Here's my first attempt at creating a 3D outcrop. Changing spatial perspective is very important in structural geology, and models like this can open up new ways of visualizing and analyzing geology. In this case, I'd like to document fracture sizes and scaling in 3D (more on that below)
Geologic Background

The Devonian Helderberg Group is exposed along large roadcut on Highway 48. These predominantly limestones were deposited in an epeiric sea that existed between the Taconic highlands to the southeast and the Cincinatti and Algonquin arches to the west (Smosna, 1988). The unit has been evaluated as a possible seal for CO2 sequestration purposes associated with the Burger electric power plant (Lewis, et al. 2009).
My interests in digitizing the outcrop are mainly in testing the photogrammetry technique for the purposes of documenting fracture network geometries in 3D. This outcrop is actually fascinating to view from different angles, because several different fracture sets come into view depending on how we rotate the model.
- Rotate the view looking from left to right and you can see the white faces of calcite filled fractures
- Once your eye is trained on the calcite filled fractures, rotate the model the other way and the spacing between those fractures becomes much more obvious.
- As you look closer, you might also notice at least 1 other fracture set whose faces are stained reddish brown.
The 3D Outcrop
(The surface may appear black for a second while the image loads. Best viewed with Chrome, FireFox, or Opera. I'm not sure how well Internet Explorer works.)
Try full screen mode to really be able to zoom around.
I can't wait to dive into this a bit further, especially using these 3D models to help with digitizing fracture data while on the outcrop. There's also great potential for generating orthorectified images of the cliffs in various orientations that are conducive to fracture measurement.
I'll post another outcrop when I get a sec.
I'll post another outcrop when I get a sec.
Location on Google Earth
References
Lewis, J.E., McDowell, R.R., Avary, K.L., Carter, K.M., 2009. Characterization of the Helderberg Group as a geologic seal for CO2 sequestration. Environmental Geosciences 16, 201–210.
R. Smosna, Paleogeographic reconstruction of the Lower Devonian Helderberg Group in the Appalachian basin in N. J. McMillan, A. F. Embry and D. J. Glass (eds.), Devonian of the world: Canadian Soc. Petrol. Geol., v. 1, p. 265-275, 1988.
R. Smosna, Paleogeographic reconstruction of the Lower Devonian Helderberg Group in the Appalachian basin in N. J. McMillan, A. F. Embry and D. J. Glass (eds.), Devonian of the world: Canadian Soc. Petrol. Geol., v. 1, p. 265-275, 1988.