Show us your stromatolites

[Tidgy's Dad]

12 hours ago, Wrangellian said:

That's an alga? Wow, it looks like a coral!

There's no reason we can't continue with the Algae thread as well, and leave this one for stomatolites, microbialites and such. It seems there are lots of different kinds of algae/seaweed fossils out there. I'd like to have more myself but when they come up (not often), they get away from me (and I don't think I can find any in my local collecting sites).

Tis a coral. 

It's all a bit confusing. There is a genus of green algae called Cladophora, that exists today and is found in Lake Michigan (and elsewhere)

Then there is the pachyporid tabulate coral of almost the same name, Cladopora, found as fossils in the Lake Michigan area. (and elsewhere)

People get them muddled up.

I'm pretty sure this specimen is the latter. 

Edited May 17, 2021 by Tidgy's Dad

[Wrangellian]

Ah... I would probably make the same mistake, unless I happened to see both.

[Yoda]

After seeing the debate in the other Stromatolite thread re Malachite being biogenic in origin, I decided to get myself one. 

These highly polished slabs are difficult to photograph without getting a big reflection 

[MarcoSr]

11 hours ago, Tidgy's Dad said:

Tis a coral. 

It's all a bit confusing. There is a genus of green algae called Cladophora, that exists today and is found in Lake Michigan (and elsewhere)

Then there is the pachyporid tabulate coral of the same name found as fossils in the Lake Michigan area. (and elsewhere)

People get them muddled up.

I'm pretty sure this specimen is the latter. 

 

Thank you.  There were a number of sellers that had similar looking pieces from Michigan that were calling them fossil algae.  I wasn't sure, so I tried searching the web to verify.   The only results I could find for Cladophora were for algae.  I tried looking up pictures of algae fossils but really didn't find anything helpful.  Can you point me to any pictures or a paper on the tabulate coral named Cladophora?  I haven't seen a coral fossil that looked like this before (in a bunch of pieces in matrix versus a solid together structure).  Either way, I still really like the piece.

 

Marco Sr.

[Tidgy's Dad]

1 hour ago, MarcoSr said:

 

Thank you.  There were a number of sellers that had similar looking pieces from Michigan that were calling them fossil algae.  I wasn't sure, so I tried searching the web to verify.   The only results I could find for Cladophora were for algae.  I tried looking up pictures of algae fossils but really didn't find anything helpful.  Can you point me to any pictures or a paper on the tabulate coral named Cladophora?  I haven't seen a coral fossil that looked like this before (in a bunch of pieces in matrix versus a solid together structure).  Either way, I still really like the piece.

 

Marco Sr.

I am sorry, my error.

The genus you have there is Cladopora not Cladophora, but the rest of my comment still stands, it is these two that are often confused on the web. Including by me, it seems.

08/17/2006,09:22:33,"University of Michigan University Library",|PT07_002_ID190_00000016.TIF| (umich.edu)

Cheers,

Adam. 

[MarcoSr]

45 minutes ago, Tidgy's Dad said:

I am sorry, my error.

The genus you have there is Cladopora not Cladophora, but the rest of my comment still stands, it is these two that are often confused on the web. Including by me, it seems.

08/17/2006,09:22:33,"University of Michigan University Library",|PT07_002_ID190_00000016.TIF| (umich.edu)

Cheers,

Adam. 

 

Thank you for the paper and pointing out that the piece is coral not algae.  I'm disappointed the piece isn't algae, but it is still a nice piece.

 

Marco Sr.

[Tidgy's Dad]

1 hour ago, MarcoSr said:

 

Thank you for the paper and pointing out that the piece is coral not algae.  I'm disappointed the piece isn't algae, but it is still a nice piece.

 

Marco Sr.

Absolutely. A very nice piece indeed. 

[Wrangellian]

Ha.. I was just wondering if there was a thing called Cladopora, and started trying to search... but no need!

