Lithostructural and Petrochemical Survey of Djarkadougou Gold Prospect (South West Burkina Faso / West Africa)

Abstract

The Djarkadougou gold prospect is located on the Birimian greenstone belt of the Houndé exploration permit held by the company Orezone Inc. The permit is at 275 km far from the capital Ouagadougou south-western Burkina Faso, West Africa. This area is based on sheared and metamorphosed greenschist facies rocks. Metamorphism locally reaches to the amphibolite facies around intrusions. There are two major lithological units whose interface is marked by a NW-SE trending shear corridor: an unit of andesite-basaltic rocks of andesitic breccias in the East and volcaniclastic and sedimentary unit composed flows, tuffs and felsic to mafic breccia, interbedded volcano-sedimentary rocks. All this together is intruded by plutonic rocks, and various felsic to mafic dykes. These rocks have undergone ductile to brittle heterogeneous deformations and hydrothermal alteration sericite ±carbonate ±quartz±sulphide within deformation corridors. The rocks of the East and West domains affected by three phases of brittle-ductile deformation (D1, D2, and D3) and the meteoric alteration is systematic in superficial facies of Djarakadougou core drilling.Geochemical analysis shows a tholeiitic to calc-alkaline volcanic serie characteristic a bimodal volcanism. The spectra of normalized REE chondrites are generally flat and constant reminding those of N-MORB basalt. The chemical compositions of andesite and basalt are deferred on several discrimination diagrams especially Th / Yb -Nb / Yb and 2 Nb -Zr / 4 -Y show that andesites and basalts of the prospect are issued in geotectonic setting of volcanism preponderant arc.

Geochemical and Geodynamic Constrain of Tholeiitic Volcanism and Related Intrusions in the Kampti Gold District, Southwest Burkina Faso: Implication for Mineral Exploration

“…It comprises at the base a sequence of tholeiitic mafic and calc-alkaline volcanic which crops in either side of the belt margin and scarred as NE elongated strips of mountain ( Figure 2a). The volcanic sequence is surmounted by pelitic metasediment (Arnould, 1950(Arnould, et 1958Ludtke et al, 1998;Marcelin, 1971) and limited sandy and conglomeratic unconformity (Bonkougou, 1994;Koffi et al, 2017). The latter sequence is suggested deriving from the former volcanic rocks by proximal erosion.…”

“…Albite is interpreted to not be the primary composition of the volcanic, but part of the low grade metamorphic process. Primary minerals (feldspar, amphibole +/-pyroxene) of the plutono-volcanics has been destabilized in albite, ouralite, epidote, ripidolite type chlorite and carbonates similar to other places described in the houndé belt (Lüdtke et al, 1998(Lüdtke et al, ., 1998Nanema et al, 2016;Koffi et al, 2017).…”