Curious about something I saw

Hey all,

I was hiking along the Mississippi River in central Minnesota earlier this week and saw this damage. I've never seen anything like it before. There is some beaver activity on the area. The tree appeared to be attached to the bank, but the soil and wood damage made it unclear. I suppose river could have washed it down. Any and all ideas are welcome, it's a complete mystery to me

I have to say I find that quite fascinating and thank you for sharing!
My thought is that the tree has been in the river a while and the damage you see is the internal structure of the tree exposed by erosion, probably in the water. The fins are the fibres within the trunk that would have supported branches (now all missing). Because these are stronger and tougher than the general wood they remain after the rest of the trunk has been eroded away. I could imagine that in times of flood there is a fair amount of sediment in the water that would sand blast anything in there. Even water can cut things at high enough pressure (ever hear of water jet cutting?) and sand would increase that ability many fold. The tree may have been felled initially by beavers, or snapped off for other reasons, or still be attached at the root end - I can't tell which way is up!

Could it be a telephone pole? The treatment may have given it some unusual properties. It's also odd how the growth rings are delaminating. They look so soft, it's no wonder they weathered away more than the heartwood.

I feel Jordan has got it right.

That does look like a telephone pole that has been washed up with a bunch of other trees and debris.

That pole is a different color than the trees and is perfectly round like a telephone pole.

And I also agree it looks like it has been in the water a long time.

Agreeing with the others on the reason for thinking of this as a pine pole, either from telephone/power pole or similar lumber.  Interestingly, the southern yellow pine is considered one of the most common species destined for pole lumber....and when tunneled into by a pine beetle can succumb to fungal infection.  The pattern of the fungal infection (blue staining....see below) is not unlike the pattern remaining from the degraded wood in the OP's photo. Don't know if this would result in the 3D pattern observed or not.  Interesting find!

It looks a bit more washed out on my computer, but on my phone the color of the pole in question is pretty typical of the yellowish, greenish treated poles I see around here. I think the green is from copper compounds. I suspect the odd star shaped heartwood is from where the tree was cut right above the buttress roots. There tends to be a lot more resin down there also, making it more rot resistant, and being the end that was originally set in the ground, the sapwood would have already started to rot more than the rest of the pole, which is why it was likely retired. It's definitely interesting in any case.

Jordan Holland wrote:It looks a bit more washed out on my computer, but on my phone the color of the pole in question is pretty typical of the yellowish, greenish treated poles I see around here. I think the green is from copper compounds. I suspect the odd star shaped heartwood is from where the tree was cut right above the buttress roots. There tends to be a lot more resin down there also, making it more rot resistant, and being the end that was originally set in the ground, the sapwood would have already started to rot more than the rest of the pole, which is why it was likely retired. It's definitely interesting in any case.

I like Jordan's explanation as a likely answer. Another possibility -  a species where medullary rays are significantly harder than the wood, and very prominent.

A water "sanded" telephone pole, where the most dense parts of the trunk haven't been degraded yet from continuous water friction.

To the OP:   Your mission now is to revisit that log twice a year, once in the spring and once in the fall, to examine continued decay.  (In winter it will be under snow, in summer you will be battling the vacationing hordes from the Twin Cities!...)   If the strange pattern is due to vascular rays that mostly tracked on root growth, then their presence should decline as you get farther up the tree....but this can only be examined with continued monitoring as the log  is catabolized over time by microbes and chewed upon by other beasties.  

This should occur over ~12-20 years....... so lock in your travel dates in advance!  :-)

Mission completed. I revisited the location and checked it out. My bet is that Jordan is right and this is a telephone pole. It is detached at both ends and I saw no branches. With how long and straight it is, I'd be surprised if it were any kind tree. Thank you guys for all of your input!