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Showing results for tags 'stromatolite'.
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I was gifted a rock specimen from the estate of a professional geologist. I was immediately attracted to it as a tall, columnar structure very coral like. It has been cleanly sawn at the base and it layered, laminae structure immediately indicated stromatolite. It is about 15 inches tall and 5.5 inches at the base; it weighs about 7 pounds. At first I thought it was a fossil but these three things stand out contrary to that. First, it has air voids in it; it is not completely mineralized through. Second, the external layer is cleanly exposed. If it was a fossil, the surrounding matrix must have been highly erodible as the fine detail of the outside layer (visible exterior) is remarkable. Third, consistent with #1 and #2 the "rock" has not been metamorphosed. We have fossil stromatolites here in Minnesota and they are embedded structure in Mary Ellen Jasper, which is a beautiful rock. Unfortunately, I have no idea where this came from. The dad of my friend who gave it to me lived in South Dakota and was in the Pacific Theatre in WWII, but was not known to be much of a traveler otherwise. Based on my 3 reasons above, I think this may be a specimen of a modern, extant stromatolite that somehow ended up with the geologist. I know there are living modern stromatolites with columnar structure at Pavilion Lake BC, and at Lago los Centas in Porvenir, Tierra del Fuego, Chile. Certainly there are fossil examples of columns too in the record. Really just looking to see if anyone on this forum has seen anything like this before? It is beautiful in its own way. Thanks in advance. Bill J.
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I have recently discovered my interest in rock hounding. From my small/moderate amount of research, I am guessing that this is Stromatolite. I found it in a yard bordering a graveyard in Maquoketa, IA. I would love to know a little more about it,. It weighs right around 4 lbs. At the one end, it appears that some form of fossil had burrowed in.
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Hi! Just wanted to know if this is Oncolite? In sandstone? Also, what are the bits protruding from the rock? Found it in Southern Texas nearby the Mexico border. Thanks!
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From the album: Fossil Collection: DC Area and Beyond
Inzeria tjomusi Bashkortostan, Russia Katavskaya Formation Tonian -
Approx. 90mm dia x 15mm thick Long time lurker. First time poster. Thanks for having me! Hoping for info on this specimen. I have spent about 10 hours over the last 6 months trying to positively ID and I am stumped. I found this specimen and accompanying materials after a one hour 4Lo rock crawl followed by a grueling two hour uphill hike near Horseshoe Lake, Maricopa County, Arizona. Thank goodness for traction boards or I would have been walking back to the main road! I was out for chert, chalcedony, and other fossil material when I came across this laying right on the surface. Stupidly, I should have grabbed a picture right then. In my excitement, I failed to. From the description of the surrounding area (copied below) I believe it to be some form of a Stromatolite. However, the other photos I found online don’t seem to match up very well. For one, this thing is pure black something. I cannot find an example of one this color. Also, this specimen has a “slice” that runs from approx. its center to almost its outer edge and is through the piece (visible in photo). Which makes it look much more organic in form than other Stromatolites I see. Other ones appear very “geologic” looking to me. My rockhound partners who are not deeply knowledgeable in fossils have said it reminds them of a mushroom or some type of sea anemone. That’s the type of organic matter form that it resembles anyway. As a long time hound myself, I am struggling to determine the composition. It’s not like coal and doesn’t resemble any material I have previously seen or collected. It’s really best described as “graphite like”. The smaller pieces pictured have also given me few clues. They leave a brownish black streak on white paper. I cracked a small piece of the end of one and in the sun the material really sparkles like glitter and is a bit sandpaper-ish. On the outer surface the material is smooth feeling otherwise. Other guesses are some type of larger Tufa or a Coprolite of some sort (but what sort). I am definitely all ears and thank you in advance for taking your time to look. Info on the surrounding areas and why I believe it may be some type of Stromatolite: "That's not snow! This is Chalk Mountain adjacent to the Horseshoe Reservoir on the Verde River. According to Wrucke and Conway (1987, USGS OFR- ), Chalk Mountain consists of white to light-gray, finely laminated limestone. Chert also occurs but is minor. Small centimeter-scale stromatolite-like mounds suggest an origin as algal mats growing on a paleo-lake bed. The authors suggest the deposit may be correlative with the Plio-Miocene Verde Formation." For the report and map: LINK
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I have what look to be bones, they have agates where tissue would have been.
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This was found in Ponte Vedra, Florida on the beach. The measurements are in inches. I think it is really interesting even if it’s not a stromatolite. I love my beach treasures. I appreciate any input. Thank you in advance!
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So I went to see a client of mine this morning in a town I haven’t been to before There was a crystal shop which I popped in to They had this piece of banded iron formation (approx 5cm across). But she didn’t know where it was collected from. Anyone have any idea ? @MarcoSr, @Wrangellian ???
