Your camp is all set. You pop a cold one and lean back in the lawn chair by the fire. Next thing you know you are swimming in 10 ft. of water! WTF!!!

Treasure Island on Texoma.

[img]http://i787.photobucket.c[IMG]http://i787.photobucket.com/albums/yy160/SBridgess/Sinkhole014.jpg[/img]

thats what happens when its dry and too many flush at the same time!!

Another one formed on Hog Island in the last 24 hrs. I was kidding about the camping. But now I'm not so sure. I noticed a big crack forming in the sand on one side of the new one. I would like to watch one go! Wonder if they form a small Tsunami?

Wild. Did the shoreline go straight across where your boat is parked in those pictures? What is causing that?

sinkholes?

Technically they would be classified as a slump or underwater landslide. Yes, the original shoreline went straight across.I estimated that distance at about 40 yds. The cut went about 30 yds. into the island. I was reading 8ft. just before my bow touched the shore. There is a steep drop off into the river channel along this part of the islands. Under the sand is a layer of clay. As the lake drops the clay layer can no longer support the weight of the sand and it slides off into the river channel. Trapped Methane gas may also be playing a role.

I thought that current or movement of some type had to be involved, but couldn't fathom (pun partially intended) that the river had any current, at least currently.

A major outgassing event involving methane could prove to be exciting 'round the old campfire.

How 'bout some more beans, Mr. Taggart?
[fans his hat in the air] I'd say you've had enough!

This structure is called a normal listric fault. You can see them alot in the subsurface in the Gulf of Mexico. They move on shale layers called the decoulmont (I might have mispelled the word, it is French). Methane might have been involved, but in small amounts. By the way, mapping these structures is how geologist find oil and gas in the Gulf.

Interesting stuff.

So does being out of the water allow the fault to slide down on that side because it's unsupported?

The fault's movement has to do with the water content of the shale and the weight of the overburden. They can happen underwater or in the subsurface. I think this one would have happened with or without the drought. The sand will get too heavy and the shale will have the right water content, and the growth fault slips. The thing that caught my eye was the comment about the depth finder showing 8 ft until the bow hit. That reminds me of the faults that I see in seismic data. The ones that I see on the creeks here in North Texas are much shallower. I wonder how much water current plays a role in those.

I was going to stay out of this discussion until I just received an email from one of my �trouble maker� fishing buddies �. �As our resident geologist and Texoma expert�what is your take on this?�
The Red River arm of Lake Texoma is a �braided stream� and over geologic time has meandered all over the Red River valley, depositing sand, shale, gravel and conglomerates. Treasure Island is only one of � the islands� that has undergone constant change due to floods as well as low water conditions, re-depositing and sorting the various river sediments.

For the record I am a geologist by education and a geophysicist by profession.
In my �other life� I practiced my profession extensively in the �Gulf��. to correct Mr. Allyn, it�s the Exploration Geophysicists that �find� the oil and gas in the Gulf �

Lake Texoma was a braided stream until the dam was built. Then it became a lacustrine environment. My understanding is that this can change the "energy of deposition" for lack of a better term. Lakes become silt collectors because the flow of water is arrested. I did alot of fluvial work when I was getting my geology degree. Some of that was in the Red River Valley. Some of those bars have great cross bed sets. The pictures reminded me of when I worked the Wilcox in the South Louisiana, but I am starting a Carbonate project in East Texas Salt Basin. I am geologist by education and profession.
Geophysicists come in two camps to me - the guys who find oil and gas and the others who play with squiggly lines and computers. You sound like the first kind. I like those guys! Cheers!

My staff geologists were not allowed to use big words ....

Sorry, I do it to keep the engineers guessing....

ROFL!