UPb age constraints on deposition and provenance of Birimian and gold-bearing Tarkwaian sediments in Ghana, West Africa

Davis, Donald W.; Hirdes, W.; Schaltegger, Urs; Nunoo, E.A.

doi:10.1016/0301-9268(94)90006-x

Cited by 195 publications

(95 citation statements)

References 29 publications

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“…Le policyclisme de l'Eburnéen est adopté par Lemoine (1985Lemoine ( , 1988 (Leube et al, 1990 ;Hirdes et al, 1992 ;Davis et al, 1994) (Vidal et Alric, 1994 ;Delor et al, 1995 c).…”

Section: -Les Flatsunclassified

Facteurs paramètres dynamique de distribution et genèse des dépôts de columbo-tantalite d Issia centre-ouest de la Côte d Ivoire

Allou

2005

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(1) les trois principaux granites de la région ont été produits par des processus profonds ayant généré une fusion partielle de la croûte, (2) ils ont été formés par cristallisation fractionnée pendant la période syn-à tardi-D2 de l'orogenèse Ébuméenne, et ( Du point de vue de l'évolution supergène, il est montré que les processus naturels superficiels dans les milieux tropicaux humides ne génèrent ni croissance, ni changements chimiques dans les minéraux de Nb-Ta. Toutefois, même si la qualité chimique du minéral est préservée, la qualité physique, quant à elle, se dégrade progressivement des zones éluviales aux zones alluviales sous l'effet des corrosions mécaniques. Columbite-tantalite deposits in humid tropical areas are generally supergene deposits associated with gravel. These deposits have been poorly studied and are mined only by small developers. This is attributed, on one hand to the small scale and the short life of the individual deposits and, on the other hand to the great thickness of the alteration overburden in zones of high concentration.This study has a triple objective: (1) establish a geodynamic model for the Issia columbite-tantalite primary mineralization and associated minerals; (2) define the factors controlling the secondary redistribution of the mineralization in detrital environments through integrating pedo-geomorphologic and geostatistical studies; and (3) determine the mineralogical species of niobium, tantalum and other associated ore minerals.The study area includes three granitic massifs intruding sedimentary rocks: the oriented two-mica granite (Lobo granite), the oriented muscovite granite (Bitapia granite) and the non-oriented, porphyritic muscovite granite (Issia granite). Field observations and whole rock analyses show that: (1) the three main granites of the region are produced by deep seated processes which generated partial melting of the crust; (2) they were formed by fractional crystallization during the syn to late-D2 period of the Ebumean orogenesis; and (3) the Issia type granite was the last to be formed at 2106±78 My. Variographic analyses and kriging give satisfactory results for the columbite-tantalite supergene deposits prospecting. This approach defines prospecting grids for the deposit types in the studied areas and it brings to evidence very weak variation on a small scale and a great continuity of the mineralization following the direction of pegmatites. The kriging results indicate that lognormal kriging is the best tool for estimation of the reserves because this method better minimizes the bias and the variance of estimation. VIThis study has a direct implication for the prospecting of columbite-tantalite detrital deposits in Issia as well as at the global scale. Indeed, it shows that in a columbite-tantalite pegmatite environment located in humid tropical areas, eluvial and colluvial gravels are more favourable to mining than alluvial gravels. Enfin, je remercie tout le personnel du module des sciences de la terre, les professeurs, les techniciens, les é...

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“…Le policyclisme de l'Eburnéen est adopté par Lemoine (1985Lemoine ( , 1988 (Leube et al, 1990 ;Hirdes et al, 1992 ;Davis et al, 1994) (Vidal et Alric, 1994 ;Delor et al, 1995 c).…”

Section: -Les Flatsunclassified

Facteurs paramètres dynamique de distribution et genèse des dépôts de columbo-tantalite d Issia centre-ouest de la Côte d Ivoire

Allou

2005

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“…Mü cke et al Master et al (1993), Davis et al (1994), Hirdes and Davis (1998) Lukoshi Complex, Zaire…”

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confidence: 99%

Chemostratigraphy of Paleoproterozoic carbonate successions of the Wyoming Craton: tectonic forcing of biogeochemical change?

