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Showing results for tags 'stromatolite'.
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This silicified lacustrine Miocene stromatolite is a trace fossil made by a gram-negative photosynthetic blue-green bacteria. The originally limestone stromatolite was formed as a bacterial mat trapped sediment and precipitated limestone as it grew from the lake floor towards the sun. It shows classic convex layering towards the top. The stromatolites occur in tuffaceous and lime rich lake sediments that might be part of the Chalk Canyon Formation that is bounded on the bottom by basaltic lava and volcanic rich conglomerate and sandstone on the top. Locally numerous silicified casts and molds of reed like plants, their roots, and palm wood occur in the lacustrine sediments. Since the area is under possible scientific investigation I will not give a more specific locality. The Arizona Museum of Natural History has fossils from the site per my showing them the site. The taxonomy is very unsettled as is the author of Cyanobacteria. Taxonomy per International Registry of Marine and Nonmarine Genera: https://www.irmng.org/aphia.php?p=taxdetails&id=110 See also: https://link.springer.com/article/10.1007/s10750-014-1971-9 “The cyanobacteria are named under Botanical and Bacteriological Codes, and the usage of both systems at the same time causes considerable confusion as the rules of the Botanical Code are quite different from those of the Bacteriological one.” Photo 1: detail of photo 2. Photo 2: 9” wide polished cross section cut and polished courtesy of Stan Celestian. Photo 3: 6” wide polished cross section of another side. Photo 4: top of colony. Photo 5: bottom of colony. Fossil Cyanobacteria & stromatolite overview: https://ucmp.berkeley.edu/bacteria/cyanofr.html Interesting paper that suggest Cyanobacteria created calcified structures because of interactions with viruses: White, R. A., 3rd, Visscher, P. T., & Burns, B. P. (2021). Between a Rock and a Soft Place: The Role of Viruses in Lithification of Modern Microbial Mats. Trends in microbiology, 29(3), 204–213. https://doi.org/10.1016/j.tim.2020.06.004 https://newsroom.unsw.edu.au/news/science-tech/stromatolites-–-fossils-earliest-life-earth-–-may-owe-existence-viruses
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- arizona
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Got the itch to collect and study some stromatolites, so I did some searching and feel that I successfully scratched the itch. I found a section of the Cambrian Copper Ridge dolomite that exposes a plethora of stromatolites of various morphologies. Many of them look as if they are straight out of Shark Bay in Australia, with the characteristic domal structure attached to a thinner holdfast on a hard substrate. Stromatolites are formed over a long period of time in tidal zones by colonies of photosynthetic bacteria and/or algae that form sticky layers that trap sediments and concrete them into layers. The colony then grows over the older, cemented colony and the cycle repeats itself. The process is obviously a lot more complicated than that, but I digress. Stromatolites are the oldest confirmed fossils to have been discovered, with the current oldest ones to be confirmed coming from the Strelley Pool Chert formation in Western Australia, dating back to the early Archaen at approximately 3.4 billion years ago. At that point in time, the Earth's atmosphere was largely devoid of oxygen, primarily being composed of CO2. Over the next several billion years, these stromatolites were largely responsible for oxygenating the atmosphere. They may not look like much, but these bacterial colonies were extremely important to creating Earth's biosphere. After the Cambrian explosion, stromatolites began to become quite rare in the fossil record, with multicelluar organisms feeding on them and disrupting the cementation process. After that point and to this day, stromatolites primarily thrive in extreme environments were the animals that feed on them cannot survive. The stromatolites in the Shark Bay, Australia area live in a hypersaline environment created by a seagrass barrier just off the coast. Unfortunately climate-change induced increases in precipitation are causing floods that reduce the salinity of this location and threaten the survival of the stromatolite colonies. With that information, enjoy these photos of stromatolites. Cube scale is 2cm on each side Large domal type in the position it would have grown in: Another domal type, almost spherical in shape, composed of multiple separate colonies that appear to have fused together: Another domal type: Cross section of broken laminar piece showing growth layers over an oolitic limestone substrate: A different one, I hope to polish this face: Layers under microscope:
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A friend cut a polished a silicified lacustrine Miocene stromatolite from central Arizona that I found. Thanks Stan C. It is about 8 inches in maximum length. Two faces were cut that show the upward convex growth. I am currently looking for a researcher to help write a paper about these and the other plant fossils that occur in the area. A piece that was cut from the same colony as this piece is being donated to the Pinal Geology Museum in Coolidge, AZ. https://pinal geology museum.org Another Arizona museum wants one. I am seeing if other local institutes want one. Top of colony. Bottom. Side. Side. Detail.
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From the album: Miscellaneous
Found in the Red River/Lake Texoma. Likely from the Cretaceous-aged Paw Paw Fm. ~ 100 Ma.-
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I went to the aquatics shop this morning to buy some fish food. They were selling these rocks as decor. Person helping me had no idea re provenance. I think they are geologic in origin. But with the banding was thinking there is an outside chance they could be Stromatolites About hand size.
