Geosphere; February 2008; v. 4; no. 1;
p. 247-259; DOI: 10.1130/GES00139.1
© Geological Society of America
Click on image to view larger version.

Figure 9. Orientation of the fracture planes in thick sandstone beds in area 4, Big Rock Quarry. Area 4 is 100 m distant from area 1 (Fig. 6), and sandstones reach a thickness of
1 m. (A) Picture of the outcrop displaying thick, continuous sandstone beds. (B) Virtual model of the outcrop in A with the point cloud mapping the NW-oriented fracture planes shown in green. (C) Surface classification analysis identifies three orientations for the fracture planes: NW (green), NNW (yellow), and NE (red). Fracture orientations are consistent with those found at the other locations. The magenta points are debris slopes accumulated on ledges. (D) Equal-area stereographic projection of poles to fracture planes (the colors correspond to the identified orientations). Mean vectors are plotted on the stereonet as circles.
Copyright © 2008 by Geological Society of America