Jump to content
ober

algal mat?

Recommended Posts

ober

Hello all. I picked up this fossil in a Permian formation on the Potash Road, unpaved section, SW of Moab. I think I can eliminate what it is not but am unsure of what it is. I do not think it is some kind of sponge. It does seem to have the structure of coral. It does not it seem to be like any bryozoan clusters I’ve seen. If that is correct, this begins to narrow it to bacterial. The fossil material is very thin overlaying a hard red clay base, so I don’t think it is a stromatolite. It does not come in layers, but seems to be just one layer. The piece is 4cm x 4cm x 4cm. The fingers in the third picture give a good sense of scale. The most distinctive feature is the tooth like ridge just to the left of the red dot in the first picture. The second picture shows the thinness of the fossil level and the other pictures show the roughness of the surface. I wonder if it might be an algae mat of some sort. I looked at posts on the forum dealing with algae mats and similar and find things loosely similar but not conclusive to my untrained eyes. If it is an algae mat, it may be a fossilized cyanobacterial piece. At this point I’d like help just putting it into the broad category of what it is, which will direct further research.  More pictures available if anyone wants. If you have ideas, thanks for sharing. And if they come with some reference source, even better. Thanks. Tom

218B6291-0D03-4704-94CD-A574E1C4BDAF.jpeg

FA9BA503-9AF4-4AFE-B911-9BA2F3E315D5.jpeg

A6D7C1A7-4554-4957-872E-8DE238A68C37.jpeg

918D6C1F-C92E-4C61-8FA2-336ACE629CAF.jpeg

Share this post


Link to post
Share on other sites
abyssunder

Maybe you are referring to microbial mat? :headscratch:

Share this post


Link to post
Share on other sites
ober
1 minute ago, abyssunder said:

Maybe you are referring to microbial mat? :headscratch:

Thank you. I don’t know whether is is microbial, as in bacterial, or algae. Or something else. Any ideas?

Share this post


Link to post
Share on other sites
abyssunder

" Cyanobacteria are often the key organisms comprising microbial mats." link

Share this post


Link to post
Share on other sites
ober

 

26 minutes ago, abyssunder said:

" Cyanobacteria are often the key organisms comprising microbial mats." link

Thank you, this was a helpful citation. It suggests that cyanobacterial mats don’t commonly lithify due to their chemical composition. If that is the case, and was the case in the Permian, this is less likely to be a microbial mat segment. Therefore, perhaps more likely to be an algae mat? Or something else entirely? Progress, I think, but when I look at the tooth-like element in the first picture it is challenging to fit into an algae picture, unless the mat was laid down over something else that is coming through. 

Share this post


Link to post
Share on other sites
ynot

Although the pictures are blurred, I think this is a mineral deposit, not a fossil.

Share this post


Link to post
Share on other sites
abyssunder
18 minutes ago, ober said:
54 minutes ago, abyssunder said:

" Cyanobacteria are often the key organisms comprising microbial mats." link

Thank you, this was a helpful citation. It suggests that cyanobacterial mats don’t commonly lithify due to their chemical composition. If that is the case, and was the case in the Permian, this is less likely to be a microbial mat segment. Therefore, perhaps more likely to be an algae mat? Or something else entirely? Progress, I think, but when I look at the tooth-like element in the first picture it is challenging to fit into an algae picture, unless the mat was laid down over something else that is coming through. 

Hard to say for sure, but if it has a laminated structure built in a vertical stratified pattern, it might be stromatolite.

 

pdf

Share this post


Link to post
Share on other sites
abyssunder

modern microbial mats: modern stromatolite (Fig. 2. C)

 

retallack_2012_microbial_mat_and_earth-22khfla.thumb.jpg.31608681d86c86b0931a4db2712570f5.jpg

excerpt from here

 

(I'll go to sleep. It's time.) :)

 

Share this post


Link to post
Share on other sites
Innocentx

I can't tell from your photos, but do you see any pore-like structures?  

Share this post


Link to post
Share on other sites
ober

Thank you abyssinder and innocentx for these comments. I will look at the source and post hopefully better pictures this evening. I too went to sleep after you posted.  

