Help identifying a rock/fossil + Post your finds

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Help identifying a rock/fossil + Post your finds

#1  Postby The_Piper » Feb 28, 2010 1:03 pm

I found this rock in the brook behind my house. I'm not sure if it's a fossil, an artifact, or a funny coincidence.
Does anyone care to speculate? I also thought it might be a fun idea to look at pictures of other amateur finds. (This is my first new topic so I hope it's in the right place)
http://xs.to/image-8134_4B729C91.jpg
http://xs.to/image-8EB4_4B729C91.jpg

Edit--pictures very big
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Re: Help identifying a rock/fossil + Post your finds

#2  Postby theropod » Feb 28, 2010 2:29 pm

Piper,

Attempting to ID such objects from 2-D images can lead to many errors, but having never been afraid to screw up in the past I will not now break from that pattern. :grin:

I think what you have there is a concretion. These often form when organic matter forms a bacterial mat as the organic material is decomposing. Sediments are trapped in this mat and as other sediments accumulate and the concretion forms. This may well have a fossil inside, or be an actual fossil, but it looks like a concretion.

Can you take a more close-up picture of the strand like structures so that we can see the points between them and the interior of the layer where the filaments are seen?

Also do you know the general age of the rocks in your area where this was found?

Can you please also provide some description of the rock on either side of the layer where the filaments are seen?

This is fun, but again risky. Do you have any geology or paleontology persons locally that might be able to help?

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Re: Help identifying a rock/fossil + Post your finds

#3  Postby Weaver » Feb 28, 2010 2:42 pm

Oh, come on - it's obviously fossilized monorail tracks from advanced theropod civilizations which existed just before the Flud!

Seriously, that's a very interesting specimen!
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Re: Help identifying a rock/fossil + Post your finds

#4  Postby Alnilam » Feb 28, 2010 9:45 pm

Awesome. What a cool looking thingy.

Yes, declaring it a "thingy" is the extent of my knowledge :)

Could be something that was part of a ship many moons ago?

Bril find either way :)
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Re: Help identifying a rock/fossil + Post your finds

#5  Postby The_Piper » Feb 28, 2010 9:59 pm

Thanks guys. Speculate away Theropod, I'm learning new stuff :) As long as you don't mind.
I've been busy trying to find out the age of the rocks around here. I finally found this map http://www.maine.gov/doc/nrimc/mgs/explore/bedrock/facts/geol-hist-1.htm and I'm certain that I lie either in the area of middle Ordovician to middle Devonian, or Cambrian to middle Ordovician. That map has no reference points, and I am near the border of the 2 zones.
Also, this region was affected by glaciers. There is vertical strata along the same brook...by strata I mean the layers of sediment in boulders, etc, that are visible in lines :drunk:
The rock seems like a ball of igneous rock with sedimentary rocks stuck to the outside. I know little more than that for terminology unfortunately. The igneous rock looks and feels like granite, but it "glistens" more, is darker, and looks like it might be more dense. The "teeth" also look like granite, of a lighter, more familiar color than in between the teeth. They also "glisten". It's appears to be 4 different small rocks stuck to the outside. It's a little dirty from brook sediment. I turned it over on it's side and a small piece of the corner flaked off from the darker colored sedimentary rock. It revealed a reddish stain on the interior. I see that a lot with sedimentary rocks found in the area. There is a dark flaky sedimentary rock on both flat sides, and also a gray colored rock on both sides that is more solid. I think it is sedimentary also because I found another rock in the brook with definite fossils in this type of rock. It looks somewhat like compressed beach sand.
I might have some luck finding someone in the area with at least a little working knowledge, but no one I can think of yet. Population here, 247 :lol:
I took many more pictures, but my camera is pretty lousy at close-ups.
Image
Image
Image
Image
Image
Image

Here is the other fossil I found, about 10-15 yards downstream, and 3 years prior.
Top
http://xs.to/image-4721_4B729C91.jpg
Bottom
http://xs.to/image-F459_4B729C91.jpg

