Ground penetrating radar images of unexposed climbing dune-forms in the Ubehebe hydrovolcanic field (Death Valley, California)

Ground penetrating radar surveys were conducted in the Ubehebe hydrovolcani c field (Death Valley, California) using 900 MHz antennae, which allowed hi gh-resolution images of the subsurface. The surveys were intended to study the lateral facies variation of subsurface sequences in base surge deposits and were run along a flow direction radial to the Ubehebe Crater. The grou nd penetrating radar imaged deposits that would otherwise be difficult to s tudy because they are in an area with very few outcrops. In particular, the radar profiles show the presence of wavy reflections from relatively proxi mal to intermediate positions which become increasingly less wavy and more plane-parallel in distal locations. The wavy reflections have been interpre ted as ground penetrating radar images of subsurface trains of climbing dun e-forms, whose size decreases downflow. A climbing dune-form exposed inside a trench in correspondence to a crest of wavy reflections, confirms this i nterpretation. These results show that ground penetrating radar can usefull y integrate traditional geologic field studies. (C) 2001 Elsevier Science L td All rights reserved.