Share this post


Link to post
Share on other sites
ober

Thank you abyssunder for the Retallack reference. I have several hopefully clearer pictures. The first two a similar and show detail of the surface. No sign of ‘pores’ that I recognize. The last two show the distinctive element on this sample, a ridge of items that looked like spaced teeth, although they are not teeth. I took these pictures with a macro lense and hopefully the surface is clearer. The red dot is just a reference point to the ‘teeth.’ There are two other locations on this sample with ‘teeth-like’ elements with the same orientation. These others are much weaker than that pictured. 

EC7A2DA6-30C9-440B-8F3B-EAA5750953CC.jpeg

0AB5FB67-C658-4B23-A93C-EEA7B58BA107.jpeg

703A8CF3-FE3A-4609-9CFD-0108861CF14F.jpeg

D15BE90F-5D50-4B94-A92A-03E0BE9B2B8E.jpeg

Share this post


Link to post
Share on other sites
DPS Ammonite

What is the top of the rock with the “teeth” made of? Could the teeth that are a different color than the rest of the rock actually be clasts?

See if it fizzes in acid and scratches with a knife blade.

 

If you know the formation that it came from, look for references that talk about the fossils.

 

Consider borrowing a microscope to get better up close photos. Some members at rock/fossil clubs have them. A thin section of the rock sent to an invertebrate paleontologist might help ID it.

 

I note that it looks a little bit like phylloid algae. See: http://www.thefossilforum.com/index.php?/topic/90712-possible-probable-reef/&tab=comments#comment-993532

 

I do not think that l have ever seen an algal or bacterial mat fossil nor could I ID one.

 

Thanks for posting this.

 

Share this post


Link to post
Share on other sites
ober

DPS Ammonite, thanks for these leads. I will pursue them. Tom

Share this post


Link to post
Share on other sites
I_gotta_rock

Unfortunately, I did not get any really close-up pictures of it when I was there last week, but Dinosaur Ridge in Colorado has a huge fossilized cyanobacteria mat exposed. Since they have at least one paleontologist there who knows about this stuff, you might want to try contacting the Friends off Dinosaur Ridge. Below is what their mat looks like. The orange, rippled area is where the mat was disturbed. They didn't mention what disturbed it, but it looks to me like something quite large stepped in it. There is a trackway from a whole herd of iguanodons maybe a hundred years from this spot.  

IMG_3136.jpg

Share this post


Link to post
Share on other sites
UtahFossilHunter

This paper says the area you were looking in has a lot of fossils in it. LINK The formations out there are the Rico Fm., Elephant Canyon Fm., and Halgaito Fm.

each of those have fossils in it. The Rico has a lot of bivalves in the uppermost part. The other two have a kind of hash of a little of everything.

b2000p.pdf

Share this post


Link to post
Share on other sites
ober

Thank you all for your recent comments. I have read suggested USGS paper and paper on microbial mats. So where do I stand? I am reasonable sure (95% probability) I have a fossil and not a rock formation. It is either Permian or Pennsylvanian, since there are different estimates for the age of the Rico Formation. Older is nice but I am more interested in clarifying this as bacterial or algal. This fossil was found on the surface and lighter material could have been eroded away, leaving the sculpted and harder surface I now have. The geology of the Paradox Basin is interesting and complicated. Microbial fossils can come in shallow layers as well as denser stromatolites. I have an idea of who else I can reach to for help. This will take more searching on my part to see if I can move towards greater certainty in an identification. I am enjoying the challenge and the search and particularly the help I’m getting from you on the Forum. Thanks. Tom

 

Share this post


Link to post
Share on other sites
abyssunder

Thank you for the pictures! :)

There are very interesting features.

I can see the "teeth" sticking out from the surface, but don't know what they might be.

Can you take a close-up picture focused on the area marked with red and a picture showing the lateral break surface which maybe has a layered appearance with cellular structure?

 

D15BE90F-5D50-4B94-A92A-03E0BE9B2B8E.jpeg.0aebc93a146edd8e0431e3ced2a77669.thumb.jpg.ed98b95c40731885f64027e14053a66f.jpg

 

 

Share this post


Link to post
Share on other sites
ober
52 minutes ago, abyssunder said:

 

I can see the "teeth" sticking out from the surface, but don't know what they might be.

Can you take a close-up picture focused on the area marked with red and a picture showing the lateral break surface which maybe has a layered appearance with cellular structure?