Edit: Edited on behalf of the Op - Mazille
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Re: Help identifying a rock/fossil + Post your finds

#6  Postby theropod » Mar 02, 2010 1:13 am

The_Piper wrote:Thanks guys. Speculate away Theropod, I'm learning new stuff :) As long as you don't mind.
I've been busy trying to find out the age of the rocks around here. I finally found this map http://www.maine.gov/doc/nrimc/mgs/explore/bedrock/facts/geol-hist-1.htm and I'm certain that I lie either in the area of middle Ordovician to middle Devonian, or Cambrian to middle Ordovician. That map has no reference points, and I am near the border of the 2 zones.
Also, this region was affected by glaciers. There is vertical strata along the same brook...by strata I mean the layers of sediment in boulders, etc, that are visible in lines :drunk:
The rock seems like a ball of igneous rock with sedimentary rocks stuck to the outside. I know little more than that for terminology unfortunately. The igneous rock looks and feels like granite, but it "glistens" more, is darker, and looks like it might be more dense. The "teeth" also look like granite, of a lighter, more familiar color than in between the teeth. They also "glisten". It's appears to be 4 different small rocks stuck to the outside. It's a little dirty from brook sediment. I turned it over on it's side and a small piece of the corner flaked off from the darker colored sedimentary rock. It revealed a reddish stain on the interior. I see that a lot with sedimentary rocks found in the area. There is a dark flaky sedimentary rock on both flat sides, and also a gray colored rock on both sides that is more solid. I think it is sedimentary also because I found another rock in the brook with definite fossils in this type of rock. It looks somewhat like compressed beach sand.
I might have some luck finding someone in the area with at least a little working knowledge, but no one I can think of yet. Population here, 247 :lol:
I took many more pictures, but my camera is pretty lousy at close-ups.
Image
Image
Image
Image
Image
Image

Here is the other fossil I found, about 10-15 yards downstream, and 3 years prior.
Top
http://xs.to/image-4721_4B729C91.jpg
Bottom
http://xs.to/image-F459_4B729C91.jpg
Edit: Edited on behalf of the Op - Mazille


Piper,

Well, I'm sorry but I don't think these are fossils in the sense that most folks think of them. I think the first object with the "teeth" is where intrusions of some sort have penetrated fissures and resulted in silicate crystals forming in these bands. These fissures may have resulted from exposed mud drying and cracking and then being covered with mud of a different texture and composition. Again, without some crisp close-ups I'm speculating wildly.

Is the layers sandwiching the the "teeth" layer both the same type of rock?

Try this on the non-tooth layers. As a test you could try a 3 part water one part white vinegar etching. If you can form a masking "dike" with warm wax, and then allow to cool, so that only a small portion of the surface can be exposed to the acid you can find out if the stone is of a limestone composition. If the rock is limestone it will react with a fizz. When the fizzing stops clean off the wax damn/dike, wash the area with a baking soda water (1 part soda 5 parts water by volume acid neutralizer), allow to dry, and examine the etched area with as high power magnifier as you can. Report what you see, and the reaction to the acid solution. This weak solution should only clean the area and not erode the rock to any great extent. If the rock is non reactive we need to take another tack.

The second object looks to me like limestone that has been etched by ground water that has absorbed tannin from decomposing hardwood leaves. This is a natural etching process much like the procedure above. This same type of stone can often be found near areas where caves can be found.

Keep me informed and we'll get to the bottom of this.

