Stromatolites

[FranzBernhard]

Thanks for all the info on that supposed malachite slab and all those awesome Kona dolomites.

5 hours ago, MarcoSr said:

that you can get variation in color

In malachite - not really. First thing I would to with such an untypically colored malachite is to XRD it, or to do some other mineralogical or chemical tests.

Franz Bernhard

[MarcoSr]

1 hour ago, FranzBernhard said:

Thanks for all the info on that supposed malachite slab and all those awesome Kona dolomites.

In malachite - not really. First thing I would to with such an untypically colored malachite is to XRD it, or to do some other mineralogical or chemical tests.

Franz Bernhard

 

I did look at a lot of Malachite pieces online and did buy this piece because it definitely looked unique.  I'll check with different museum folks that I know to see if any of them can help me to get an XRD analysis on the piece.   I had just assumed that the piece came from a slightly different Malachite deposit in a different part of the Tantara Mine.

 

Marco Sr.

[Wrangellian]

Those Kona pieces look great! I've heard the name but never knew much about it nor seen classic examples such as these.

[FranzBernhard]

9 hours ago, MarcoSr said:

I did look at a lot of Malachite pieces online and did buy this piece because it definitely looked unique.  I'll check with different museum folks that I know to see if any of them can help me to get an XRD analysis on the piece.   I had just assumed that the piece came from a slightly different Malachite deposit in a different part of the Tantara Mine.

Yeah, its different and that makes it so interesting! Its special either way: If it is not malachite or if its pale malachite. Hope, you can get some analytical results, would be very interesting to know it - any result would be a surprise!

Franz Bernhard

[MarcoSr]

On 4/26/2021 at 4:00 AM, Wrangellian said:

 

You're getting some nice pieces of everything, Marco. I don't know how you do it, though I suspect money is involved...  Somehow I missed this one when you first posted it. I have 8 pieces of MEJ and none of them are quite as good.

 

 

Here is a special piece of Mary Ellen Jasper.  It came from the personal collection of the late Robert Wiekert.  I was told that Robert only polished a couple of pieces of Mary Ellen Jasper from this Mary Ellen Jasper layer.  His passion was the digitate pieces.  This piece has both laminar and domal stromatolites.

 

Mary Ellen Jasper, laminar and domal forms, Precambrian 1.88 Billion, Biwabik Formation, Mary Ellen Mine, St. Louis Co., Minnesota (8.25 lbs. 9.25x7.75x1.375 inches):

 

 

 

 

 

 

 

 

 

Marco Sr.

[digit]

Beautiful stuff!

 

 

Cheers.

 

-Ken

[Wrangellian]

12 hours ago, MarcoSr said:

Here is a special piece of Mary Ellen Jasper.  It came from the personal collection of the late Robert Wiekert.  I was told that Robert only polished a couple of pieces of Mary Ellen Jasper from this Mary Ellen Jasper layer.  His passion was the digitate pieces.  This piece has both laminar and domal stromatolites.

Mary Ellen Jasper, laminar and domal forms, Precambrian 1.88 Billion, Biwabik Formation, Mary Ellen Mine, St. Louis Co., Minnesota (8.25 lbs. 9.25x7.75x1.375 inches):

Marco Sr.

 

You're doing well with the macrophotos...are you using a scanner or just camera/cellphone?

I'm thinking about starting a separate thread to show off my stroms, or maybe we could make a communal "Show us your stromatolites" thread - I don't think there is one yet? I still need to get some of them polished but I could just photo them wet for the sake of getting the thread going sooner.

 

Your piece reminds me of the brecciated stuff... it looks like it's borderline brecciated. I have a couple like that, with at least one dome evident.. see below. I always figured this was the beginning of the digitate structures, but maybe not. They come from distinct layers? Which layer is above which, I wonder. And if the digitate ones are Collenia undosa, would these be called something else?

I saw a piece online that is called MEJ but it is more of a layered or larger-scale dome structure that is semi-broken up. Looked rather unusual, and I'm still tempted to get it, but hate to spend money I don't have much of, esp. with shipping as it is these days. Yoda knows the one I mean.

 

Here is mine:

I don't know if you would call the clumps 'oncolites', but there is also a dome apparent in the 2nd pic, and I guess those are ooids filling all the gaps...

 

Edited April 29, 2021 by Wrangellian

[MarcoSr]

18 minutes ago, Wrangellian said:

 

You're doing well with the macrophotos...are you using a scanner or just camera/cellphone?