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Two highly polished, end cut Stromatolite agate achats from the Mátra mountains, Gyöngyöstarján, Hungary from the Miocene, 20 million years ago that I recently purchased. These are the first Stromatolite fossils that I’ve added to my fossil collection. I’m posting a few pictures to show the incredible colors in these pieces. End Cut (1) ( 543grams 103mm by 102mm by 35mm) End Cut 2 (166grams 75mm by 45mm by 45mm) Marco Sr.
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Hi, I found this stone in...a charity shop. I really love it but I’m not sure what type of stone it is and the only one I can connect it to would be stromatolite. It has more unusual pattern though. Please could someone help me with identification. It has a clear quartz (I think) in the middle, it should be visible on the photo. Thanks
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Hello all, & Thank you in advance. I was wondering if you could help me ID this Stromatolite species or location it could be from, it was a random buy & fair price, though it was only labeled as a Australian Stromatolite. I've looked at a Australian dealer that sells a wide range of AU stromatolites. I'm not coming up with a clear match that says this is it, I know stromatolites can vary some to a lot in a species & locality. Australian or some other location around the world ?
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Hi I was wondering what your opinions are on these if they're real or fake, or any work done on them ? There's two of them. Labeled as - Lacustrine Stromatolite colony's, no work done on them. First - from the Permian age, Lauterecken formation, Germany Second - from Oligocene age, Rhineland Germany
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From the album: Miscellaneous
A section of a stromatolite from the Strelley Pool Chert, Western Australia. Currently, these stromatolites are among, if not the oldest known fossils. There is possibly earlier evidence of life in the form of biogenic carbon, but this chert produces the oldest known mineralized preservation of organisms. Of course everyone wants to find the "earliest life," and it becomes difficult to differentiate between microorganisms and geologic structures in rocks so old, so there will always be disagreement and competition. Likely, there are older fossils already found or yet to be, but it requires a large amount of evidence and arguing to form some consensus. From what I've seen, this appears to be the most widely accepted "oldest fossil." Perhaps as (or more) interesting is what we can apply from the debate to searching for evidence of life on other worlds ... More info: "Strelley Pool Chert and Early Life" [NASA] "A Rare Glimpse of Paleoarchean Life: Geobiology of an Exceptionally Preserved Microbial Mat Facies from the 3.4 Ga Strelley Pool Formation, Western Australia" [NCBI] "World's Oldest Fossils Found in Ancient Australian Beach" [Science Magazine] "Stromatolite reef from the Early Archaean era of Australia" [Nature] "Controls on development and diversity of Early Archean stromatolites" [PNAS]-
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Hello again Fossil Forum, Last week I posted a few pictures of what I thought might be fossil wood that I found on my property in Southeastern PA (Montgomery County, just over the Philadelphia County line). It seemed that it was possible that my rocks were fossils, but also maybe not... One helpful user suggested that I might polish some of the ends (hopefully crossections) of a few pieces. So below and in the next few replies I will post some pictures of a few pieces, for the polished parts I used a cabbing machine. I live at the bottom of a relatively steep hill and these pieces were all found within about 50ft of each other. If there seems to be some variety, that is in keeping with what I found after consulting several geological maps of my area: my property appears to lie at the precise intersection of precambrian, lower paleozoic, and cambrian regions and includes both sedimentary and metamorphic rocks. If not fossil wood, possibly stromatolites? ...or just more interesting rocks?? For discussion purposes I'll number the pieces and put them in separate replies. Thank you again for any thoughts, information, and opinions!
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I am heading to Herkimer for a trip soon, and I was wondering if anyone knew any places one could find fossils? I heard some of the mines have stromatolites but I could not find much information on that. I also hear about trilobites near the diamond mines, and I hope to find some, and if anyone has any advice that would be appreciated.
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Hi everyone Surface find in SW Arizona that I would like to ID if possible. I believe this is Stromatolite and it appeared to have a shark, Ray or Skate egg sack on it so I brushed some synthetic oil on it and put it under the microscope. looks like something inside there to me. My first thought is Xenacanthus although whatever that is in there doesn't really match up that well. Complete newbie here asking is this Stromatolite ? and what is that in the egg sack ?. Finding Graptolites, Arthropod's and Stromatolite in the same areas.
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Stromatolite? Found in Silurian reef. Thanks for any help..
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I found this a while back, and now I'm wondering if it could be a stromatolite. Though, it could just be some sedimentary formation. It was found in the red river/lake texoma in texas. Any thoughts or insight would be much appreciated, thank you! In the second photo, I sanded a bit of the side to show the layering.
