MarcoSr Posted January 13 Share Posted January 13 (edited) I haven’t posted a stromatolite in a while. I’ve been preoccupied with biominerals and petrified wood. To see an old thread on stromatolites in my collection, check out the below link. The below stromatolite slab is one of my favorites in my collection because of its composition and formation story. This slab is a breccia created during a Mississippian time-period Impact (large meteor or asteroid) in Missouri that blended Cambrian aged laminar stromatolites with Precambrian aged iron. The close-up pictures below show the EDIT: agatized interdigital spaces of a stromatolite embedded in the iron. The last 5 pictures are at the highest magnification and show the stromatolite patterns and breccia patterns. Mississippian Impact Breccia Slab, Agatized Cambrian Laminar Stromatolite blended with Precambrian Iron, Crooked Creek Structure, Crawford Co., Missouri (264 grams 6.125x3.5x.375 inches): This slab was sold as fossilized coral. I could tell from the pictures that it was actually a stromatolite which I’ve confirmed with two stromatolite experts. The interesting thing is that it is from the Miocene of Indonesia. Both the time period and location make the specimen rare. Stromatolite Slab, Miocene, Indonesia (109 grams 3x2.75x.125 to .5 inches): Marco Sr. Edited January 17 by MarcoSr clarified what the inclusions are 1 11 "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted January 13 Share Posted January 13 Very beautiful. 1 1 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
jpc Posted January 13 Share Posted January 13 (edited) PM sent Edited January 13 by jpc 1 Link to comment Share on other sites More sharing options...
MarcoSr Posted January 13 Author Share Posted January 13 10 hours ago, jpc said: PM sent jpc You can repost your observations on the first piece. Other TFF members may be thinking the same. I'm fine with civil discussions/disagreements on specimen IDs. As I always tell my wife and sons "I may not always be right, but I'm never wrong " 🤣 I have a TFF thread on biominerals that probably 90% of the scientific community would think is total BS. I'm surprised TFF members haven't replied that. And I do see what you are observing and saying. Marco Sr. 1 "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
sharkdoctor Posted January 13 Share Posted January 13 Great pieces! Always fun to see where your interests have taken you. 1 Link to comment Share on other sites More sharing options...
Bobby Rico Posted January 13 Share Posted January 13 Lovely photos beautifully abstract forms . 1 Link to comment Share on other sites More sharing options...
jpc Posted January 13 Share Posted January 13 I posted this for a few minutes yesterday but removed it and sent it to marco sr in a PM. He has encouraged me to share my thoughts with you all in the name of fun discussions: cool stuff, marco. I regret to say that I don't see stromatolites in the first one. The 'stromatolitic' structures look more like layers of calcite like we see in many limey concretions. There is even calcite crystals on them. Stromatolites grow upward upon themselves as is well seen in the second one, but in the first one, there are a few places where the layered structures form cavity filling concentric layers. Also typical of calcite concretion infillings. In this photo, the stuff in the blues circle is not stromatolitic. Or am I looking at the wrong parts? I would call this brecciated calcite marco gave me a detailed answer which I will let him post here. 1 Link to comment Share on other sites More sharing options...
MarcoSr Posted January 14 Author Share Posted January 14 7 hours ago, jpc said: I posted this for a few minutes yesterday but removed it and sent it to marco sr in a PM. He has encouraged me to share my thoughts with you all in the name of fun discussions: cool stuff, marco. I regret to say that I don't see stromatolites in the first one. The 'stromatolitic' structures look more like layers of calcite like we see in many limey concretions. There is even calcite crystals on them. Stromatolites grow upward upon themselves as is well seen in the second one, but in the first one, there are a few places where the layered structures form cavity filling concentric layers. Also typical of calcite concretion infillings. In this photo, the stuff in the blues circle is not stromatolitic. Or am I looking at the wrong parts? I would call this brecciated calcite marco gave me a detailed answer which I will let him post here. Here is my PM answer to the above: "jpc This specific piece was collected by Dr. Bruce Stinchcomb, an early world renowned expert on Stromatolites and the author of the book "Stromatolites, Ancient, Beautiful, and Earth Altering." Dr Stinchcomb was a professor of geology. Unfortunately, Dr. Stinchcomb passed away last year, or I would ask him to respond to your observations. Dr. Stinchcomb collected and gave a block of the breccia from the impact site in Missouri to Dan Damrow, who does lapidary work, to cut into slabs and polish. Dr. Stinchcomb identified the breccia block as "Cambrian aged laminar stromatolites blended in with Precambrian aged iron formed by a large meteorite/asteroid impact". He also had the advantage of looking at unaltered rock layers in the immediate impact area. Dan, a good friend of mine, is probably the most well know stromatolite, non Dr. expert, in the US because he has collected, cut, polished and sold throughout the US for over 30 years stromatolites from all over the world. This piece came directly from that block to me out of Dan's personal collection. There is a YouTube video where Dr. Stincomb describes a number of geologic anomalies in Missouri and attributes the geology to this large meteor/asteroid impact. I should have taken and posted a lot more pictures of the distortions in this piece. I see lots of rock slabs under the microscope including agate, calcite, chalcedony, etc. and this piece has areas that I just don't usually see. With the piece being