[Yoda]

Another from my collection 

 

 

[MarcoSr]

22 minutes ago, Yoda said:

Another from my collection 

 

 

 

I really like pieces like this.  I have the two small pieces below:

 

 25g 41x33x11 mm

 

 

38g 62x32x13 mm

 

 

 

and this larger piece is in the mail:

 

114g 128x51x8 mm

 

 

 

Marco Sr.

[Wrangellian]

Almost looks like you guys got two slices of the same rock!

Interesting stuff.

[MarcoSr]

Biogenic Sphalerite is formed by bacteria that live in places with water with low oxygen content where the bacteria combines zinc and sulfur from the water to create a byproduct of Sphalerite. Leis, Stinchcomb, Mckee, 2015, Stromatolites Ancient, Beautiful, and Earth-Altering

 

Schalenblende Sphalerite from the Pomorzany mine near Olkusz, Olkusz District, Milopoiskie Poland (248grams 109X60X9 mm):

 

 

 

 

 

 

 

 

Marco Sr.

[MarcoSr]

Oregon Bog Jasper is petrified swamp material (algae, moss, ferns, grass, wood and mud) that accumulated over millions of years, was then covered by volcanic ash and eventually became embedded with silica-rich minerals.  Leis, Stinchcomb, Mckee, 2015, Stromatolites Ancient, Beautiful, and Earth-Altering

 

Oregon Bog Jasper (a.k.a. Larsonite or Gary Green Jasper) slab from the Trout Creek Formation, Miocene 11 to 14 Million Yrs. Old, from McDermitt, Oregon  (600grams  8x5x.375 inches):

 

 

 

 

 

 

 

 

 

 

 

 

 

Marco Sr.

[Wrangellian]

On 5/21/2021 at 5:58 PM, MarcoSr said:

Biogenic Sphalerite is formed by bacteria that live in places with water with low oxygen content where the bacteria combines zinc and sulfur from the water to create a byproduct of Sphalerite. Leis, Stinchcomb, Mckee, 2015, Stromatolites Ancient, Beautiful, and Earth-Altering

 

Schalenblende Sphalerite from the Pomorzany mine near Olkusz, Olkusz District, Milopoiskie Poland (248grams 109X60X9 mm):

Interesting... I never realized there were so many things that could be considered stromatolites or at least related (biogenic mineral deposits etc).

 

[Wrangellian]

23 hours ago, MarcoSr said:

Oregon Bog Jasper is petrified swamp material (algae, moss, ferns, grass, wood and mud) that accumulated over millions of years, was then covered by volcanic ash and eventually became embedded with silica-rich minerals.  Leis, Stinchcomb, Mckee, 2015, Stromatolites Ancient, Beautiful, and Earth-Altering

 

Oregon Bog Jasper (a.k.a. Larsonite or Gary Green Jasper) slab from the Trout Creek Formation, Miocene 11 to 14 Million Yrs. Old, from McDermitt, Oregon  (600grams  8x5x.375 inches):

Ah, I think I have a couple pieces of this stuff - another thing that I received without info, and TFF steered me in this direction. You've given me more info that I did not have, too, so thanks! I've also seen it called 'Bog Wood'. I've always thought the one piece here that looks like wood (the end cut) must be wood, but I don't know. There are also chalcedony growths in the cavities. The other one I can see being a stromatolite.

 

One question though: is the site in Oregon or Nevada? I know the town straddles the border, but the info (maybe wrong) that I got for mine said Nevada.

 

The cut surfaces here have yet to be polished too (I've got a lot of such pieces), so I show them wet in pics 2 and 3.

Edited May 24, 2021 by Wrangellian
question

[MarcoSr]

8 hours ago, Wrangellian said:

Ah, I think I have a couple pieces of this stuff - another thing that I received without info, and TFF steered me in this direction. You've given me more info that I did not have, too, so thanks! I've also seen it called 'Bog Wood'. I've always thought the one piece here that looks like wood (the end cut) must be wood, but I don't know. There are also chalcedony growths in the cavities. The other one I can see being a stromatolite.

