This study addresses the question of the origin of limestone pavements including what mechanisms cause “grikes” (fractures), “runnels” (anastomosing, shallow cm-scale channels in the limestone), “clints” (limestone bridges within grikes), and popup ridges. Relationships between features and crosscutting in fractures were used to understand the sequence with which these features were created. Ground Penetrating Radar was also used to understand the depth of fracturing and the orientation of limestone bedding at depth. Fracture widths vary along individual fractures with the widest fracture widths being associated with where runnels and other fractures intersect. The cyclicity of these pavements in space seems to suggest that they are not directly caused by glacial movement over the rock, because popup ridges are in some areas but not others. We suggest that local microrelief may be related to the size and extent of Grikes.
|Presenter:||Rebecca AG Rhodes (Undergraduate Student)|
|Time:||1:45 pm (Session III)
Please note that presentation times are approximate. If you are interested in attending sessions with multiple presentations, please be in the room at the start of the session.
American Democracy Project Lecture: Janet Poppendieck
5 pm - 5:45 pm