an attempt at creating a standardized, informative, comprehensive and easytouse geology resource. Pdf juvenile paleoproterozoic crust evolution during the. The origin and hydrothermal mobilization of carbonaceous. Regional scale system geometry controlled by coaxial shortening of. The different stages of this orogeny in gabon are described from the initial rifting of the archean continent with the crustal melting producing preeburnean migmatites at 2450 ma, the opening of an ocean. Juvenile paleoproterozoic crust evolution during the.
The eburnean orogeny, or eburnean cycle was a series of tectonic, metamorphic and plutonic events in what is now west africa during the paleoproterozoic era about 22002000 million years ago. Northern victoria land antarctica is made up of three terranes of cambrianordovician rocks. Pdf the 2ga eburnean orogeny in gabon and the opening of. View the article pdf and any associated supplements and figures for a period of 48 hours. Read revised eburnean geodynamic evolution of the goldrich southern ashanti belt, ghana, with new field and geophysical evidence of pretarkwaian deformations, precambrian research on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
Highgrade metamorphic domains are separated from lowgrade greenstone belts by highstrain zones, including early thrusts, extensional detachments and latestage strikeslip shear zones. Orogeny simple english wikipedia, the free encyclopedia. The following is a list of known orogenies organised by continent, starting with the oldest at the top. The highgrade rocks presumably exhumed along the sinistral shear zones during the d2 enewsw transtension 2073 ma.
The different stages of this orogeny in gabon are described from the initial rifting of the archean continent with the crustal melting producing pre eburnean migmatites at 2450 ma, the opening of an ocean. There was change in compressional regime from nwse to ns during the d4d5 event and. Intrusionrelated affinity and orogenic gold overprint at. Three principal deformation events d1d3 can be distinguished in the study area. Juvenile paleoproterozoic crust evolution during the eburnean orogeny similar to 2. The exhumation along the kenyase and ketesso shear zones in. The kuunga orogeny from swahili, to unite is an orogeny that occurred in southeast africa during the ediacaran and cambrian. An orogeny is an event that leads to both structural deformation and compositional differentiation of the earths lithosphere crust and uppermost mantle at convergent plate margins. This orogeny also stabilised the zaire craton and affected vast parts of western africa and neighbouring regions in south america that were conterminous with the eburnean tectonothermal province. Outside south africa, the west african craton is the second largest region in. Max vidal, charles gumiaux, florence cagnard, andr e pouclet, g. The kintinian olistostrome highlights the fundamental structures that control the location of the siguiri gold district and was deposited during the onset of tectonic activity associated with the early stages of orogenic contraction during the eburnean orogeny.
The study area is dominated by three metavolcanic and metasedimentary packages known as the sefwi group, the kumasi group birimian and the tarkwa group tarkwaian that were intruded by abundant ttg granitoids during the eoeburnean and eburnean phases of an event termed the eburnean orogeny. Petrological and geochronological constraints on lower. Nov 01, 2011 read juvenile paleoproterozoic crust evolution during the eburnean orogeny. Pdf the eburnean orogeny in africa results from the continental collision between the san francisco and congolian. Nov 27, 2018 highgrade amphibolitegranulite facies tectonometamorphic domains in the sefwi terrane of ghana are separated from adjacent lowergrade greenschist facies greenstone belts by two main shear zones. Juvenile paleoproterozoic crust evolution during the eburnean. Summary diagram of d 2 and d 3 structural data from domains within the study area. Orogeny is the primary mechanism by which mountains are built on continents. New evidences for an early birimian evolution in the west.
These formations are called birimian in west africa. Evolution of a paleoproterozoic weak type orogeny in the west. Read a new metamorphic constraint for the eburnean orogeny from paleoproterozoic formations of the man shield aribinda and tampelga countries, burkina faso, precambrian research on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Discussion the eburnean orogeny corresponds to a major crust forming event defined by the formation of paleoproterozoic supracrustal rocks and associated synvolcanic and syn to late kinematic intrusive rocks. In the ns trending structures, there is eastnortheast shortening and northnorthwest extension. Download fulltext pdf the 2ga eburnean orogeny in gabon and the opening of the francevillian intracratonic basins. Petrological and geochronological constraints on lower crust exhumation during paleoproterozoic eburnean orogeny, nw ghana, west. Petrological and geochronological constraints on lower crust. May 15, 2019 the bonikro gold deposit and satellite hire open pits are located at the southern tip of the oumefettekro granitegreenstone belt in cote divoire. Highlights a new geotectonic model of juvenile crust formation and evolution during the eburnean orogeny. Avanashilinga prabhu marked it as toread oct 22, harshvardhan chavan marked it as toread oct 02, please use a. It takes place when two tectonic plates come together. An orogen or orogenic belt develops when a continental plate crumples and is pushed upwards to form one or more mountain ranges. Geology, geodynamics and orogenic gold prospectivity.
