Ground penetrating radar imaging of cap rock, caliche and carbonate strata

Field experiments show ground penetrating radar (GPR) can be used to image shallow carbonate stratigraphy effectively in a variety of settings. In sou th Florida, the position and structure of cap rock cover on limestone can b e an important control on surface water flow and vegetation, but larger sca le outcrops (tens of meters) of cap rock are sparse. GPR mapping through so uth Florida prairie, cypress swamp and hardwood hammock resolves variations in thickness and structure of cap rock to similar to 3 m and holds the pot ential to test theories for cap rock-vegetation relationships. In other set tings, carbonate strata are mapped to test models for the formation of loca l structural anomalies. A test of GPR imaging capabilities on an arid calic he (calcrete) horizon in southeastern Nevada shows depth penetration to sim ilar to 2 m with resolution of the base of caliche. GPR profiling also succ eeds in resolving more deeply buried (similar to 5 m) limestone discontinui ty surfaces that record subaerial exposure in south Florida. (C) 2000 Elsev ier Science B.V. All rights reserved.