Tarkwaian Deposits of the Birimian Belt of Houndé: Petrological, Structural and Geochemical Study (Burkina-Faso, West Africa)

Abstract

The Tarkwaian deposits of the Birimian belt of Houndé are located in the Baoule-Mossi Paleoproterozoic area of the West African Craton. The sedimentary units consist of sandstone heterometric pelitic feldspthic sandstone with locally interbedded breccias, puddings and polygenic conglomerates. Lithic pebbles and macroscopic fragments that are similar to vein type originated quart castings and andesitic-dacitic projections, felsic sub-volcanic rocks evolving from microdioritic to microgranite composition are detected in terrigenous sediments. The volcanic packages form a linear strip composed of basic to intermediate rocks and andesitic to dacitic volcaniclastites. The contacts between these units are not clearly exposed but the different facies between the polygenic conglomerates and sandstones show discordant tectonic contacts with the Tarkwaian and the Birimian. The geochemical nature of these Tarkwaian formations is strongly influenced by the relative decline of the dominant quartz of feldspars and phyllites. The improperly classified and immature feldspathic sandstones show context affinities of island arc probably dictated by Birimian lithic products. Sedimentologically, the cross-bedded stratification and the predominance of sandstone terrigenous lands indicate a deposition in a fluvio-deltaic hydrodynamic setting along intermontane Birimian rift. The similarities between these Tarkwaian formations and the typical Tarkwaian of the Tarkwa basin in Ghana are probably limited to petrographic and not stratigraphic aspects, which lead to likening them to flyschoïd or molassic tardi Birimian deposits.

Gold Mineralisation in the Intiédougou Prospect (Diébougou District) in Southwest Burkina Faso, West African Craton

“…This belt has been, and continues to be, the subject of several exploration campaigns. The Intiédougou target comprises a unit of Tarkwaïan-type clastic sediments sandwiched within volcanic and volcano-sedimentary rocks of andesitic flow to breccia and tuf ( [7] [8] [9] and [10]). The volcanic and sedimentary units are intruded by circumscribed granitic massifs attributed to the Birimian (Koffi et al, 2018), with ages between 2170 Ma and 1500 Ma.…”

Fossil evidence in the Bimbila Limestones of the Oti Group in the Voltaian Basin of Ghana

“…However, of the four sedimentary basins, the Voltaian basin is yet to see detail investigation into fossils and source rocks characteristics in the basin. The hydrocarbon potential of the other three offshore sedimentary basins however have been studied leading to exploration work and discoveries in some of these basins (Leube et al, 1990;Milési et al, 1991;Eisenlohr and Hirdes, 1992;Brownfield and Charpentier, 2006;Koffi et al, 2016;Smith et al, 2016).…”

Evaluation of porosity and permeability of sandstones within the Oti Group of the Volta Basin using petrophysical and petrographic techniques

“…Among the four sedimentary basins in Ghana (Tano Basin, Keta-Accra Basin, Saltpond Basin and Volta Basin), the least probed into for information on its hydrocarbon prospectivity is the Volta Basin. Unlike the Volta Basin, hydrocarbon exploration efforts were intensified on the other basins and their hydrocarbon prospectivity studied (Chudasama et al, 2016;Eisenlohr and Hirdes, 1992;Koffi et al, 2016;Leube et al, 1990;Milési et al, 1991;Smith et al, 2016).…”