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Re: Help identifying a rock/fossil + Post your finds

#7  Postby The_Piper » Mar 02, 2010 2:31 am

Hi Therapod, thanks for replying!
No news is bad news, it's still a really cool rock. I'll find more fossils soon.
If this thing wasn't ever alive, it's even more weird to me.
About the 2nd rock, I'm pretty sure those are fossils in it. The camera blends the shadow with the flash, and I couldn't get a good enough pic without the flash. I need a better camera.
There are items lodged in the rock that have a round 3d shape.
When I first found it, I thought it was birdock, the velcro-type plant. After I found the "teeth" rock, I remembered the "birdock" rock and had a closer look and noticed a shell. Now I think that the "birdock" in the rock might be small round bristly sea animals. The shell might be a flattened indented bristly animal(it's shaped like a shell top down), a shell, or it all could be fossilized birdock. Etc :dopey: I edited the pictures and circled the embedded items.
http://xs.to/image-9695_4B8C7278.jpg
http://xs.to/image-46AB_4B8C7278.jpg
Is the layers sandwiching the the "teeth" layer both the same type of rock?

The layer of rock that contains the "teeth" is different from the outside layers. The outside layers would be the "bread" if it were a sandwich. Those are made of 2 different types of rock. Both of those types of rock making up the bread of the sandwich are different from each other, and different from the layer in the middle that contains the teeth.


Try this on the non-tooth layers. As a test you could try a 3 part water one part white vinegar etching. If you can form a masking "dike" with warm wax, and then allow to cool, so that only a small portion of the surface can be exposed to the acid you can find out if the stone is of a limestone composition. If the rock is limestone it will react with a fizz. When the fizzing stops clean off the wax damn/dike, wash the area with a baking soda water (1 part soda 5 parts water by volume acid neutralizer), allow to dry, and examine the etched area with as high power magnifier as you can. Report what you see, and the reaction to the acid solution. This weak solution should only clean the area and not erode the rock to any great extent. If the rock is non reactive we need to take another tack.

I'll need to get those items. This might take a couple of days to get the free time to carry out, if I have company. What's the purpose of finding out if it's Limestone?
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Re: Help identifying a rock/fossil + Post your finds

#8  Postby theropod » Mar 02, 2010 12:15 pm

Piper,

Limestone IS a form of fossil made up of very small skeletal structures of dead critters. Often within the mass of very small creatures that make up the majority of a mass of limestone one can find larger representatives of once living organisms. I have a nice ammonite in just such a setting. Be aware that there are many different types of limestone. Some of it is very hard while other forms are relatively soft. I find the older it is the deeper it has been and more compression has hardened it. Both of the bread "layers" may still be a form of sedimentary rock, as is the "meat". See what I mean about attempting to ID things like this from picts?

I keep an eye on this thread for your reports. There's no rush, at least for me.

I'd contact the Maine geologic survey in the mean time.

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Re: Help identifying a rock/fossil + Post your finds

#9  Postby The_Piper » Mar 02, 2010 3:16 pm

Hi Therapod,
I think the inside "meat" layer that holds the teeth is igneous.
No great rush here either.
I read this interesting tidbit at the Maine geological survey.
"Unfortunately there is a significant gap in Maine's fossil record from approximately 360 million years ago to about 1 million years ago. This gap is most likely the result of episodes of mountain-building and erosion which removed the record of rocks formed during this time period. Most recently, continental glaciers scoured the landscape, removing more sediment and rock. While this erosion was helpful in exposing the older, Paleozoic rocks, it completely removed all of the Mesozoic material and a large portion of the Cenozoic record."
http://www.maine.gov/doc/nrimc/mgs/explore/fossils/fossil.htm
Apparently there are 2 places to view fossils in my region. They are 65-80 miles away. Luckily I visit those towns often so it won't be a big deal to take them along next time I go.
I live 15-20 miles from this spot!http://www.maine.gov/doc/nrimc/mgs/explore/fossils/stfossil.htm
That'll be fun to look at.
Finally, (for the second rock), I found this picture of "Brachiopods" that looks like the one flat shell I described earlier.http://www.maine.gov/doc/nrimc/mgs/explore/fossils/bedrock/brach.htm
The "round bristly animals" in my 2nd rock have actual bristles instead of grooves in a shell. Now I realize from the other picture, that "may" be due to being an imprint. I've learned a bit already :P
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Re: Help identifying a rock/fossil + Post your finds

#10  Postby theropod » Mar 02, 2010 8:17 pm

Piper,

Look HERE for some line drawings of Devonian fossils.