Bekker

2003

Precambrian Research

140

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“…From the bottom to the top it consists of: (1) polymict conglomerate with pebbles of phyllite, granite, felsic and mafic lavas, pyroclastic rocks, quartz, and chert; (2) sandstone and auriferous monomict conglomerate with quartz pebbles; (3) phyllite and sandstone. These rocks were deposited in elongated graben formed over the Birimian belts and record continental to mature fluviatile and deltaic environmental conditions, and they are locally associated with pyroclastic flows and rhyolites, and with dolerite and gabbro sills (Davis et al 1994;Feybesse & Milési 1994;Ledru et al 1994). Most of the detrital zircons of this sequence have ages in the range of 2185 -2155 Ma, with subordinate ages of 2245 Ma, 2132 Ma and 2124 Ma (Davis et al 1994;Bossière et al 1996), and the maximum age of sedimentation would be bracketed by intrusion relationships as between 2080 and 1960 Ma (Ledru et al 1994;Bossière et al 1996).…”

Section: The Tarkwa Sedimentary Sequencementioning

confidence: 99%

“…These rocks were deposited in elongated graben formed over the Birimian belts and record continental to mature fluviatile and deltaic environmental conditions, and they are locally associated with pyroclastic flows and rhyolites, and with dolerite and gabbro sills (Davis et al 1994;Feybesse & Milési 1994;Ledru et al 1994). Most of the detrital zircons of this sequence have ages in the range of 2185 -2155 Ma, with subordinate ages of 2245 Ma, 2132 Ma and 2124 Ma (Davis et al 1994;Bossière et al 1996), and the maximum age of sedimentation would be bracketed by intrusion relationships as between 2080 and 1960 Ma (Ledru et al 1994;Bossière et al 1996). There is a certain agreement in that both the Birimian and Tarkwa successions have been deformed together during the final stages of the Palaeoproterozoic Eburnian orogeny (Davis et al 1994;Ledru et al 1994).…”

Section: The Tarkwa Sedimentary Sequencementioning

confidence: 99%

São Luís Craton and Gurupi Belt (Brazil): possible links with the West African Craton and surrounding Pan-African belts

Klein

Moura

2008

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The São Luís Craton and the Palaeoproterozoic basement rocks of the Neoproterozoic Gurupi Belt in northern Brazil are part of an orogen having an early accretionary phase at 2240-2150 Ma and a late collisional phase at 2080 + 20 Ma. Geological, geochronological and isotopic evidence, along with palaeogeographic reconstructions, strongly suggest that these Brazilian terrains were contiguous with the West African Craton in Palaeoproterozoic times, and that this landmass apparently survived subsequent continental break-up until its incorporation in Rodinia.The Gurupi Belt is an orogen developed in the southern margin of the West African-São Luís Craton at c. 750-550 Ma, after the break up of Rodinia. Factors such as present-day and possible past geographical positions, the timing of a few well-characterized events, the structural polarity and internal structure of the belt, in addition to other indirect evidence, all favour correlation between the Gurupi Belt and other Brasiliano/Pan-African belts, especially the Médio Coreaú domain of the Borborema Province and the Trans-Saharan Belt of Africa, despite the lack of proven physical links between them. These Neoproterozoic belts are part of the branched system of orogens associated with amalgamation of the Amazonian, West Africa-São Luís, São Francisco and other cratons and minor continental blocks into the West Gondwana supercontinent.

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UPb age constraints on deposition and provenance of Birimian and gold-bearing Tarkwaian sediments in Ghana, West Africa

Cited by 195 publications

References 29 publications

Facteurs paramètres dynamique de distribution et genèse des dépôts de columbo-tantalite d Issia centre-ouest de la Côte d Ivoire

Facteurs paramètres dynamique de distribution et genèse des dépôts de columbo-tantalite d Issia centre-ouest de la Côte d Ivoire

Chemostratigraphy of Paleoproterozoic carbonate successions of the Wyoming Craton: tectonic forcing of biogeochemical change?

São Luís Craton and Gurupi Belt (Brazil): possible links with the West African Craton and surrounding Pan-African belts

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