 

One question though: is the site in Oregon or Nevada? I know the town straddles the border, but the info (maybe wrong) that I got for mine said Nevada.

 

The cut surfaces here have yet to be polished too (I've got a lot of such pieces), so I show them wet in pics 2 and 3.

 

 

 

 

Really nice pieces especially the piece in the above picture.  The green color comes from ferrous iron minerals found in bog jasper which is somewhat unusual.  In one of the bog jasper pictures in Leis, Stinchcomb, Mckee, 2015, Stromatolites Ancient, Beautiful, and Earth-Altering the piece has a label with Nevada on it, and they say "McDermitt is an unincorporated community straddling the Oregon-Nevada border, thus the Nevada label".  So you can get pieces with either Oregon or Nevada as the collecting locality.

 

Marco Sr.

[Wrangellian]

OK, I'll write down both.

I have another piece of apparent pet wood that is tinted green - I wonder if it is from the same place. (pic not handy)

[Wrangellian]

Here's a site that explains some about the Larsonite/Bog Wood/Gary Green Jasper:

https://powershandcrafted.com/blogs/news/bogwood

 

I'm seeing others that say nothing of stromatolites, and that it may not even be wood, but banded rhyolite. Looking closely at my slab I'm not seeing any of the features that clinch it as wood. The other piece (the end cut) is more suggestive of wood, but I'm no expert so I'm not confident of anything here.

Edited May 25, 2021 by Wrangellian

[MarcoSr]

@Wrangellian 

Below is the excerpt from “Leis, Stinchcomb, Mckee, 2015, Stromatolites Ancient, Beautiful, and Earth-Altering” on Oregon Bog Jasper.

 

 

 

 

 

I have a number of pieces of this bog jasper and don’t see under magnification features that suggest wood.  Below are two pieces of petrified wood from Indonesia that were preserved by volcanic ash.  You can see the wood features in the magnified pictures.

 

 

 

 

 

 

 

 

Below is another piece of the Oregon Bog Jasper.  I believe my Oregon Bog Jasper pieces are a conglomerate of algae, moss, decayed grass, leaves and wood, and mud turned to stone.

 

 

 

 

 

 

 

 

Marco Sr.

[Wrangellian]

5 hours ago, MarcoSr said:

@Wrangellian 

Below is the excerpt from “Leis, Stinchcomb, Mckee, 2015, Stromatolites Ancient, Beautiful, and Earth-Altering” on Oregon Bog Jasper.

....

I have a number of pieces of this bog jasper and don’t see under magnification features that suggest wood.  Below are two pieces of petrified wood from Indonesia that were preserved by volcanic ash.  You can see the wood features in the magnified pictures.

...

Below is another piece of the Oregon Bog Jasper.  I believe my Oregon Bog Jasper pieces are a conglomerate of algae, moss, decayed grass, leaves and wood, and mud turned to stone.

Right... Other than my end cut piece, I don't see the finer characteristics of wood. Thing is, how do they know there is grass, moss, leaves, etc. if they can't see the features of those, either? All I see is layers/banding.

So the question becomes, what account for the banding? In some places the 'layers' are contorted, as in my other piece and some of yours. Just sedimentation, later distorted by compression/etc?

I'm torn between rhyolite or banded jasper. Or maybe chert?

 

On the other hand, I found this piece for sale at the usual venue. Yoda has seen it. It is very suggestive of stromatolite/microbialite (disrupted, like some of the Mary Ellen stuff and my 'snakeskin jasper' above), but again, I'm no expert. What do you think? I'm tempted to buy it but I can't really afford the exchange rate and shipping, so if you'd like to snag it, please do (save it from lapidarists who might chop it up!)   (You'll find it using any of the search terms)

Edited May 25, 2021 by Wrangellian

[MarcoSr]

50 minutes ago, Wrangellian said:

Right... Other than my end cut piece, I don't see the finer characteristics of wood. Thing is, how do they know there is grass, moss, leaves, etc. if they can't see the features of those, either? All I see is layers/banding.