Here's an image of a few Devonian representatives.

Image

You may have a gastropod (snail) or other fossil, but unless this is an unusual brach it shouldn't have spines. However note that image #11 shows one such brach.

Careful, I'll turn you into a paleontologist and we can't have that! :grin:

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Re: Help identifying a rock/fossil + Post your finds

#11  Postby The_Piper » Mar 03, 2010 4:17 pm

Thanks for the link, it's very useful. :cheers:
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Re: Help identifying a rock/fossil + Post your finds

#12  Postby Faithfree » Mar 03, 2010 4:48 pm

The_Piper wrote:Thanks guys. Speculate away Theropod, I'm learning new stuff :) As long as you don't mind.
I've been busy trying to find out the age of the rocks around here. I finally found this map http://www.maine.gov/doc/nrimc/mgs/explore/bedrock/facts/geol-hist-1.htm and I'm certain that I lie either in the area of middle Ordovician to middle Devonian, or Cambrian to middle Ordovician. That map has no reference points, and I am near the border of the 2 zones.
Also, this region was affected by glaciers. There is vertical strata along the same brook...by strata I mean the layers of sediment in boulders, etc, that are visible in lines :drunk:
The rock seems like a ball of igneous rock with sedimentary rocks stuck to the outside. I know little more than that for terminology unfortunately. The igneous rock looks and feels like granite, but it "glistens" more, is darker, and looks like it might be more dense. The "teeth" also look like granite, of a lighter, more familiar color than in between the teeth. They also "glisten". It's appears to be 4 different small rocks stuck to the outside. It's a little dirty from brook sediment. I turned it over on it's side and a small piece of the corner flaked off from the darker colored sedimentary rock. It revealed a reddish stain on the interior. I see that a lot with sedimentary rocks found in the area. There is a dark flaky sedimentary rock on both flat sides, and also a gray colored rock on both sides that is more solid. I think it is sedimentary also because I found another rock in the brook with definite fossils in this type of rock. It looks somewhat like compressed beach sand.
I might have some luck finding someone in the area with at least a little working knowledge, but no one I can think of yet. Population here, 247 :lol:
I took many more pictures, but my camera is pretty lousy at close-ups.
Image
Image
Image
Image
Image
Image
Edit: Edited on behalf of the Op - Mazille


To me it looks likes a brittle layer (in the middle), possibly a vein of calcite, has fractured due to compressive forces and a different mineral that is more resistant to erosion or dissolution has been deposited in the fractures. Differential weathering has produced the tooth-like appearance due to the later formed fracture filling material being more resistant.

The_Piper wrote:
Here is the other fossil I found, about 10-15 yards downstream, and 3 years prior.
Top
http://xs.to/image-4721_4B729C91.jpg
Bottom
http://xs.to/image-F459_4B729C91.jpg


Hard to be sure, but these look more promising as real fossils. Particularly the bottom one; my first thought was horizontal cross-sections through solitary corals, but some don't look right for that.
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Re: Help identifying a rock/fossil + Post your finds

#13  Postby The_Piper » Mar 05, 2010 1:36 pm

To me it looks likes a brittle layer (in the middle), possibly a vein of calcite, has fractured due to compressive forces and a different mineral that is more resistant to erosion or dissolution has been deposited in the fractures. Differential weathering has produced the tooth-like appearance due to the later formed fracture filling material being more resistant.

That sounds like a good explanation. One question I have is, why is there a sharp contrast between the middle layer and the outside? The edges that separate the different types of rock are sharp. They don't appear to have been eroded by water for long.(to me) Could the middle layer with the fractures have formed earlier, and then somehow fused to the sedimentary rocks later?

