North Sulfur River Upper Level Geology?

[wfrr]

For those of you who frequent the North Sulphur River in Fannin County Tx. We were at the south side of the channel at the tributary often referred to as Davis creek. The cliffs are very high there and large columns of dirt are falling off due to erosion. I was examining some of this fall off and noticed a great deal of fresh water muscle shells at a certain level. Looking at the cliff I saw a level perhaps a foot thick at least 12 to 15 ft below ground level and perhaps 12 ft or more from the channel floor. It was loaded with fresh water muscles and chunks of wood. I climbed up some of the debris piles to inspect it at close range and pulled this very fragile bone fragment out of that layer of the bank. There are very few signs of any mineralization.

Given the depth that this bone was situated I conclude that it must be of some great age, perhaps thousands of years old. If that were the case then I would suggest that there must be other bones that erode from the upper layers that are not mineralized to much extent. I've perhaps found and left those on the bed of the river thinking they were cow bones.

After noticing this shell layer I saw that it was still present a couple of miles west of Davis creek. It was marked by large logs protruding from the cliff and a noticeable band of shell material.

I'm sure some of you have seen it too. I figure that it must have been from a very wet period, considering all of the wood perhaps it was after a flood. It must be a boundry line of somekind. Given the organic material found there it would be easy to date if anyone in the scientific community were interested. I've been in the channel many times and never looked very high up the bank before. Perhaps the abundant fossil bones and shells at the lower levels cause many of us ignore the other 40 to 50 ft of sediments.

I've looked at pictures and think it might be a humerus, but its hard to find anything that looks just like it. It would be funny if it were a cow bone..right?

Edited September 24, 2012 by wfrr

[bear-dog]

A good way to help you check if it is a fossil,is to light a match to a small end of it.If it smells like burnt hair it is too young.

[Fruitbat]

I have seen the same upper level shell layers that you describe. The shells are likely Amblema plicata or Lampsilis radiata, two fairly common freshwater mussels that have been found in Pleistocene and Recent layers. A friend of mine and I excavated a virtually complete and somewhat articulated Bison skeleton (lacking only the skull) resting directly atop such a layer in the bank of the North Sulphur River at the Paris bridge. The skull later turned up in the collection of another person who had found it on the riverbed immediately below where we excavated the skeleton. Based on skeletal and skull biometrics I was able to determine that the animal was an exceptionally large, robust specimen of Bison bison and not one of the extinct species. Remember that the current bed of the North Sulphur river is not in its natural state...the river was dredged to its current level by the Corps of Engineers quite some time ago to enhance flood control. It is entirely concievable that the high shell layers and intermingled logs are the result of the aftermath of late Pleistocene to Holocene flooding. Once the floods began to subside the water level would have been high and likely receded slowly, presenting the freshwater mussels with an ideal place to carry out their filter-feeding activities.

One of the former curators at the Dallas Museum of Natural History presented the possibility that, since Amblema plicata and Lampsilis radiata were favorites of the Native American inhabitants of the area that the shell layer might represent an occupation site but I think this scenario is less likely that the flooding scenario, especially since the shell layers are present in multiple locales and can be quite extensive (the Native Americans would have had to eat a LOT of shellfish to produce deposits of that extent).

-Joe

[BobWill]

A good way to tell Bos from Bison is Charles Finsleys "A Simple Comparison of Cow and Buffalo Bones"

It's only 32 pages so easy to use and has excellent photos. It's strictly post-cranial for when there's no skull.

[wfrr]

The possibility of a discernable flood zone level is very interesting to me. I will no doubt pay very close attention to that level in the future. It almost beckons a person to do so with all of the timber protruding from the bank...right? Who knows what could be in there.

I appreciate all replys but even more appreciated are the ones where I am learning something. That is the real reason I am here...to learn. I'll tryb to locate a copy that book too I need it. I don't want to confuse bossy with a bison or worse leave bison remains to wash down the channel. I know I've definately done that at another site.

Edited September 27, 2012 by wfrr

[wfrr]

I have not seen a picture of any humerus yet that is exact but nothing comes as close as a bear. Some of the big cat humerus bones also resemble the one I found.

[wfrr]

I decided to reup this post. I saw a post where a few people discussed the area at davis creek with the log protruding from the bank that someone took a saw to. So people are familiar with what I am looking at. When one considers the depth that log is buried at you would think it's been there a very long time. The same for all of the crumbling bones I keep finding at that level. I found another a couple of weeks ago. I wonder if we aren't looking at the original channel thats been filled in either by nature or by the crew that dredged the straightened channel. What ever happened it's interesting to see those logs hanging out of the bank. Anyone else with thoughts on this subject? Oh these days I don't consider that humerus to be ancient, but I still think it's a lot older than any of us. Just how did it get in that level of the bank?

[BobWill]

I always wondered what kind of tree that log was. Some trees would have rotted in the time I've known about it. Seems too straight and limbless for a bois d'arc , but it has lasted a long time. The river has cut the bed so deep since channelization I suppose the original bed could have been that high so maybe that material was laid down just a few decades ago. On google earth you can still see places where the original channel snakes around. Maybe you could look for one in that area to see it's elevation for comparison.

[wfrr]

There are more like the one at Davis creek farther west esp on the north side. I didn't look to ck if its bois d'arc or not. At the same time I likely would have known by seeing it up close if it were or not. For some reason I find this puzzle interesting.

[Foshunter]

Is this the old tree you are refering to?-----Tom

[BobWill]

Is this the old tree you are refering to?-----Tom

It sure looks like the one I'm thinking of. You can even see some red zone material under it that wraps around the wall there. Is this looking roughly southeast?

[wfrr]

Thats it. I pulled that bone out of the bank in the shell layer. It was about 15 ft or so downstream. There are more trees protruding out of the bank, most notably at about a mile and a half west on the north side. The shell layer is also present at that location as well.