I'm thinking about starting a separate thread to show off my stroms, or maybe we could make a communal "Show us your stromatolites" thread - I don't think there is one yet? I still need to get some of them polished but I could just photo them wet for the sake of getting the thread going sooner.

 

Your piece reminds me of the brecciated stuff... it looks like it's borderline brecciated. I have a couple like that, with at least one dome evident.. see below. I always figured this was the beginning of the digitate structures, but maybe not. They come from distinct layers? Which layer is above which, I wonder. And if the digitate ones are Collenia undosa, would these be called something else?

I saw a piece online that is called MEJ but it is more of a layered or larger-scale dome structure that is semi-broken up. Looked rather unusual, and I'm still tempted to get it, but hate to spend money I don't have much of, esp. with shipping as it is these days. Yoda knows the one I mean.

 

Here is mine:

I don't know if you would call the clumps 'oncolites', but there is also a dome apparent in the 2nd pic, and I guess those are ooids filling all the gaps...

 

 

 

 

Really neat piece.  I think what you are seeing in your piece are called thrombolites which have broken or clotted laminae.  Some researchers question whether thrombolites are unique structures or just disrupted stromatolites.

 

There are a number of other stromatolite forms.  Laminar or planar stromatolites are also referred to as Stratifera.  Domal stromatolites are also referred to as Cryptozoan.  The conical morphology are referred to as Conophyton.

 

I take my macro pictures with a regular camera and my micro pictures with my digital microscope.

 

If you start a "Show us your stromatolites" thread I'll put mine there instead of this thread.  I have a number of different ones I could add that aren't in this thread.  I wouldn't add the ones in this thread again but just put a link to this thread and my oncolites thread.

 

Marco Sr.

[Wrangellian]

Right, your micro pics. Seems like a digital microscope is the thing to have for this sort of thing, but my 'macro' lens works pretty well for magnification too, or the scanner.

 

OK, we could start another thread... if you'd like to do it, go ahead, or else I will do it once I get some pics. I might need to wait for some sunshine up here to get decent photos with the camera.

 

What I'm still unclear on is, they have that gen/species name (C. undosa) for the stroms from the Mary Ellen mine, but the other names you mention seem to be broader terms descriptive of the structural categories, such as Conophyton for conical shapes. I have a piece from the Mary Ellen mine which I would guess is conical, actually a series of cones making zigzag patterns. Would this be Conophyton, or just a variation of the local Collenia undosa (or Collenia sp. or Conophyton sp.)?

Here it is:

It resists water so I took the pic dry. It will look better when I get it polished.

Edited April 29, 2021 by Wrangellian
addition

[Yoda]

7 hours ago, MarcoSr said:

If you start a "Show us your stromatolites" thread I'll put mine there instead of this thread.  I have a number of different ones I could add that aren't in this thread. 

 

I would have a few to add too 

[MarcoSr]

5 hours ago, Yoda said:

I would have a few to add too 

 

12 hours ago, Wrangellian said:

Right, your micro pics. Seems like a digital microscope is the thing to have for this sort of thing, but my 'macro' lens works pretty well for magnification too, or the scanner.

 

OK, we could start another thread... if you'd like to do it, go ahead, or else I will do it once I get some pics. I might need to wait for some sunshine up here to get decent photos with the camera.

 

What I'm still unclear on is, they have that gen/species name (C. undosa) for the stroms from the Mary Ellen mine, but the other names you mention seem to be broader terms descriptive of the structural categories, such as Conophyton for conical shapes. I have a piece from the Mary Ellen mine which I would guess is conical, actually a series of cones making zigzag patterns. Would this be Conophyton, or just a variation of the local Collenia undosa (or Collenia sp. or Conophyton sp.)?

Here it is:

It resists water so I took the pic dry. It will look better when I get it polished.

 

@Wrangellian  Nice piece!  I'll wait for you to start the Stromatolite thread.  The thread will give you incentive to take more pictures and give both @Yoda and me a place to post our stromatolites.

 

I’ve seen columnar (digitate) stromatolites called Collenia-type and also seen Collenia used as a genus.  Your piece looks like it has Collenia-type stromatolites versus Conophyton-type.  See the below figure from Leis, Stinchcomb, Mckee, 2015, Stromatolites Ancient, Beautiful, and Earth-Altering for Conophyton-type.

 

 

Marco Sr.

[MarcoSr]

This post is to respond to the comments: “OK. The pic is maybe a little deceptive from this end without a scale but I'll take your word for all that. I don't mean to be argumentative. ……….. I'm not about to suggest you remove the piece from the topic!”

