Rollin’ Down the River EarthCache

               This is an earthcache. There is no physical log to sign; instead, you need to visit the destination coordinates and answer questions based upon observation.  This EC will introduce you (or further your knowledge – hopefully) of conglomerate rock. Sandstone is abundent, but visible conglomerate rock appears to be much harder to find.  It will also give you a look back into the geological history of Oak Mountain.

Things to Know before you arrive:

1. Oak Mountain State Park charges a $3 daily usage fee. The park opens at 7 AM.
2. The website for the Park is http://www.alapark.com/oakmountain/.
3. In Oak Mountain State Park, there are @50 miles of hiking trails and caches of all types and difficulty levels. Numerous challenge caches which are specifically designed for Oak Mountain can also be a consideration.  Plan ahead!
4. Alabama State Parks and especially Oak Mountain State Park are strong supporters of geocaching.  Respect all rules so other geocachers can enjoy this Park.

Conglomerate Rock EC

               Sedimentary Rock

               Oak Mountain State Park has mostly sedimentary rock as its foundation.  Shale and sandstone are 2 primary but by no means only rocks in these hills.  The large boulders seen in the higher elevations close-by are primarily sandstone or maybe limestone.  Shale is present but easily eroded by weather; therefore, it is not as visible on the surface. An exception is on the Red Trail where Shale We Talk EC is located!  You might find mudstone, chert, and other varieties of sedimentary rock all throughout the park.  Most of these rocks are formed by slow moving or even “quiet” water, but our observations focus on another sedimentary rock formed at least partially by fast moving water.

               A rock of many pebbles

               Conglomerate rock is the result of fast water capable of moving stones/pebbles of varying size.  In the questions below, you are to select a conglomerate rock near the destination coordinates! There are several small size rocks right on or just to the side of the Blue Trail at the destination coordinates.

The conglomerate rock should be obvious - it does not look like the majority of rocks in Oak Mountain Park.This rock will be made up of several things: 1) it will have pebbles or stones – they may be similar in size and color or a mixture of colors and sizes. 2) A much smaller sediment has filled in the gaps and has become the “glue” that binds the rock into one piece. 

To Receive credit for Rollin’ Down the River:

1. Email me your answers by my profile email link – PLEASE: do not log your answers.  I ask you to provide answers in a timely manner after you log. Thanks!
2. Any pictures pertaining to this Earth Cache are greatly appreciated – but never required.  I do ask that your pics not give away any logging requirements.

Questions:

1. There will be several examples of conglomerate rock near the destination coordinates (6 to 7 of varying quality).  Find one – it looks like a rock made of a bunch of smaller rocks – this will be your rock for observation. In the email – answer - yes, got one or similar.
2. In your opinion, are all the “little rocks” within this conglomerate rock the same – color, size, shape? In your own words – describe it!
3. In your opinion, what type of water movement would be needed to move these larger stones within the rock?  A slow movement (like a lagoon) or fast (like a river or maybe waves washing up on a beach).
4. What color is the “glue” or the silt/sand holding all these separate rocks together?
5. Does the conglomerate rock share a similarity to a material used by man to build things?  A little hint – starts with a C. Do you agree – why/why not?

References

http://trekbirmingham.com/articles/the-geology-of-double-oak-mountain/

http://en.wikipedia.org/wiki/Conglomerate_(geology)