GPR, GPS and Promax, applied to the detailed sedimentary architecture of tufa deposits

Fluvial tufa deposits consisting of tufa barrages separating large pools have been documented from the Lathkill valley England for some years, but their detailed architecture is rnainly conjectural based on widely-spaced boreholes. A systematic GPR survey of the Lathkill valley deposits has been conducted using a grid of 50 MHz GPR profilcs. with navigation provided by differential GPS. The data has been processed using the Prornax seismic processing system. The practical execution of the survey operation and the detail of the data processing using Promax are illustrated with appropriate exarnples from the large data set. The limiting factors on the penetration and resolution of the GPR data are discussed. The quality of the data is sufficient that considerable lithological information can be inferred from the sections using equivalent techniques to these of seismic stratigraphy. The interpretation is confirmed by continuously cored boreholes.