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Hello, everyone, I’m newly retired after 39 years of teaching. Over the years, I have collected, by purchase, to use as demonstration pieces in the classroom a wide collection ranging from Archean microbial mat cross-sections through time to Holocene cave bear vertebrae. My collection is very diverse through time, if limited in depth. I have a nice collection of Silurian-Devonian trilobites, some nice Devonian-Permian plant material, and a range of Holocene mammal bones; vertebrae and mandibles. ... I taught a variety of upper level secondary courses over the years. As Science Dept. Chair in an independent school, I oversaw curriculum (shorthand for “I got to teach what I loved) For many years I taught an Natural History course to seniors looking at the evolution of the Universe. First term Cosmology-Planetary Science; Second term Evolution of Life. A dream job. Now, I’m trying to complete a more formal indexing of my collection (which includes MANY casts as well). Nice to find you folks. Probably will be an infrequent visitor. Glenn
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While hiking through a desert area just southwest of Tucson, AZ. I found these interesting layered rocks. Over the course of an afternoon I came across a couple more spots where these types rocks were strewn over relatively large areas. Many of the pieces would fit inside a square inch or the palm of your hand, while many others were a few feet long/wide. I showed these to a local geologist and he called them stromatolithic Paleozoic limestone – evidence the area was once covered by water and these represent the layers of algae, probably in the form of algal matting that existed there, dating back to the Paleozoic time period. Respectfully, can anyone confirm or negate this idea? Thank you for your time and consideration!
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Found in northwestern New Mexico in an Upper Cretaceous area. Specimen was wetted with water to bring out detail.
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Found a few beautiful pieces in rocks dug up by the local water department.surface exposure is Gasconade dolomite so i assume these are actually late Cambrian. But im not sure how deep in the ground they came from. Either way. I love these rocks and thought I'd share them with you. A lot of the pictures are different angles of the same rock. But theres a few of a second rock. I think i found and cleaned 4 rocks. Just didnt get pictures of all of them. Hope you enjoy. Happy hunting.
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I have been unsuccessful in getting information about this on the general internet (the All-Knowing Google failed me, AGAIN! ). How in the world can you tell if a rock that you have in hand is a stromatolite as opposed to just a rock with striations- like agate or something? Especially if the stromatolite has had a section cut and polished?
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The search for extra-terrestrial fossils is looking more promising. But, I suppose one mustn’t get one’s hopes too high. NASA's Mars 2020 Will Hunt for Microscopic Fossils “Scientists with NASA's Mars 2020 rover have discovered what may be one of the best places to look for signs of ancient life in Jezero Crater, where the rover will land on Feb. 18, 2021. A paper published today in the journal Icarus identifies distinct deposits of minerals called carbonates along the inner rim of Jezero, the site of a lake more than 3.5 billion years ago. On Earth, carbonates help form structures that are hardy enough to survive in fossil form for billions of years, including seashells, coral and some stromatolites — rocks formed on this planet by ancient microbial life along ancient shorelines, where sunlight and water were plentiful. The possibility of stromatolite-like structures existing on Mars is why the concentration of carbonates tracing Jezero's shoreline like a bathtub ring makes the area a prime scientific hunting ground.” “Mars Scientists Investigate Ancient Life in Australia Could Mars ever have supported life? In the Australian Outback, scientists from NASA's upcoming Mars 2020 mission and their counterparts from the joint European-Russian ExoMars mission visited the oldest convincing evidence for life on Earth to prepare for their own searches for signs of ancient life on Mars. The field lesson in astrobiology in the Pilbara region is being applied in the near term by NASA, ESA and Roscosmos for mission planning, and will also pay dividends when both rovers begin to send back science data and imagery from the Red Planet. Credit: NASA/JPL-Caltech Also see: A field guide to finding fossils on Mars. (open access paper)
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Cambrian Stromatolite, looks just like the pics of Sharks Bay
SteveE posted a topic in General Fossil Discussion
Superficially, this beauty looks just like the pics of live ones from Shark's Bay, Australia. Central Pennyslvania, USA
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I had the pleasure of visiting a well known collector in SW Wisconsin a few weeks ago. His home is almost as nice as any museum I have ever visited. He showed us some beautifully crystalized stromatolites that were collected in SE Minnesota. Hints were given as to where to find such specimens. So naturally, I had to find myself an example. I am just not sure if these are just geological and not biological. I hate to question a very knowledgeable man, but obviously I am. Opinions are welcomed. Mike
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I have recently added this piece to my collection. Was sold to me as a Sedimentary Stromatolite from Bolivia. No further info given. I have looked online and in my book and can't match it to anything. Is this a genuine Stromotolite? - it wasn't too expensive, and it's quite attractive either way. Photo of both sides. Roughly 11cm square
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So I seem to have developed an interest in Stromatolites recently. Can someone suggest good / reliable books, websites or pdf papers where I can do further research Thanks
