Interesting Piece Of Petrified Wood W/ Petrified Charcoal Found In A Very Unlikely Location

[hor2cultcha]

i found this very beautiful piece of petrified wood w/ very clear petrified charcoal in it way out near the point beyond the largest runway in alameda point, alameda, ca. this area was fill brought in to create the us navy base before wwII. i found it about a year ago and believe that it was brought here in fill from another location sometime before wwII. i find the very clear and mineralized black charcoal on the piece to be very fascinating and unusual. anyone else? also does anyone dare venture a guess as to where the fill in which it was deposited came from? lots of nice sandstone pieces which have created beautiful examples of tafoni. i haven't found any other fossils there though.

also, i recently found a sizable crack in the center of the fossil and i'd like to stabilize it before it breaks open. any suggestions to stabilize it?

thanks in advance for any insight you may have about this beautiful and unusual fossil.

to see photos of the petrified wood, go to: http://flic.kr/s/aHsjwSCtmS

pete veilleux

oakland, ca

[tracer]

the piece is interesting, but i'm not sure about the "petrified charcoal" assessment. it appears to have been tumbled or worn somehow in an active environment like water. the black material appears to have been left more in the lower areas that would have resisted erosion. carbonized material tends to be fragile, and would have been the first thing to go normally if the rock were tumbled. one of your pictures shows some of the black material looking like it has little bits of gravel stuck in it. i find myself wondering if the piece of petrified wood ended up covered in asphaltum somehow and that has differentially worn off it, leaving the interesting visual effects you see on the piece.

[ashcraft]

I agree with Mr. Tracer. It appears to be covered in asphalt, particularly the part with litle pebbles stuck to it. Take a rag soaked in gasoline and wipe it down. If any of the black material comes off, it is oil based.

Brent Ashcraft

[bdevey]

Thats a nice piece, I really like the second to last photo. Your find reminds me of a fossil wood, I recently found, that was carbonized in a pyroclastic flow and later mostly mineralized. Heres a link.

In your piece the charcoalized or carbonized areas appear to have some silica inclusions, I've seen that before. But I must also say, in that last photo SOME dark areas do look like asphalt. Can you post some close ups? I'm curious to see, if its just more mineralization? Sorry I can't help on original location

Bob

edit, some super glue in the cracks will help.

Edited November 16, 2011 by bdevey

[hor2cultcha]

it's not asphalt. i thought the same when i first found it, but it's very hard rock and you can see it's in layers where the tree burned millions of years ago. not quite sure how to describe it, but you can see where it's an actual burned layer of the piece of wood. it's all very hard and heavy. i'm pretty certain that it is very well-fossilized charcoal from when it burned. it may even have burned when buried in some hot [but not too hot] volcanic debris. i'll try to take some better photos of it and post them. can anyone tell me how to post directly here in this thread?

[hor2cultcha]

here's some photos of a piece of petrified wood i found in a pre-ww2 landfill on Alameda Island in California. on one end of the rock, there does appear to be a little matrix that does kind of look like asphalt. it might be since i did find it in a landfill. the sparkly black rock is the charcoal - very different than the other matrix. it's hard rock and very heavy - like the rest of the piece. i've never seen fossilized charcoal before, but it sure looks to be that to me. maybe it was fossilized right after being buried by hot volcanic debris [but not too hot]? i'll try and take some better pics now and post them here.

[tracer]

it isn't charcoal, and the fossil wood isn't burned.

[Auspex]

...can anyone tell me how to post directly here in this thread?

Link to a tutorial

[Auspex]

Beautiful piece

I think it is partially "coalified", though, not charred.

[JohnJ]

Hey Pete, I've merged the new topic you created with this topic since they both are about the same subject. It helps maintain continuity in the responses.

Also, I pulled two photos from your link that show the 'end grain' of your piece.

I agree that it is Not charcoal or burned. I'll go further, based on these two photos, and say that I don't think you have a piece of fossil wood at all. I think it is just an interesting rock that looks very similar to fossil wood. There is too much irregularity in the 'end grain' for wood. I have seen weathered chert banded in this manner. It is also not unusual for banded chert to have vugs of crystals eroded from the planes of the banding. Still, it's not a piece of fossil wood, imo.