Pdf a new metamorphic constraint for the eburnean orogeny from. The eburnean orogeny was not strongly rejuvenated during the panafrican thermotectonic events 6 0. Pdf episodic collisional orogenesis and lower crust exhumation. The first and third columns plot s 2 planes and l 2 and f 2 poles to highlight the coaxial, shallowplunging relationship of l 2 and f 2. The eburnean orogeny, or eburnean cycle was a series of tectonic, metamorphic and plutonic. Nevadan orogeny, mountainbuilding event in western north america that started in the late jurassic epoch about 156 million years ago. A new metamorphic constraint for the eburnean orogeny from paleoproterozoic formations of the man shield aribinda and tampelga countries, burkina faso. Rather, the kheisian fabric is now dated as younger than 1. This event is generally considered to be the first significant phase of cordilleran mountain building, which continued into the early cretaceous epoch.
Panafrican dahomeyide orogenic belt figures 1 and 2. Evolution of a paleoproterozoic weak type orogeny in the. Regional geology the paleoproterozoic birimian volcanosedimentary belts with associated granitoids belonging to the baoulemoss domain of the west african craton formed between 2250 and 1980 ma feybesse et al. Unlimited viewing of the articlechapter pdf and any associated supplements and figures. Eburnean orogeny, a series of major tectonic events around 2100 ma. During this period the birimian domain in west africa was established and structured. The congo craton, covered by the palaeozoictorecent congo basin, is an ancient. Composed of three separate orogenic belts damara, zambesi, and lurio that are slightly younger than the east african orogeny, the kuunga orogeny documents the collision between north and south gondwana, or what is today dronning maud land in antarctica and northern. Panafrican paleostresses and reactivation of the eburnean. Evolution of the namaquanatal belt, southern africa a. Pdf new constraints on the architecture, deformation sequence and tectonic evolution of the sparsely exposed.
They stabilised during the transamazonian orogeny and eburnean orogeny and have. The first mineralization stage is hosted by faultfill veins along conjugate ene. Pdf episodic collisional orogenesis and lower crust. Eburnean orogeny, nw ghana, west african craton wiley online. Pdf the 2ga eburnean orogeny in gabon and the opening of the. N2 the west african craton hosts some of the biggest gold deposits in the world such as obuasi, sadiola, morila or siguiri. The advent of plate tectonics 35 years ago provided an explanation for the largescale plate kinematics associated with alpinehimalayan orogeny. This domain which is geologically distinct to congo craton. During the eburnean orogeny the nesw trending d2 thrust fault were reactivated as sinistral strikeslip faults as a result of the d4d5 deformation events.
Eburnean definition of eburnean by the free dictionary. The eburnean orogeny was not strongly rejuvenated during the panafrican thermotectonic events 6 0 0 5 0 ma. Intrusionrelated affinity and orogenic gold overprint at the. May 20, 2003 read a new metamorphic constraint for the eburnean orogeny from paleoproterozoic formations of the man shield aribinda and tampelga countries, burkina faso, precambrian research on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. The organization of this article is along presentday continents that do not necessarily reflect the geography contemporary to the orogenies. Revised eburnean geodynamic evolution of the goldrich. Juvenile paleoproterozoic crust evolution during the eburnean orogeny. The study area is located in the interference zone between ns and nesw trending cratonscale shear zones, formed during the eburnean orogeny 2. The dominant structural nucleus was formed during the paleoproterozoic eburnean orogeny. Eburnean democratic bloc, a splinter group of the democratic party of cote divoire formed in 1949. During this orogeny, the siguiri district sedimentary rocks were affected by four deformation events. Evolution of a paleoproterozoic weak type orogeny in the west african craton ivory coast. Backarc cambroordovician ross orogeny northern victoria land. We have investigated three greenstone belts boromo, hounde, and banfora and associated granitoid terrains, which form part of the eburnean orogen.
Evidence from the sefwi greenstone belt, west african craton. The birimian terrains in the wac represent juvenile crust without any influence of surrounding archean. Highgrade amphibolitegranulite facies tectonometamorphic domains in the sefwi terrane of ghana are separated from adjacent lowergrade greenschist facies greenstone belts by two main shear zones. A new metamorphic constraint for the eburnean orogeny from paleoproterozoic formations of the man shield aribinda and. Rb sr systematics dating back to the eburnean orogeny 22001680 ma. Both oreforming stages occurred during protracted ewdirected shortening associated with the eburnean orogeny.
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