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

Abstract

This study investigates the presence of fossil in the Bimbila Limestones of the Oti Group of the Voltaian Basin of Ghana. Geological field mapping, petrographic and mineralogical analyses was used to investigate the organic matter (fossil) presence in the limestones. Results from the comprehensive study identified the Bimbila Limestones to have some microfolds and varve structures in outcrops as a result of marine depositional environment. Some are noted to be homogenous with no quartz or barite while others have quartz/barite. Petrographic analyses revealed that, the most abundant mineral is dolomite with other minerals present being micrite, chert, quartz, calcite, and iron oxide. Under the microscope, the Bimbila limestones were noted to be fossiliferous and hence providing inferred evidence of bioactivity preserved in the limestones. These fossils were inferred to be biogenic materials, possibly skeletal fossil and brachiopods remains probably derived from marine organisms.