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Getting To Know My Strata....


lissa318

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So despite the good weather I sadly didn't have time to fossil hunt this weekend... Pulled over into a construction site I recently visited and grabbed 3 large rocks. My daughter was in the car so parked next to a pile of rubble. This is the first one I tossed in the back, same rock I found my last calamites impressions in. :). Decided going to practice splitting on this one...

post-8801-0-01750800-1365979536_thumb.jpg

Then saw what I think is a coal layer? Grabbed 2 pieces and the first started crumbling as soon as picked it up.

post-8801-0-93897300-1365980153_thumb.jpg

The destinct layers split like this...

post-8801-0-43233800-1365980395_thumb.jpg

Edited by lissa318
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Can anyone tell me if this is the upper carboniferous layer? The layers I showed will easily crumble like this...

post-8801-0-70360900-1365980838_thumb.jpg

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Hey Lissa,

Your first piece looks like a sandstone.

The "coal" layer is actually shale or mudstone.

It could be Carboniferous.

Hard for me to tell without knowing the local area.

Regards,

    Tim    -  VETERAN SHALE SPLITTER

   MOTM.png.61350469b02f439fd4d5d77c2c69da85.png      PaleoPartner.png.30c01982e09b0cc0b7d9d6a7a21f56c6.png.a600039856933851eeea617ca3f2d15f.png     Postmaster1.jpg.900efa599049929531fa81981f028e24.jpg    VFOTM.png.f1b09c78bf88298b009b0da14ef44cf0.png  VFOTM  --- APRIL - 2015  

__________________________________________________
"In every walk with nature one receives far more than he seeks."

John Muir ~ ~ ~ ~   ><))))( *>  About Me      

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I found this piece that is same but maybe not so crumbly??? Coal, carboniferous, help me out?

post-8801-0-68847400-1365981070_thumb.jpg

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Hey Lissa,

Your first piece looks like a sandstone.

The "coal" layer is actually shale or mudstone.

It could be Carboniferous.

Hard for me to tell without knowing the local area.

Regards,

Thanks Tim I have seen some of the upper carboniferous material that CK has posted and wondering if same material? I can take a pic of the embankment to post later. This is dunkard group in Washington, PA.
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It looks like fissile shale. Split through it and see if something comes up.

Context is critical.

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Just looking at what type of rock you have doesn't tell the age. If you know the formations that show up locally, it can help. Where you can't tell the formations from a geological map you'll need to look for index fossils which are species that lived for a relatively short time, and often micro fossils. Do you use a geological map for your area?

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I mentioned above that it is the dunkard group in Washington, PA. Listed as Permian but certain areas are a mix of Permian and Pennsylvanian from what I understand... An area not far from here has been noted as having shell, fish teeth and scales, plus amphibian tracks. Not to mention carboniferous plant fossils which I love! :) This is what I know based on my research. This fissile shale intrigues me and trying to figure out what is most likely to be found in this type of shale? When I have looked up fish and shark that have been found in this group our CK Merlin pops up a lot. :) This is why I thought possibly same material. Gonna split them Missourian and Rockin Ric, and even if nothing, I may go back for more. Your comments sound encouraging!!! The worst that can happen is finding nothing-right?! ;) Wish me luck. lol :)

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The worst that can happen is finding nothing-right?! ;) Wish me luck. lol :)

And, you get to practice splitting rock, a very empowering experience!

Getting your strata down to group may be enough in some places to identify the layer. I don't know much about geology but I believe Groups are made up of Formations which can be further divided into Members. I use a Texas geo map here that has color-coded formations and comes with a booklet with descriptions of the rock types in each. Even with all this information I still have trouble knowing where to look and where to keep driving :P

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.... I may go back for more.

Ha, I forgot to mention that part. :)

Good luck.

Context is critical.

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Thanks Missourian! :) If you were to find, ummm, nothing (haven't split yet btw so not sure), would you grab more of this shale to split or the sandstone? Or both? Tough for me having a 3 year old... Rather impatient since finally have decent weather!!! :D

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If nothing shows up, it may still be worth going back and splitting through more in case fossils are present (but too rare to show up in your sample). If fossil do show up, then.... :)

As for rock types, sandstone is less likely to preserve fossils due to its grain size.

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Context is critical.

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Very good to know! Thanks! And just found some wee little tiny things... Dunno. Something or just natural occurance? Geesh. No clue?post-8801-0-33351500-1365999336_thumb.jpg

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Whoa.... Looks like ostracods, or possibly fish scales. Can you get in closer?

Context is critical.

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Whoa.... Looks like ostracods, or possibly fish scales. Can you get in closer?

It's hard to get much closer... Pretty small. Here's some pics and I can try again tomorrow. These are cropped and sharpened... Thanks! :)post-8801-0-64940200-1366001887_thumb.jpgpost-8801-0-14572400-1366001911_thumb.jpg

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Here are some ostracods for reference:

post-6808-0-91680700-1364798993_thumb.jpg
post-6808-0-15571300-1364798999_thumb.jpg

All are just less than a millimeter in length.