So the question becomes, what account for the banding? In some places the 'layers' are contorted, as in my other piece and some of yours. Just sedimentation, later distorted by compression/etc?

I'm torn between rhyolite or banded jasper. Or maybe chert?

 

On the other hand, I found this piece for sale at the usual venue. Yoda has seen it. It is very suggestive of stromatolite/microbialite (disrupted, like some of the Mary Ellen stuff and my 'snakeskin jasper' above), but again, I'm no expert. What do you think? I'm tempted to buy it but I can't really afford the exchange rate and shipping, so if you'd like to snag it, please do (save it from lapidarists who might chop it up!)   (You'll find it using any of the search terms)

 

I definitely think that piece has something microbial going on.  Look at figure 9-16 in what I posted above.  I think the different chemicals (36 elements) that they found in the analysis give them some idea what might have been there.

 

Marco Sr.

[Wrangellian]

3 hours ago, MarcoSr said:

 

I definitely think that piece has something microbial going on.  Look at figure 9-16 in what I posted above.  I think the different chemicals (36 elements) that they found in the analysis give them some idea what might have been there.

 

Marco Sr.

Well, not knowing the details of the analysis, I'm not sure how they can tell what kinds of organisms went into it just by the elemental composition, which could have come from the ash, right? Where is the carbon?

I'm inquiring about the specimen in that auction... we'll see if there is any discount to be had, but I'm not holding my breath.

Edited May 26, 2021 by Wrangellian

[MarcoSr]

10 hours ago, Wrangellian said:

Well, not knowing the details of the analysis, I'm not sure how they can tell what kinds of organisms went into it just by the elemental composition, which could have come from the ash, right? Where is the carbon?

I'm inquiring about the specimen in that auction... we'll see if there is any discount to be had, but I'm not holding my breath.

 

I know with the coprolite paper that I was involved with the main author did a mineralogical analysis of one cylindrical coprolite utilizing X‐ray powder
diffraction because "advances in technology permit the identification of bacterial remains and internal inclusions" which are fundamental to the identification of the possible producer and these coprolites were 54 million years old.

 

Marco Sr.

[Wrangellian]

13 hours ago, MarcoSr said:

I know with the coprolite paper that I was involved with the main author did a mineralogical analysis of one cylindrical coprolite utilizing X‐ray powder
diffraction because "advances in technology permit the identification of bacterial remains and internal inclusions" which are fundamental to the identification of the possible producer and these coprolites were 54 million years old.

Marco Sr.

And this is what they did, and came to that conclusion, with the Larsonite? It might be a different story with something this altered vs. a 'pristine' coprolite.

 

I've been in contact with the seller of that piece I showed above, but they seem to be wedded to the global shipping program, which adds costs for me in Canada (on top of already-expensive shipping), so if you want to take a shot at it, go ahead. They did send me a lowered price offer but not really enough. Maybe they will do so for you. What is shipping like for you, domestically?

[MarcoSr]

1 hour ago, Wrangellian said:

And this is what they did, and came to that conclusion, with the Larsonite? It might be a different story with something this altered vs. a 'pristine' coprolite.

 

I've been in contact with the seller of that piece I showed above, but they seem to be wedded to the global shipping program, which adds costs for me in Canada (on top of already-expensive shipping), so if you want to take a shot at it, go ahead. They did send me a lowered price offer but not really enough. Maybe they will do so for you. What is shipping like for you, domestically?

 

It is $8 for domestic shipping.  It is a really nice piece, but I already have several examples.  Plus with it being rough, I would wind up polishing it by hand which is a real chore and I don't always get great results.

 

Edit:  Check out the below link on Gary Green Jasper.  This site has exceptional pictures and is run by a geologist with a bachelor’s and master’s degree in geology and who had a 40-year career as a geologist and geophysicist.

 

https://www.donwoolverton.com/gary-green-jasper

 

 

Marco Sr.

Edited May 27, 2021 by MarcoSr
added link