The sandstone hills of Kisatchie Wilderness are drained by this bayou, and in some places the rock bottom is visible, as are the sandy berms and bars built up by the erosion of the sandstone. Learn a little here about the natural rocks in this part of Louisiana and observe this bayou's waterfalls to answer questions based on what you see in order to log this earthcache!
The naturally occurring rock at this location are part of a feature named the Catahoula Formation [1], which is made primarily of sandstone, loose quartz sand, and volcanic ash. It dates to the Oligocene epoch, roughly 34-23 million years. Sandstone in this location can vary in composition: it can be made of fine grains or coarse conglomerates, even containing some clay deposits.[2] Typically sandstone is light brown/tan due to being composed mainly of light-colored quartz crystals. However, it can have altogether different colors based on the presence of other minerals within. Other colors can be Reddish-Orange, due to high percentages of Feldspar, or iron oxides (rust); or Purples due to Manganese; or perhaps even grey or grey-blue due to a significant amount of clay or silt.[3]
At the earthcache location you will see Kisatchie Bayou has eroded the sandstone formation and created a particular feature, rare in this state.
There are several types of waterfalls. Most notably are these common types:
- Cascade: The water descends down a series of rock steps
- Cataract: A large, powerful, plunging waterfall
- Classical Ledge: In which the height of the fall is nearly the width of the stream
- Ribbon: Water descends down a long narrow strip
- Segmented: Distinct flows of water form over the extent of the falls
To log this earthcache, send the cache owner the answers to the following:
1. Observe the sandstone rocks which are visible. Do they appear to be composed of fine-grained sands or coarser pebbles?
2. Which colors do you observe in the sandstone here? What causes the colors you see?
3. How do you think volcanic ash came to exist as a constituent part of the rocks of the Catahoula Formation?
4. Thinking caps: why are the sandbars built of white/semi-white sand, but the rock bed made from a darker-looking stone?
5. At the published coordinates you will hear and see Kisatchie Falls on the south side of the road. Using the description above, which type of waterfall is it?
6. Measure or estimate the depth of the plunge to the water below it.
Utilize Leave No Trace ethics here -- Take only photographs; Leave only footprints.
Photographs are encouraged; but are not required.
Citation 1: https://mrdata.usgs.gov/geology/state/sgmc-unit.php?unit=LAOGc%3B0
Citation 2: Matson, George. (1916). The Catahoula Sandstone. Shorter Contributions to General Geology, Chapter M, 209.-225.
Citation 3: https://www.mineralseducationcoalition.org/minerals/sandstone