Edited by Missourian
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Context is critical.

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Some of them look similar to that. There are upraised spots towards the top that i cut out of this pic that are shaped like that too... Plus have a whole other piece now. The area more to the right of this one looks different... A lot of them look flat and appear to have a line through the middle?

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And some living ostracods, just because I love this photo and will use any excuse to repost it. :) :

post-6808-0-64402200-1365909566_thumb.jpg
Notice how ostracods have a distinctive 'lopsided oval' shape. I think I may be seeing that in the fossils in your slab.
Edited by Missourian

Context is critical.

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Those pics are great Missourian!!!! Thanks for sharing them with me!!! :) Fabulous detail considering how small they are. I may need to invest in a microscope?! lol How big can ostracods get? And do you have any thoughts on what the other things might be? After looking more closely today the other spots don't all have just one line, and really not sure if line is the right word to use... Almost looks like an area of separation. Could track marks be a possibility? Can try to get a better pic of those today. Thanks for your help! :)

And some living ostracods, just because I love this photo and will use any excuse to repost it. :) :

Notice how ostracods have a distinctive 'lopsided oval' shape. I think I may be seeing that in the fossils in your slab.

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Way to go Lissa!

Looks like Ostracods to me!

This Website mentions ostracods in the Washington Formation.

Congratulations, Lissa!

Regards,

PS - scroll down this page for more on Ostracods in the area. ;)

Edited by Fossildude19
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    Tim    -  VETERAN SHALE SPLITTER

   MOTM.png.61350469b02f439fd4d5d77c2c69da85.png      PaleoPartner.png.30c01982e09b0cc0b7d9d6a7a21f56c6.png.a600039856933851eeea617ca3f2d15f.png     Postmaster1.jpg.900efa599049929531fa81981f028e24.jpg    VFOTM.png.f1b09c78bf88298b009b0da14ef44cf0.png  VFOTM  --- APRIL - 2015  

__________________________________________________
"In every walk with nature one receives far more than he seeks."

John Muir ~ ~ ~ ~   ><))))( *>  About Me      

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The worst that can happen is finding nothing-right?! ;) Wish me luck. lol :)

And, you get to practice splitting rock, a very empowering experience!

Getting your strata down to group may be enough in some places to identify the layer. I don't know much about geology but I believe Groups are made up of Formations which can be further divided into Members. I use a Texas geo map here that has color-coded formations and comes with a booklet with descriptions of the rock types in each. Even with all this information I still have trouble knowing where to look and where to keep driving :P

And thanks Bobwill!!!! Didn't mean to ignore your comments yesterday. Was wrapped up in trying to figure out what these little things are! :) I have looked at a couple maps, and need to find a really good one to reference. I know there are areas that somewhat overlap here as Allegheny county is Pennsylvanian and Washington is Permian. The dunkard group I have read has fossils in my area that are not present in the West Virginia dunkard group. I believe early Permian meets Pennsylvanian here? I am also not fluent with geography and learning slowly. Missourian provided a link a little while ago that had the best explaination of my area I have read yet. I need to pull it up again. Not sure if there was a map or a link to one that I can print out or not... The minds the first to go right?! lol. ;)
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Way to go Lissa!

Looks like Ostracods to me!

This Website mentions ostracods in the Washington Formation.

Congratulations, Lissa!

Regards,

PS - scroll down this page for more on Ostracods in the area. ;)

Thanks Tim! :) I'm pretty excited!!! And BTW, that first link you posted with the fossil site on it is 5 minutes from me, provided I don't have to stop at a red light... lol! :P Haven't made it there yet since weather just got nice but on my "to do" list. :)
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How big can ostracods get? And do you have any thoughts on what the other things might be? After looking more closely today the other spots don't all have just one line, and really not sure if line is the right word to use... Almost looks like an area of separation. Could track marks be a possibility?

They can get up to a few centimeters, but the Penn-Perm forms only get to a few millimeters. The largest I've seen are these Hollinella:

post-6808-0-12789400-1365841606_thumb.jpg

And regarding the other thing you mentioned, do you mean the dark streak near the bottom? If so, it's hard to say. It could be something, or it could just be how the shale broke.

Edited by Missourian

Context is critical.

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Hi Lissa excellent !! keep splitting that shale I sometimes have to split quiet a lot before I find anything

I always take a strong loop ( a magnifying glass) and field microscope with me to see close up small stuff that I can get under the USB microscope at home later, very often fish scales are tiny about the same size as your Ostracods , Id love to get those little beauties under my USB scope for a close look B) . Ill wager youll find more in that shale

And thanks for the mention cant wait to see more of your finds

found this link hope it helps

http://www.academia.edu/1312343/Callipterids_of_the_Dunkard_Group_of_the_Appalachian_Basin_Their_identity_and_paleoenvironmental_significance

Edited by ckmerlin
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"A man who stares at a rock must have a lot on his mind... or nothing at all'

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