Fossil and rock identification

[Evo]

A number of people have said they are interested in this topic.

Please posts any pictures, information or questions about rocks or fossils here.

I'll start off with some odd formations in rock here from the Pennsylvanian period (318.1 to 299.0 mya).

They appear to be strips of wood, but why do they always appear as strips, no depth? I can't find anything online. I'm dating them by the fossils found in the rock with them.

 

[Evo]

Sorry, I need to upload these to a webhosting site and resize them.

 

[Evo]

Ok, more.

This is a block of wood in stone from the same era as above.

 

[Evo]

Small fossils, including what appears to be a fern leaf I found in an ancient river bed.

 

[DrDu]

Interesting thread!
So that is from the period when the variscean orogenesis took place?

 

[Evo]

Interesting thread!
So that is from the period when the variscean orogenesis took place?

Yes, in Kansas , we had many periods at and below sea level, and we were below the equator at the time.

 

[billiards]

Just a note, I know pretty little about fossils, but I believe it is standard practice to put a "scale bar" into pictures. Rocks can be notoriously 'self-similar', meaning that it can be very difficult at times to know from pictures whether you are looking at an angular pebble, or an angular mountain top! That is, unless of course, there is a sense of scale. A simple coin, or other well known object usually suffices for fossils.

 

[Evo]

Just a note, I know pretty little about fossils, but I believe it is standard practice to put a "scale bar" into pictures. Rocks can be notoriously 'self-similar', meaning that it can be very difficult at times to know from pictures whether you are looking at an angular pebble, or an angular mountain top! That is, unless of course, there is a sense of scale. A simple coin, or other well known object usually suffices for fossils.

HEY! *I* know how big they are!

Good idea. Ok, so I just got back from risking my life hanging off the edge of a cliff while holding a camera just so I could place a nickel next to the odd wood-like strips. Ok, I wasn't hanging, but I did have to lean in an awkward position on the boulder and it IS on the edge of an overhang.

 

[Evo]

These "strips" are everywhere, what are they?

 

[turbo]

Most of the fossils in this area contain simple bivalves from when this place was under sea-water, however I still have my anti-gravity fossil rock from the Alpha Centauri system.

 

[billiards]

HEY! *I* know how big they are!

Good idea. Ok, so I just got back from risking my life hanging off the edge of a cliff while holding a camera just so I could place a nickel next to the odd wood-like strips. Ok, I wasn't hanging, but I did have to lean in an awkward position on the boulder and it IS on the edge of an overhang.

*Much* better.

I still don't know what they are though

 

[Evo]

This one is a real shame, what a nice brachiopod specimen it would have been.

 

[Evo]

Most of the fossils in this area contain simple bivalves from when this place was under sea-water, however I still have my anti-gravity fossil rock from the Alpha Centauri system.

I love your "anti-grav" rock!

 

[austinuni]

A number of people have said they are interested in this topic.

Please posts any pictures, information or questions about rocks or fossils here.

I'll start off with some odd formations in rock here from the Pennsylvanian period (318.1 to 299.0 mya).

They appear to be strips of wood, but why do they always appear as strips, no depth? I can't find anything online. I'm dating them by the fossils found in the rock with them.

Do you think they look like these Calamites?

 

[Evo]

Some rocks.

 

[Evo]

Do you think they look like these Calamites?

That's it! Thank you!

 

[Evo]

This is what I call "swimming yams". Any guesses?

 

[austinuni]

That's it! Thank you!

That's exciting! You gave a lot of good information to help track it down. Any more info on the swimming yams?

 

[Evo]

That's exciting! You gave a lot of good information to help track it down. Any more info on the swimming yams?

Notice the empty indentations? That's where yams fell out.

Normally, the fossils are the usual hard white substance. But I have found a large number of rocks recently where the fossils are of a soft, crumbly orange substance. These are all from this area, both the white and the orange. I'm wondering what the orange yam like fossils could be.

Here's an orange fossil of possibly a crinoid?

 

[Evo]

Can anyone identify this type of rock and what caused the pits?

 

[Andre]

Can anyone identify this type of rock and what caused the pits?

