Integration of seismic and sedimentological methods for analysis of Quaternary alluvial depositional systems

Abstract

Due to the high potential of unconsolidated sedimentary bodies to form aquifers and reservoirs, an identification of their exact geometry and location is of great importance. Current conceptual models of these bodies are often developed using scattered data from hydrogeological wells. More reliable results can be achieved by application of methods that can provide continuous subsurface record of the actual geological situation in the investigated area. In this article, a combination of two different approaches is used on a case study of alluvial Quaternary sediments from the East Slovakian Basin, including the discussion how these methods contribute to the final geological interpretation. First, a sedimentological analysis was performed with the use of data acquired from auger drilled hydrogeological wells, which enabled identification of depositional processes, depositional systems and the possible source areas. Due to the shallow depth of the studied area, a second approach based on the geophysical measurement using seismic refraction and tomography was applied. This method provided information mainly about the geometry of these systems, the position of the sediments within them and highlighted where the main changes in the sediment texture and composition occurred. Integration of both methods allows us to obtain a more precise image of the subsurface, which contributes to a better understanding and prediction of the occurring sediments in the studied area.