 

D15BE90F-5D50-4B94-A92A-03E0BE9B2B8E.jpeg.0aebc93a146edd8e0431e3ced2a77669.thumb.jpg.ed98b95c40731885f64027e14053a66f.jpg

 

 

Hello Abyssunder, here are some pictures that are in the area you requested. You see the ‘teeth’ to the right. Using a macro lense I don’t get very good depth of field. If these don’t work for you let me know and I’ll do it again. Thanks for thinking about this; I hadn’t paid much attention to the area in which you are interested but they do have a distinct character. Tom

89B8EF71-1A29-46CE-8D05-5DAD50E9A5E4.jpeg

AC29188D-61FA-41DB-806B-FED4EBC7A473.jpeg

35E12CC5-BF9C-4D6C-8537-3A4639563B29.jpeg

87444D66-CD19-4416-9F46-40F4D1AB38B5.jpeg

Share this post


Link to post
Share on other sites
abyssunder

Thank you for the new pictures. They are good.
I see clearly now that there is not the feature that I expected (multilayered and cellular). Those little "teeth" are intriguing, whatever they are.

Share this post


Link to post
Share on other sites
ober
31 minutes ago, abyssunder said:

Thank you for the new pictures. They are good.
I see clearly now that there is not the feature that I expected (multilayered and cellular). Those little "teeth" are intriguing, whatever they are.

31 minutes ago, abyssunder said:

Does the horizontal red layer suggest anything to you? The underside of the piece is not so clearly layered.

Share this post


Link to post
Share on other sites
abyssunder
2 hours ago, ober said:

Does the horizontal red layer suggest anything to you? The underside of the piece is not so clearly layered.

 

I'm not so versed in these, but the horizontal layer(s) may suggest iron oxide or other iron compound, which may be in the realm of microbial mats/microbial- induced sedimentary structures.

 

" Whether it formed at the base or top of the mat, Kinneyia is considered here a valid form genus for a distinctive form of microbial mat created by particular fluid and biological conditions on tidal flats, generally comparable with stromatolites (Grotzinger and Knoll 1999). Like Eoclathrus, which has a pustular rather than ridged morphology (Hantzschel 1975), Kinneyia is a useful parataxonomic name to express one form of sinuous to flexuous deformation of aquatic microbial mats. "

 

" Microbial earths are found in nonmarine sedimentary facies, whereas microbial mats form in lacustrine, floodplain, and marine sedimentary facies " - Retallack, 2012

Share this post


Link to post
Share on other sites
ober

Hello all,

 

I continue to be curious about this fossil. I’ve spoken to a marine invertebrate paleontologist and his opinion is that the is generally “encrusting bryozoan.” I also looked at it with a friend under several microscopes, including and electron microscope, which was interesting but didn’t really shed indentifying light on it. The scraping we took had lots of silica and the crystalline structure structure looked neat under different polarizing filters. It also had auto-fluorescent elements. At magnifications between 100 and 1000 times, we saw material that struck this biologist as cellular fragments. Structure was different from the silica crystals. She thought there were definitely biological elements in what we were seeing.

 

So here is where it stands. If anyone else takes a look and has additional thoughts I’d appreciate hearing about them. And thanks for all your suggestions to date. 

 

Tom

Share this post


Link to post
Share on other sites
Innocentx

Hi. @ober. I wish I could've seen what you got to, under the microscopes. I also share an interest in microbially induced structures in the fossil record.

They certainly aren't the 'celebrities' among the fossils but their indispensable supporting role deserves appreciation.

Share this post


Link to post
Share on other sites
ober
29 minutes ago, Innocentx said:

Hi. @ober. I wish I could've seen what you got to, under the microscopes. I also share an interest in microbially induced structures in the fossil record.

They certainly aren't the 'celebrities' among the fossils but their indispensable supporting role deserves appreciation.

I will post some pictures soon. By Sunday. I’ll be interested in what, if anything, they tell you. We took several pics, but not every image we saw. The ones between 400 and 1000 came out best. The ones of the actual surface, on a different scope, were not as helpful as the pictures I posted, at least to me.

 

And in the broader picture, I’m pursuing the encrusting bryozoan angle and reaching out to someone in Alberta to see if I can get confirmation or another lead. And I’ve been trolling the web. There is a current bryozoan, flustrellida hispida, that looks like if it was fossilized it could be a relative of my find. I haven’t found if it had a Permian ancestor yet, which of course it has, but I mean with images. 

 

Tom

Share this post


Link to post
Share on other sites
fifbrindacier

I agree with @ynot, i think this is geologic.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Recently Browsing   0 members

    No registered users viewing this page.

×