The second rock, I'm confident that they are fossils. Exactly what kind, I don't know.
They look similar in shape to brachiopods. My current guess now is that they are "reversed image" imprints from the inside of the shell, that got slightly warped.
That might explain why it has bristles.

I'll do my best to have them looked at as soon as possible. I'll also try to get clearer pictures.
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Re: Help identifying a rock/fossil + Post your finds

#14  Postby drl2 » Mar 05, 2010 5:54 pm

The spoils piles from the dredging of the Chesapeake and Delaware Canal are in state parkland near my home, so we make an occasional family trip to sift through the sand and look for objects of interest. The item I'm most anxious to identify is this:

Image

(It's been suggested this might not be a fossil but rather a curious brown calcite formation.)

We find a lot of belemnites there:

Image

Image

A fair number of clam/oysterlike shells, though not often as whole and solid as this one:

Image

The prize of our collection is this fossilized ammonite, which reflects light with a prismatic effect which isn't readily apparent in the photo:

Image
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Re: Help identifying a rock/fossil + Post your finds

#15  Postby theropod » Mar 05, 2010 11:00 pm

Is anyone else thinking the first object might be a burrow infill?

Do you have a good temporal setting for these fossils, or is this coming from several erosional settings?

I know the ammonite can be no younger than the Late Cretaceous. Can I get a top view of that ammonite, please?


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Re: Help identifying a rock/fossil + Post your finds

#16  Postby The_Piper » Mar 05, 2010 11:50 pm

Awesome pics Drl2. What is the last picture of?
I'd say the 1st pic looks like a piece of metal hehe, but I imagine you ruled that out already.
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Re: Help identifying a rock/fossil + Post your finds

#17  Postby drl2 » Mar 06, 2010 1:18 am

theropod wrote:
Do you have a good temporal setting for these fossils, or is this coming from several erosional settings?


Since the spoils piles where they were found have been dredged up from a canal that's been dredged many times before, loaded onto trucks, and dumped there, I suspect there's not much chance of being able to say for certain. The belemnites, which are the most numerous fossils there, are from the late cretaceous

I know the ammonite can be no younger than the Late Cretaceous. Can I get a top view of that ammonite, please?


I'll try to remember to take a few more shots sometime this weekend during daylight.
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Re: Help identifying a rock/fossil + Post your finds

#18  Postby jaydot » Mar 07, 2010 8:30 pm

you lucky blighter, you have all sorts of interesting stuff lying around. the first set of pix, i would suggest have some ferrous content. bits of it look like iron from here, but with only two pix, it's not possible to be certain.

the bottom of the second set looks like an ammonite.
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Re: Help identifying a rock/fossil + Post your finds

#19  Postby The_Piper » Mar 08, 2010 5:43 pm

jaydot wrote:you lucky blighter, you have all sorts of interesting stuff lying around. the first set of pix, i would suggest have some ferrous content. bits of it look like iron from here, but with only two pix, it's not possible to be certain.

I don't think you were referring to my rock, but I'm not sure because you said 2 pix. Drl2's item only has one pic.
Which one did you mean?

I called the university museum curator about my rocks, no calls back yet. :lol:
I'll find someone soon enough, I just have to keep looking.
I spent much of the past weekend reading about fossils, mostly specific to the ones I'll find in my area.
I hope to keep this thread going and get more pictures of other people's finds. I already found some more interesting rocks and another fossil behind my house yesterday. All in 5 minutes of searching. (After I fell through the ice :x )

I found this forum...http://www.thefossilforum.com/index.php? that looks promising to laymen for trying to ID a fossil.
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Re: Help identifying a rock/fossil + Post your finds

#20  Postby jaydot » Mar 08, 2010 7:14 pm

The_Piper, should have made it clear. your op had two pix that looked like they had ferrous content. the second set you posted has what looks like ammonite on its underside (second pic).
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