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Finis Shale, a New Type of Lagerstätte


BobWill

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About Lagerstatten, I have always understood it as it says in Wikipedia - two types: Konservat-Lagerstatte (exceptional preservation), Konzentrat-Lagerstatte (high concentration of fossils, not necessarily exceptional preservation), but a distinction is made to exclude intact communities such as reefs and oyster beds. I think the Finis would qualify as a Konzentrat-Lagerstatte because of the high-concentration. I guess the preservation is good too but not with soft-bodies.

Bob, I like your idea of a ratings scale for both quantities, or three quantities (concentration, preservation, and diversity). The ease of freeing the fossil from matrix is less meaningful, I think, except for collectors/preppers (maybe an optional 4th value).

Just brainstorming here:

Maybe 0-10 from unfossiliferous to chock-full (however that would be defined!) -for any given sedimentary unit (if the first value is 0 then the others would necessarily be 0 also)

1-10 for preservation might be 1 for poorly preserved and incomplete shells or bones, maybe 3-5 for intact but disarticulated or crushed, something higher than 5 for intact and not crushed, thru to 10 for soft-bodied. (Maybe 9 for soft-bodied but low detail, 10 for soft and highly detailed?) A coquina made of broken bits of shells/crinoids/etc I suppose would be low on the preservation scale but high on the concentration scale.

1-10 for diversity (however that would be graded) - maybe 1 for a single species to 10 for hundreds of them?

Of course determining a site's rating might be somewhat subjective but it would be less so than 'yes' or 'no', which I'm still unsure of where the dividing lines are. For coin/banknote and comic book grading, in recent years it has gone from highly subjective rough estimates to a much more refined art, almost a science. There are numbers associated with grades, such as (for coins) Good-4, Very Good-8, Fine-12, Very Fine-30... Mint-60, Mint-64 or 65.

I'd be curious to see how my local site/formation (the Haslam) would stack up against others, after this system has been implemented and refined! I guess it would be somewhere in the middle generally - maybe something like 4/4/5, ballpark estimate off the top of my head.

 

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  • 2 months later...

The paper describing the new lagerstätte is out but now I am confused about another designation mentioned in it. The Finis Shale is described as being an "Impregnation Lagerstätte (a type of conservation Lagerstätte), grading into liberation Lagerstätte."

They describe the new term, liberation but not impregnation so maybe someone here can clarify that.  The paper gives me a new number for the species count for Jacksboro, 292. That includes 259 species of animals and astonishingly, 1429 for the Triasic Cassian Formation of northern Italy. One interesting comment I noticed though is this:

"Excluding singletons, the most species rich fossil Lagerstätten by far are the Cassian Formation and the Finis Shale."

By singleton I assume they mean species only represented by a single example found.

 

 

 

Roden et al 2019_Palaeontology.pdf

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25 minutes ago, BobWill said:

The paper describing the new lagerstätte is out but now I am confused about another designation mentioned in it. The Finis Shale is described as being an "Impregnation Lagerstätte (a type of conservation Lagerstätte), grading into liberation Lagerstätte."

They describe the new term, liberation but not impregnation so maybe someone here can clarify that.  The paper gives me a new number for the species count for Jacksboro, 292. That includes 259 species of animals and astonishingly, 1429 for the Triasic Cassian Formation of northern Italy. One interesting comment I noticed though is this:

"Excluding singletons, the most species rich fossil Lagerstätten by far are the Cassian Formation and the Finis Shale."

By singleton I assume they mean species only represented by a single example found.

 

 

Roden et al 2019_Palaeontology.pdf

Your link did not work.

 

A search for “impregnation Lagerstatte” revealed a little info. It mentioned the the Buckhorn Quarry in Oklahoma is a lagerstatte that is impregnated and preserved by oil. The Finis Shale does not appear to be impregnated by anything similar. Maybe a reading of the paper might reveal more clues.

  • I found this Informative 1

My goal is to leave no stone or fossil unturned.   

See my Arizona Paleontology Guide    link  The best single resource for Arizona paleontology anywhere.       

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The Buckhorn Quarry deposit is the one being described as an impregnation lagerstatte, not the Finis Shale.

 

“The Pennsylvanian Buckhorn Asphalt Quarry deposits are a special, very rare type of Lagerstatte in which aragonitic shells are preserved due to early diagenetic impregnation by hydrocarbons...Impregnation Lagerstatten are a special type of conservation Lagerstatten and grade into liberation Lagerstatten.”

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My goal is to leave no stone or fossil unturned.   

See my Arizona Paleontology Guide    link  The best single resource for Arizona paleontology anywhere.       

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53 minutes ago, DPS Ammonite said:

The Buckhorn Quarry deposit is the one being described as an impregnation lagerstatte, not the Finis Shale.

 

Yep, I missed seeing that, but you missed seeing Table 3 on page 8 ;)

It shows the Finis Shale in the column "Type of Lagerstätte" with the same description.

 

I will ask Barbara what the Finis is impregnated with. I will probably have to wait for her to get back from Phoenix.

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19 minutes ago, BobWill said:

Yep, I missed seeing that, but you missed seeing Table 3 on page 8 ;)

It shows the Finis Shale in the column "Type of Lagerstätte" with the same description.

 

I will ask Barbara what the Finis is impregnated with. I will probably have to wait for her to get back from Phoenix.

I think that we found a mistaken description of the Finis. The Finis Shale is organic-rich dark shale in the bottom section, but I do not see any oil/asphalt in it. Bob, (or anyone else), have you seen any aragonitic mother of pearl in the Finis?

My goal is to leave no stone or fossil unturned.   

See my Arizona Paleontology Guide    link  The best single resource for Arizona paleontology anywhere.       

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9 hours ago, DPS Ammonite said:

I think that we found a mistaken description of the Finis. The Finis Shale is organic-rich dark shale in the bottom section, but I do not see any oil/asphalt in it. Bob, (or anyone else), have you seen any aragonitic mother of pearl in the Finis?

You may be right. In the article at the beginning of this thread the Finis is described as liberation lagerstätte rather than as "grading into liberation lagerstätte."

Unless someone knows of another reason to call it impregnated this would make a lot more sense if it was simply a mistaken entry in table 3.

 

edit: I just sent off an email to get some help with this from Dr. Seuss but I don't expect a rapid reply because of her trip to the U.S. coming so soon.

 

 

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9 hours ago, DPS Ammonite said:

I think that we found a mistaken description of the Finis. The Finis Shale is organic-rich dark shale in the bottom section, but I do not see any oil/asphalt in it. Bob, (or anyone else), have you seen any aragonitic mother of pearl in the Finis?

I already heard back from Barbara Seuss and she confirmed that the reference to impregnation was meant to only apply to the Buckhorn site and the Finis is a straight-up Liberation Lagerstätte. Good catch John!

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  • 5 months later...
On 7/6/2019 at 2:56 AM, Wrangellian said:

1-10 for preservation might be 1 for poorly preserved and incomplete shells or bones, maybe 3-5 for intact but disarticulated or crushed, something higher than 5 for intact and not crushed, thru to 10 for soft-bodied. (Maybe 9 for soft-bodied but low detail, 10 for soft and highly detailed?)

 

Having read this post, I think that it might be worth coming up with some sort of general rating system that could provide a quasi-standardized measurement of quality.  I have started a separate post here with a proposal for a rating methodology.  I'd welcome any comments.

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