A guess, maybe those are calcite etch pits

Calcite (if it's that) will dissolve slowly in rain water (chemical weathering) which is slightly acid (due to carbonic acid - dissolved carbon dioxide) and little dents may grow out to pits. There is not a lot of literature about it.

http://www.limestone-pavements.org.uk/geology.html
http://www.essc.psu.edu/~brantley/publications/dislocations.pdf[/URL]

 

[DrDu]

Can anyone identify this type of rock and what caused the pits?

A coral may be?

 

[Evo]

Thanks, both of you. I've been reading that similar holes are formed in rocks when iron ore they contained dissolved. Iron might also explain the reddish discoloration on the rock surface. I'm still searching, the rock is heavy, solid, and very hard, so far, I've ruled out calcite.

I have more rocks I need to post so please keep the ideas coming.

 

[dlgoff]

Okay. I finally bought a "point and shoot". Here's my first two photos.

http://imageshack.us/a/img442/3152/arrowheads1.jpg

http://imageshack.us/a/img18/2004/arrowheads2.jpg

All of these where found in Arkansas with the exception of the middle one on the bottom row of the first picture, which was found in Kansas.

 

[Evo]

Very nice dl!

 

[chemisttree]

Can anyone identify this type of rock and what caused the pits?

This looks like a textbook example of 'tafoni' weathering in rocks. This type of weathering pattern occurs in 'case hardened' rock where the hardened outer surface is somewhat more reisitant to weathering than the softer interior. Nice example.

 

[Evo]

This looks like a textbook example of 'tafoni' weathering in rocks. This type of weathering pattern occurs in 'case hardened' rock where the hardened outer surface is somewhat more reisitant to weathering than the softer interior. Nice example.

Oooh. Now I will have to photograph the huge rock slabs that are pockmarked, I'll post some tomorrow, it's getting dark.

 

[chemisttree]

Evo,
You taking a geology course? I sure hope we're not doing your homework for you.

 

[Evo]

Evo,
You taking a geology course? I sure hope we're not doing your homework for you.

LOL! No, I've always had a love of rocks and fossils and now find myself sitting on top of an enormous fossil bed.

 

[Evo]

This gives you an idea of the density of the fossil layers.

 

[Ms Music]

and now find myself sitting on top of an enormous fossil bed.

Lucky!

I have 4 days off work, (Thurs - Sun) so I will either a/ forget this thread completely, or b/ remember and post some pictures. Is it okay to post pictures of collections in this thread even though it is called "fossil and rock IDENTIFICATION"? Or should I use the old thread?

Evo, your swimming yams reminds me of one day at the ocean. There was a walkway cut through a small sand dune, and part of the dune also had collapsed to show the interior. Although it was sand, there were these orange clam looking blobs in the sand same as your picture. I always wondered how you could get orange blobs of sand mixed with normal sand. Probably completely different, but they look the same as your picture, none the less.

 

[Evo]

Lucky!

I have 4 days off work, (Thurs - Sun) so I will either a/ forget this thread completely, or b/ remember and post some pictures. Is it okay to post pictures of collections in this thread even though it is called "fossil and rock IDENTIFICATION"? Or should I use the old thread?

Collections are definitely ok.

Evo, your swimming yams reminds me of one day at the ocean. There was a walkway cut through a small sand dune, and part of the dune also had collapsed to show the interior. Although it was sand, there were these orange clam looking blobs in the sand same as your picture. I always wondered how you could get orange blobs of sand mixed with normal sand. Probably completely different, but they look the same as your picture, none the less.

I wonder what they are?

 

[cousin it]

This looks like a textbook example of 'tafoni' weathering in rocks. This type of weathering pattern occurs in 'case hardened' rock where the hardened outer surface is somewhat more reisitant to weathering than the softer interior. Nice example.

That is not "tafoni" weathering. I agree with the earlier respondent that it is some kind of cnidarian. Take a hammer and give it a good whack... let us see a fresh surface.

 

[cousin it]

A ventral and a dorsal of an asaphid trilobite(Isotelus gigas).
Ordovician of Kentucky
http://www.flickr.com/photos/30726183@N05/5423389797/

 

[Evo]

That is not "tafoni" weathering. I agree with the earlier respondent that it is some kind of cnidarian. Take a hammer and give it a good whack... let us see a fresh surface.

Definitely not a sponge (cnidarian).

http://www.google.com/search?aq=&rl...ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi