Abstract

Ground-penetrating radar (GPR) can image near-surface features with
high (submeter)  resolution.
A field feasibility test over a collapsed-paleocave system in
the Lower Ordovician Ellenburger dolomites in central Texas shows the
ability to image both large (tens of meters) and small (submeter) scale 
features.  2-D GPR profiles were recorded along the top of quarry 
walls to image features
displayed in the walls.  GPR data collected over the transition 
between the dipping, stratified host rock and the brecciated cave
fill show the curved contact of the cave wall and roof, 
fine- to medium-sized chaotic breccia, and tension fractures 
paralleling the cave wall.  GPR data collected over a zone of 
megablocks that resulted from massive cave roof collapse outline blocks
that range in size from a few meters to over 6 meters.  The features in
the GPR data lines correspond well with those noted in the adjacent 
quarry faces. This demonstrates potential feasibility 
for detailed study of carbonate facies and features from GPR data and
suggests 3-D surveys as a desireable next step. Potential 
applications include 3-D characterization of analogs of 
collapsed-paleocave hydrocarbon reservoirs.