Ground-penetrating radar (GPR) and fluvial placers in a tropical setting, Maple Creek, Guyana

This project examines the application of surficial stratigraphy and ground penetrating radar (GPR) to investigate the organization of a fluvial valley-fill in a tropical setting. Fieldwork was conducted at Vannessa Ventures Ltd.'s Maple Creek diamond and gold placer property in the Potaro Mining District, Guyana, South America. GPR provided exceptional depth penetration (>70 m) and high quality imagery of the fluvial architecture of a buried valley. The reflector representing the bedrock-sediment interface was identified in the cross-sections, allowing for the generation of three-dimensional GIS models of the paleovalley. A local stratigraphy was established and is correlative in part with the White Sand Formation of the Corentyne Series. The White Sand Formation has traditionally been assigned a marine origin, however this work suggests the appearance of the white sand is the result of diagenesis and a chemical weathering model for alluvium is proposed. Successful test pitting demonstrated the diamond and gold placer potential of the Maple Creek valley-fill. This study showed that sedimentology, geophysics and GIS are valuable tools in placer exploration.