[tracer]

oops, looked at the bitumen too much and overlooked the crossing "grain" of the differential weathering. i vote an old piece of hot-laid macadam road base.

[Auspex]

Guys, I still see wood.

[tracer]

Guys, I still see wood.

zoom in on it and look all over it at the "grain". you will see places where the grain crosses itself at right angles and in other strange ways. it isn't wood grain.

(note - i reserve the right to refer to the piece as "bison wood" if necessary to extricate myself from this situation)

[tracer]

"coalified" wood (xyloid lignite) mixed in with stone. the last pic is xyloid lignite that resembles non-fossil wood, but trust me, it's structurally different from non-fossil wood.

[Scylla]

The California coast is home to natural oil seeps, like the La Brea tar pits, but under the ocean. Maybe that is what's coating the rock?

[tracer]

The California coast is home to natural oil seeps, like the La Brea tar pits, but under the ocean. Maybe that is what's coating the rock?

well, yeah, that would work, but then you got to get the little bits of gravel on it and get it to the fill site where it was found, and i don't think they'd be getting fill material from a tar seep.

[xonenine]

very nice unusual banding, a beautiful piece to cut no doubt - I can see why anyone would think it was wood from the sides, several views had me sure of it, but the end pattern seems to settle it as agate.

[Scylla]

well, yeah, that would work, but then you got to get the little bits of gravel on it and get it to the fill site where it was found, and i don't think they'd be getting fill material from a tar seep.

I thought it was found near the beach, ie shipped to the area clean, fell in the water and then got coated in tar, the beach supplies the sand and pebbles?

[tracer]

um...ok!

[hor2cultcha]

okay. there are some tar patches on it which i hadn't noticed in the beginning and i'm trying to get them off. i used alcohol and now i'm using gasoline, but is there something else i can use which will not stain the rock itself? i don't want to be stubborn, but there's no doubt in my mind that it's petrified wood underneath. the lines are concentric throughout the entire piece, but not visible in some spots due to the tar. the shiny, sparkly black is not the tar. it is rock or coal and it's not affected by the gasoline or alcohol at all. i can even see the wood grain in it in most places. maybe that's not visible in my photos. i'll try to get some better photos in daylight using my tripod. thank everyone for your feedback. i'll post some photos of another interesting [definite] fossil i found now.

[hor2cultcha]

i meant to say that the lines are contiguous, but they are also diminishing concentric circles [as in the core of a tree] in places.

[xonenine]

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[tracer]

ok, let's switch the paradigm a bit, because you've been looking at wood all your life, and not banded chert. look at some of the banded chert images here and then tell me why the specimen can't be banded chert. as far as why some of the black isn't particularly soluble, you may have noted in dealing with other material in the past that polymers that are older and oxidized resist solvents much better than fresh stuff. i see a couple of spots where the black flaked off at the edge as a concoidal fracture. the stuff has gotten very stable over the years, and i'm not surprised if it isn't breaking down particularly rapidly with solvent. but "petrified charcoal" isn't going to flake off like that and leave a perfect surface under it. the piece just isn't charred wood.

[tracer]

p.s. - another paradigm test - i found this the other day, in a location where it is not unusual to find fossil wood. what is this?

[squali]

I agree that it is Not charcoal or burned. I'll go further, based on these two photos, and say that I don't think you have a piece of fossil wood at all. I think it is just an interesting rock that looks very similar to fossil wood. There is too much irregularity in the 'end grain' for wood. I have seen weathered chert banded in this manner. It is also not unusual for banded chert to have vugs of crystals eroded from the planes of the banding. Still, it's not a piece of fossil wood, imo.

I have to agree it is not petrified wood but a cool mineral conglomeration . If you look at the piece as a whole, the lines may be uniform but the implied rings are unnatural. Military bases historically consumed building resources close by and then expanded radially from the base. They also kept extensive records. If perhaps you knew that this location was one of the first built you could possibly assume that the construction soils were from on site. otherwise If it is from a construction project to a landfill, the borrow area could be over a hundred miles away.