Central and west african rare-Metal granitic pegmatites, related aplites, quartz veins and mineral deposits

1972 ◽  
Vol 7 (2) ◽  
pp. 202-216 ◽  
Author(s):  
N. Varlamoff
Keyword(s):  
Rare Metal ◽  
West African ◽  
Mineral Deposits ◽  
Granitic Pegmatites ◽  
Quartz Veins

Columbite-group minerals from rare-metal granitic pegmatites of the Sierra de San Luis,Argentina

2002 ◽  
Vol 14 (3) ◽  
pp. 627-636 ◽  
Author(s):  
Graciela M. Sosa ◽  
Marta S. Augsburger ◽  
José C. Pedregosa
Keyword(s):  
Rare Metal ◽  
Granitic Pegmatites ◽  
San Luis

scholarly journals Les Altérations Hydrothermales Associées À La Minéralisation Aurifère Du Gisement De Dougbafla (District d’Oumé-Hiré, Centre-Ouest De La Côte d’Ivoire)

2017 ◽  
Vol 13 (30) ◽  
pp. 108
Author(s):  
Ouattara Aboubakar Sidik ◽  
Coulibaly Yacouba ◽  
Kouadio Fossou J-L. H.
Keyword(s):  
Cote D'ivoire ◽  
Quartz Vein ◽  
Côte D’Ivoire ◽  
Gold Mineralization ◽  
West African ◽  
Cote D’Ivoire ◽  
West African Craton ◽  
Quartz Veins ◽  
Côte D'ivoire ◽  
The One

The Dougbafla gold deposit is located in the West-Central part of Côte d’Ivoire at about 240 km from Abidjan, on the Birimian greenstone belt of Fettèkro (West African craton). The lithologies of this deposit can be divided into three lithotectonic units which correspond to volcanic, sedimentary, and plutonic assemblages metamorphosed in the shale facies. Hydrothermalism, on the one hand, caused a pervasive alteration of the primary paragenesis marked by sericitic, silica, and carbonate alteration. On the other hand, it causes a vein alteration materialized by quartz veins. These hydrothermal alterations induced two types of gold mineralization in the Dougbafla deposit. These are: (i) disseminated gold and sulphide mineralization in the granophyre associated with sericite, silica and dolomite alteration in which no quartz vein has been reported; this type however is controlled by the intrusion of granophyre and (ii) a quartz vein mineralization controlled by deformation.

scholarly journals Hydrotermálny bastnäsit-(Ce) zo štôlne Elisabeth pri Gemerskej Polome (Slovenská republika)

2020 ◽  
Vol 28 (1) ◽  
pp. 1-8
Author(s):  
Martin Števko ◽  
Jiří Sejkora ◽  
Zdeněk Dolníček
Keyword(s):  
Infrared Spectra ◽  
Rare Metal ◽  
Coarse Grained ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
Quartz Veins ◽  
Hydrothermal Quartz ◽  
Magmatic Fluids ◽  
Type Granite ◽  
Pale Green

Bastnäsite-(Ce), ideally CeCO3F, was recently found at the dumps of the Elisabeth adit near Gemerská Poloma, Rožňava Co., Košice Region, eastern Slovakia. It forms orange-brown aggregates up to 2 × 1 cm with vitreous to greasy lustre, which occur in the hydrothermal quartz veins crosscutting the coarse-grained, porphyritic rare metal S-type granite. Bastnäsite-(Ce) is closely associated with white, pale-green to purple fluorite, siderite and minor pyrite. It is hexagonal, space group P-62c with refined unit-cell parameters: a 7.1354(1) Å, c 9.7954(2) Å and V 431.90(1) Å3. The empirical formula of bastnäsite-(Ce) from the Gemerská Poloma based on sum of all cations = 1 apfu is (Ce0.49 La0.22Nd0.15Pr0.05Sm0.03Th0.02Ca0.02Gd0.01Y0.01)Σ1.00(CO3)1.00F0.83(OH)0.17. The Raman and infrared spectra of bastnäsite-(Ce) as well as tentative assignment of observed bands are given in this paper. Bastnäsite-(Ce) and associated minerals were formed from the early-hydrothermal post-magmatic fluids related to the adjacent granite.

scholarly journals Silica enrichment, graphic granite and aquamarine growth: a new exploration guide

2002 ◽  
Vol 74 (3) ◽  
pp. 533-538
Author(s):  
A. BHASKARA RAO
Keyword(s):  
Granitic Pegmatite ◽  
Potash Feldspar ◽  
Granitic Pegmatites ◽  
Quartz Veins ◽  
Rock Types ◽  
Eutectic Crystallization ◽  
State Present ◽  
Through Diffusion ◽  
Texture Structure ◽  
Definition Of

Granitic pegmatites are traditionally known to contain graphic, perthitic and myrmekitic intergrowths related to quartz and K- and Na- feldspars. They are further considered to characterise the pegmatite types distinguishing them from the granites and other related plutonic rock types. Graphic granite is accepted also as a synonym to granitic pegmatite. Systematic studies, by the author and colleagues, on the granitic pegmatite gem deposits have permitted the definition of two aquamarine gem provinces in ENE Brazil, one in the NeoProterozoic and the other in the Archaean sequences. Potash feldspars in the pegmatites in the former show perthitic intergrowths, whereas in the latter graphic intergrowth dominates with anomalously coarse centimetric quartz along the cleavages of K-feldspar. Several granitic pegmatites hosted in Archaean complex, in Lages Pintadas Aquamarine Province, Santa Cruz, RN State, present this texture-structure. Graphic intergrowth is attributed to the eutectic crystallization, succeeded by hydrothermal fluids with silica enrichment permitting the growth through diffusion and nucleation of quartz and along cleavages of potash feldspar. In the Archaean terrain, the abundance of recycled chert forming metapsammitic migmatites traversed by numerous quartz veins and coarse graphic granites, has contributed to the growth of beryl and also the aquamarines.

scholarly journals Compilation of West African mineral deposits: Spatial distribution and mineral endowment

2016 ◽  
Vol 274 ◽  
pp. 61-81 ◽  
Author(s):  
Vanessa Markwitz ◽  
Kim A.A. Hein ◽  
John Miller
Keyword(s):  
Spatial Distribution ◽  
West African ◽  
Mineral Deposits
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