Tuesday, August 9, 2011

WOGE 305

Since I was able to eventually locate Péter Luffi's interesting "round-ish something" in India, I get to host WOGE once again.  Since the large dimensions of the view Péter gave were very helpful in the search, I will return the favor.  None of my previous three WOGE pictures have included any real rock formations, so this time I will give you a site that is know for interesting and beautiful rock formations.  Since they are a little difficult to pick out, I have included a close-up image.

As you might guess, these rock formations are not know for their size.  However, they are quite interesting because of where they are.  Finding information about this site can be challenging, so here is a hint: once you find the location in Google Earth, pull back and do a Google search for the names of some of the towns nearby.

I will invoke the Schott rule (past winners must wait one hour for each time they have won - correct post time is 20:15 UTC) just because no one has used it in about a month.  To win the challenge you must find the location and give a basic description of what is of geologic interest here. For more complete rules of WOGE go here.


  1. It's the Broxton rocks in Coffee county, Georgia, US, N31°44'; W82°51'. Davis & Rich, 2003, report that "The Broxton Rocks [...] occupies a portion of the Atlantic Coastal Plain where strata of Middle Miocene age dip gently eastward. “The Rocks” are erosional remnants of the Altamaha Formation, and exhibit outcrops that are less than six meters high, and contain numerous sub-vertical and vertical joints. Many of the joints have been widened by erosion and are large enough to walk through. Three fracture sets are dominant: 1) 095°-275°, 2) 015°-195°, and 3) 185°-355° (all +/-5°). The large fractures show the N-S joints are older than the E-W. Preferred orientations and relative ages correlate fracture sets previously studied on the Coastal Plain of Georgia and South Carolina. Rocky Creek, a first-order ephemeral stream, dissects part of the outcrop and flows in a rectilinear pattern from the knickpoint. Orientations of the stream channel mimic those of the fractures, but with a more dominant NW-SE trend (335°-155°)."
    The rocks are of great ecological importance as they host about 500 species of plants. "The preserve’s 1,650 acres is part of the larger 13,466-acre Broxton Rocks Conservation Area, which is protected and managed by the collective efforts of local landowners, Coffee County, the Georgia Department of Natural Resources and other partners." (The Nature Conservatory, 2011).
    Find a nice image here: http://www.naturenerd.com/images/sd_Broxton%20Rocks%20Falls.jpg

    Davis, L.A. & Rich, F.J., 2003. Broxton Rocks - A geological and ecological island in southern Georgia. GSA 2003 Seattle Annual Meeting (November 2–5, 2003).

    The Nature Conservatory, 2011. http://www.nature.org/ourinitiatives/regions/northamerica/unitedstates/georgia/placesweprotect/broxton-rocks.xml, 2011-08-10, 07:40 UTC.

  2. Congratulations to Christoph for quickly finding the Broxton Rocks. It seems that finding this inconspicuous spot was easier than I thought it would be.
    People who live in more rock-infested areas of the world may not be impressed by cliffs six meters high or a three meter waterfall, but these modest outcrops are the largest single exposure of a sandstone unit that underlies more than 38,000 square kilometers of the Coastal Plain. They provide a unique environment that shelters plant species normally found far to the north or south.
    I look forward to seeing what Christoph has in store for WOGE #306.

  3. WoGE #306 is now at http://www.paleoseismicity.org/blog/2011/08/10/where-on-googleearth-woge-306/