Sedimentary Architecture Revealed through High Resolution GPR Investigations

Abstract

Quaternary gravel-bed deposits form widespread valley-aquifer systems (Kostic, 2007) in many parts of the world. Particularly, in many regions of Romania, these phreatic aquifers are often used by the rural communities as the main potable water source. In unconsolidated sediments the variation of the hydraulic parameters is controlled mainly by the lithological heterogeneities. These are a product of the depositional and transport processes which took place within the fluvial systems (Kostic, 2007). Integrated interpretation of the results obtained through sedimentological analysis and high resolution geophysical methods such as Ground Penetrating Radar (GPR) can offer us the possibility of emphasizing these heterogeneities within the fluvial deposits. Knowing the sedimentary architecture and the internal heterogeneities of the gravel bed formations which host the phreatic aquifer, we can be lead to a better understanding of the groundwater dynamic. The integrated interpretation of both the sedimentological and geophysical data highlighted five major types of lithofacies and also five types of depositional elements. These depositional elements play a key role in the groundwater dynamic. Therefore, their characterization can lead to a better understanding of the groundwater flow and can be very significant in hydrogeological modelling.