 

Here is the picture.  I don’t include a scale in the pictures that I take and in the hundreds/thousands that I have posted here on TFF.  I’m more interested in the aesthetics of the specimen and don’t want to diminish that with scales.  I include dimensions in the text.

 

 

 

 

I was unable to retake the above picture with my microscope because of the jury-rigged set-up that I used doesn’t allow me to balance a ruler on the thin edge of the piece. So I recreated the same basic picture laying the piece flat on a table and taking the below pictures with my camera.

 

Here is the piece.  What was being discussed in the other thread was whether or not the piece showed evidence of a microbial mat which I stated in my original reply that I was not sure of.  I then found a paper “Porada  Ghergut Bouougri 2008 Kinneyia-type wrinkle structures - Critical review and model of formation” that gave a good number of features for microbial mats and specifically Kinneyia-type wrinkle structures that indicated a microbial mat.  The piece matched the features in the paper and the above picture was used by me in the thread to try to show what I was saying in words.  I included the yard stick and ruler in the below picture so the size of the piece and the widths of the crests in the wrinkle pattern can be seen and measured.  The red arrow points to the exact area where the original microscope picture was taken and the below additional camera pictures were taken.  Note that the widths of the crests in this area are some of the widest in the piece.

 

 

 

 

Here are the two new camera pictures with a ruler with a millimeter scale showing the exact area of the original microscope picture.  The first picture shows the height/amplitude of the wrinkle which I had said in words was 2mm in the thread.  The next picture shows the intercrest distance which is a bit larger than 3mm.  The paper states Wrinkle structures are on a millimeter scale and, in most general terms, are characterized by ‘‘oddly contorted, wrinkled, irregularly pustulose, quasi-polygonal, commonly oversteepened surface morphologies that can occur on bed tops and bottoms’’ (Hagadorn and Bottjer, 1999, p. 73). Despite this highly conceptualized definition, wrinkle structures frequently reveal patterns of more or less regular troughs and crests with amplitudes in the range of 0.3–3 mm and intercrest distances of 1–5 mm, sometimes resembling miniature interference ripples.  The crests are flat on top (A feature which matches the paper) and relatively steep sided (the paper states  “oversteepened” and “steep-to-almost-vertical flanks of the crests”).  The crest tops are in the same plane.  So basically to me these pictures show features consistent with microbial mats.

 

 

 

 

 

Whether or not the piece showed evidence of a microbial mat wasn’t what was important to me.  The discussion about microbial mats and learning from that was.

 

Marco Sr.

Edited December 15, 2023 by MarcoSr
Softened language

[FranzBernhard]

1 hour ago, MarcoSr said:

And most likely this is my last post/reply on TFF.

 Whats going on here??
Franz Bernhard

[Wrangellian]

17 hours ago, MarcoSr said:

This post is to respond to the comments: “OK. The pic is maybe a little deceptive from this end without a scale but I'll take your word for all that. I don't mean to be argumentative. ……….. I'm not about to suggest you remove the piece from the topic!”

 

Here is the picture.  First of all, I don’t include a scale in the pictures that I take and in the hundreds/thousands that I have posted here on TFF.  I’m more interested in the aesthetics of the specimen and don’t want to diminish that with scales.  I include dimensions in the text.

...

Whether or not the piece showed evidence of a microbial mat wasn’t what was important to me.  The discussion about microbial mats and learning from that was.  I was here on TFF to relax, enjoy, learn and to maybe help others, not to have to make a reply post like this.  I will not return to that other thread.  And most likely this is my last post/reply on TFF.

Marco Sr.

I don't know if you read my reply on the other topic but I wanted to make sure you knew that you misread or misunderstood the intent behind my comments completely. If I had known you were going to take them that way I would not have said them, I would have just said "Interesting... thank you for posting" but I was not quite convinced and had to question things. You did not have to prove anything to me, and I'm sorry if I led you to believe you were in the hot seat or anything like that. The last part of the comment you quoted above was not in any way a suggestion that you should remove the pics. It was just a tongue-in-cheek sort of way of saying it was welcome in the thread, whatever it happened to be. I was already 90% convinced that thing is MISS and the more I look at it the more convinced I am. It looks too irregular for wave ripples.

Anyway, please don't quit the forum just because of me. That would not be fair to me or to anyone else. I am only one person who doesn't really matter.

[Coco]

Hi,

 

@MarcoSrI’m sorry you want to leave this forum. You are such a resource of knowledge in various fields that we will miss you too much. If you leave, I would feel punished not to read you anymore. I hope you reconsider your decision my friend.

 

Coco