Optical petrography and XRD as tools for heavy mineral studies: a case of the Tamale and Oti Groups, Voltaian Supergroup, Ghana

Optical petrography and X-ray Diffraction (XRD) are essential techniques for analysing the mineralogical and textural characteristics of heavy minerals in sedimentary formations. This study applies optical petrography and XRD to the Tamale and Oti Groups within the Voltaian Supergroup of Ghana to enhance understanding of their provenance, diagenetic history, and economic potential. Optical petrography enables detailed characterization of mineral grains, identifying key features such as zoning, inclusions, and alteration patterns under transmitted light. XRD complements this by determining crystalline phases and quantifying mineral compositions, especially in fine-grained sediments where traditional microscopic methods face limitations.

Preliminary results indicate a diverse heavy mineral assemblage, including zircon, tourmaline, rutile, garnet, phosphates, glauconite, micas, apatite, spinel and monazite, suggesting contributions from both igneous and metamorphic source terrains. Petrographic analysis reveals minimal grain morphological variations for stable minerals like zircons and post-depositional modifications, including dissolution features. XRD further confirms the presence of stable heavy minerals, reinforcing their potential as provenance indicators. These findings contribute to broader sedimentary petrology and geochemical studies, offering insights into the depositional environment and tectonic evolution of the Voltaian Basin.

By integrating optical petrography and XRD, this study advances interdisciplinary approaches in geoscience, supporting sustainable resource exploration and development in Ghana. The results have implications for mineral exploration, environmental assessments, and basin evolution models, reinforcing the significance of advanced analytical techniques in sedimentary research.