The Booth Ford Shoal Earthcache
Located at “The Slab” as locals call this place. The Original name of this natural river crossing was Booth Ford. When I came here in 1977, I saw coal trucks crossing the river on the concrete river ford as the strip mines were active here in the area. I talked to a man who was fishing here in 1977 and he told that it was not a big deal to drive across the river here before The Slab came to be. He said, “just follow the shoal along the fall-line”. This Earthcache is about this natural river shoal here at Booth Ford.
If you enjoy doing this Earthcache, please consider giving it a favorite point.
This is an Earthcache, which is a kind of virtual cache where there is no physical log for you to sign, but instead, there are some questions that you must answer while here and then you must send me the answers to those questions either by email (which I prefer) or by message using the smart phone geocaching app. I strongly suggest that you send me your answers BEFORE LOGGING a find. I hate to say this, but if you do not send me your answers within 5 days of your logging this cache find, I will have to delete your find / log.
You will need some kind of navigation compass to complete this Earthcache That compass can be your old handheld Boy Scout Compass or a compass app on your smart phone. I use a compass app called COMPASS X on my IPhone. It is free. The compass on this app looks like a sailors compass. I am an old sailor so this app is like me. You do not have to have cell service to use this app. . I expect your answers to be within a few degrees of perfect.
If the Cahaba River is running at high water and is deeper than 3 feet flowing over The Slab, you can not do this cache as the Shoal here will not be visible.
I suggest that you read the cache description before completing the questions
Questions:
- Is water flowing over The Slab today? If it is, how deep is it?
- What is the compass heading of The Slab looking along the slab edge?
- What is the heading of the Shoal Line (waterfall line) just below The Slab. (not the same as The Slab)
- Why do you think that the engineers who designed the Slab did not follow the waterfall line or shoal direction across the river?
- Examine the sandstone that makes up Booth Ford as water flows over it. Explain why this is a good natural river ford.
- Take a picture of Booth Ford – not optional. Optional: Include yourself in the picture.
Description:
A Shoal is an accumulation of sediment or shallowing of a river channel. In a slow flowing river, the river will slowly drop its sediment load and a shallow shoal can form. Booth Ford Shoals is not that type of shoal. The shallowing of the river to form Booths Ford Shoal is caused by the remainder of a worn-down mountain ridge crossing the Cahaba River here at Booth Ford. A River or Stream Ford is any place in a river that is shallow enough to make a crossing of a river or stream possible.
About 480 million years ago the Appalachian Mountains were formed. At one time, the Appalachian Mountains were as high as the Rocky Mountains are today, about 14,000 to 15,000 feet above sea-level. Those mountains have changed a lot since experienced considerable erosion and other changes due to plate tectonics since their formation. The southern terminus of Appalachian Mountains today is only about 5 miles south of here as the crow flies. The remains of Appalachian Mountain ridgelines that cross the Cahaba River can still be seen today as shallow water sandstone shoals and small water falls like you see here. The sandstone formation here is also unusually flat with consistent depth that makes Booth Ford an excellent natural river crossing.
You might ask why the mining engineers did not build the Slab directly along the exact line of the shoal and waterfall line here at Booth Ford. I asked the same question and this caused me to examine the south exit that would have had to be taken by the trucks coming off the Slab and back into the roads. Look at the steepness of the river backs where the waterfall line meets the south shoreline. Now look at the shoreline and the riverbank where the Slab meets the south shoreline. The riverbank has a much gentler slope here which would make for an easier exit for the trucks crossing the river. The Booth Ford shoal is nice and wide here, so it was not a problem to build the Slab to transect the natural ridgeline of rocks somewhat and not follow the ridgeline exactly. That is why the waterfall line direction and the direction of the Slab are somewhat different. Good common sense engineering and nice wide shoal.
It is these nice wide shallow water ridgeline shoals in the Cahaba River that make the Cahaba River so favorable for the growth the famous Cahaba Lilies in late April and through mid-June.
Documentation:
Wikipedia.org > Appalachian Mountains
Britanica.org > science > shoals
Dr. Richard Carroll – Geologist - University of Alabama