formed in an impact event under high temperatures and pressures, there is a lot of distortion of the stromatolites, To me a lot of the inclusions look like crazy lace banded agate which isn't a stromatolite but just agate. Or banded calcite. If you believe Campos-Venuti and his book, banded calcite is biogenically influenced but is not stromatolitic either. But then there are inclusions that very look similar to laminar stromatolites. I have no problem if you make your post. This piece may be confusing due to the stromatolite inclusion distortions to a number of TFF members, and they can make their own determinations. Due to the provenance of this piece, and the stromatolite knowledge level of the involved people, I'm in the distorted stromatolite inclusion camp." Here is a second PM answer: "jpc I'm not 100% convinced myself. If it is stromatolitic, it is wavy or wrinkled laminar, not the more common smooth laminar. The slab is non-magnetic metallic brown, which I believe is Hematite (I need to do a streak test in my toilet tank). Checking on-line, Crooked Creek is an impact area and Crawford County has lots of Precambrian Hematite being mined. Plus, there are a number of old papers talking about different stromatolite layers in the area. I also saw a video on-line where Dr. Stinchcomb was describing the Crooked Creek impact. So the story seems to check out on the piece." So bottom line, the inclusions are not what I would call typical looking stromatolites, but I believe the stromatolites were altered by the impact. Either way, the piece is definitely an iron breccia formed by a large meteor/asteroid impact, and the piece is definitely interesting under the microscope. Marco Sr. 7 1 "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
jpc Posted January 16 Share Posted January 16 Does no one have any thoughts on this besides marco and I? Link to comment Share on other sites More sharing options...
Al Dente Posted January 16 Share Posted January 16 21 minutes ago, jpc said: Does no one have any thoughts on this besides marco and I? I'm convinced the region you circled is mineral growth. 1 Link to comment Share on other sites More sharing options...
MarcoSr Posted January 17 Author Share Posted January 17 10 hours ago, Al Dente said: I'm convinced the region you circled is mineral growth. Eric Do you think the mineral growth is pre impact or post impact? Do you think all the inclusions are mineral growth? Marco Sr. "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
MarcoSr Posted January 17 Author Share Posted January 17 On 1/16/2024 at 10:54 AM, jpc said: Does no one have any thoughts on this besides marco and I? 23 hours ago, Al Dente said: I'm convinced the region you circled is mineral growth. I asked Dan about the slab, stating that the inclusions looked like crazy lace agate or banded calcite, and this is what Dan responded: "You are looking right at the strom. It is completely agatized. I can’t find a larger single dome that I did but here is a pic of stromatolite in which (we presume) all the interdigital spaces are agatized." I have a few more of these. So, Missouri Lace Agate and Crowley Ridge Agate are both agatized stroms for sure. I have the other half of my dome still in my shop as an unfinished slab. And lots more rough to deal with." Wow, so I definitely learned something. So the inclusions in the slab in question are agatized interdigital spaces of a stromatolite. Edit: Update from Dan: "Here is the dome that I did several weeks ago. The whole sequence of this strom and its alteration is well documented in a Missouri state bulletin but it would take some time to dig it up again as I did not save it." Marco Sr. 2 1 "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
MarcoSr Posted February 9 Author Share Posted February 9 I just received 5 stromatolite slabs from Indonesia (See the first two pictures below, showing both sides). I’ve bought a lot of material from Indonesia directly over the years and check the different places where Indonesian sellers advertise often. I’ve only seen stromatolite pieces two times and bought them both times, so Indonesian stromatolites don’t come up for sale often. They may be rare or just not sold for some reason. I’m keeping three of the 5 slabs and sending two to my friend Dan. Below also are some individual pictures of a slab I’m keeping. Stromatolite, Kalimantan, Island of Borneo, Indonesia (75 grams 3.25x1.75x.250 inches) Marco Sr. 1 "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
Yoda Posted February 9 Share Posted February 9 @MarcoSr Those are nice. And unusual 1 MotM August 2023 - Eclectic Collector Link to comment Share on other sites More sharing options...
Polybranchiaspidida Posted February 11 Share Posted February 11 They are all very beautiful, maybe one day I will also have one. 1 A tourist from the distant East who is full of curiosity about everything.I am very much looking forward to anyone's reply. Come to view my collection topic: https://www.thefossilforum.com/topic/138618-the-growing-collection-of-polybranchiaspidida/ The wind can blow out candles, but it can make wildfires burn louder and louder. Gravity is not only unique to Earth, but also exists between the universe. Link to comment Share on other sites More sharing options...
MarcoSr Posted Tuesday at 07:30 PM Author Share Posted Tuesday at 07:30 PM I finally convinced my friend Dan to trade an agatized stromatolite from Missouri to me. I had to trade two rare, small, blue stromatolite slabs from Indonesia (See above for examples that I kept). This piece is loaded with interesting banding and other features that are hard to see in detail in the individual face picture, so I took a number of close up pictures going down the stromatolite face in order. Agatized Stromatolite End Cut, Upper Cambrian, Potosi Formation, Barite Mines, Washington County, Missouri (977 grams 6.25x3.25x2.375 inches): Marco Sr. 1 "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
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