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From the album: Permian fossils from Rheinland-Pfalz, sw-Germany
a rare, 30 cm wide stromatolite from a closed site in Rheinland-Pfalz-Region. Permian age, showing fantastic internal structures -
Need some help on these maybe fossils quarried from Blackberry hill, Wisconsin
SilurianSalamander posted a topic in Fossil ID
Found in the side of a building and in the surrounding landscaping. From the Cambrian seashore sandstone of Blackberry Hill Wisconsin. The place is known for its fossils of mass jellyfish strandings and its trace fossils of some of the first arthropods, mollusks, and other animals on land. What are these? Thanks!
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- 500 million years ago
- blackberry hill
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I've been working on an apparently novel concept with planted terrariums incorporating diorama features to recreate ancient environments. This setup in a 65-gallon glass enclosure is the best developed so far. It combines plants more or less representative of a Late Cretaceous Sequoia Redwood forest with a proposed Hesperonychus elizabethae replica nest with eggs. This dromaeosaurid is known from a few fossils in the Dinosaur Park Formation of Southern Alberta and is apparently the smallest known non-avian dinosaur from North America.
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Stromatolites are potentially present in every geologic period. Show any if you got 'em. The goal here is to represent every period, and every stage/epoch if possible, including subdivisions/periods of the Precambrian. These can be posted in no particular order. Any and all are welcome to post multiple examples from any period/epoch. I'll start with a specimen from the Pennsylvanian: Sniabar Limestone, Kasimovian/Missourian Stage, Pennsylvanian Kansas City, Missouri, USA The front side has been polished.
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Need help confirming what I found. This speciman was found in Milwaukee, WI. I found it in some loose landscape rock around the building I work in. Unfortunately I don't have a ruler on me right now but it's about 2 inches long and 3/4 inches wide. Originally I thought it was agate but someone in my rock group on Facebook says it looks to be silicified stromatoporoid. After doing a Google search I came across stromatolites also. So I'm not sure which one it could be. It's a beautiful specimen. What looks to be quartz on the bottom and what I originally thought was agate surrounding it. Any ideas of what this could be? Thanks a ton! (Sorry about holding the speciman. These pics were taken when I found it and I have the specimen at home and not on me right now. I tried to crop out my fingers) Pics: side view, end view and top view
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Hi! Is this a stromatolite? I picked up this rock on the premises of the Teleajen oil refinery in Prahova county, Romania. I have seen a chert wedge in a limestone boulder once upon a time, but this stone is different. It has layers of chert and carbonate, right? I grinded and polished the stone. Here is a close-up from the carbonatic area (fizzles with acid): Any idea how old are these rocks when found in S-E Europe? Thanks!
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Hello i found this pebble in a Jurrasic area in Oman . The waves on the beach smoothened it. I found numerous coral and bivalve and Gastropod fossils. im thinking this may be a stromatolite? could it be? thank you very much for your time!
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Hardly anybody ever talks about the Cambrian fossils of the southern midcontinent (USA). They're super-underappreciated. Show us what you've got! Here's one to start us off: Thorax and pygidium of a trilobite, possibly Orygmaspis, typically referred to as "Orygmaspis cf. Orygmaspis llanoensis" but probably a different species altogether. Note the two pairs of macropleural spines marking the final thoracic segments. Davis Formation (late Cambrian: Furongian), south side of Highway 8, St. François County, Missouri.
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An End-of-Year Fossil Hunt with Stromatolites Galore
Elasmohunter posted a topic in Fossil Hunting Trips
What better way to celebrate the end of the year than with a little fossil hunting? And the hunt ended with some spectacular stromatolites; read on! ----- When I got an itch to hit the field last month, I reached out to a quarry in Perrysburg, Ohio to collect fossil and mineralogical samples for donation to academic institutions. The quarry was kind enough to grant me permission to collect on their property for several hours in late December, so when the time came, I suited up and headed out with a trusty assistant. The quarry exposed outcrops of the Lockport and Greenfield Dolomites separated by a thin lens of shale. We were permitted to collect from the outsides of the berm piles surrounding the walls, but I wasn't sure what to expect, as dolomites often exhibit poor fossil preservation, and I had never hunted these units before. Even so, we eagerly hit the berm piles with rock hammers in hand. The quarry wall. The Greenfield Dolomite (red line) sits on top of the Lockport Dolomite (blue arrow), which extends to much deeper than the shelf upon which the photo was taken. The shale horizon between them can be clearly seen as a dark line. Almost immediately, I found a small brachiopod, but then it was several more minutes before we found other fossils. We proceeded to find a variety of reef-building organisms. A small brachiopod (1) and . . . the underside of a Favositid coral (2)? A friend suggested that the larger of these two fossils (3) is a Favositid coral. I'm not sure about the smaller one (4); maybe a bryozoan? This find (5) confused me: it looked like a concretion, seemed to be covered in iron oxide, and had an odd, striped/fluted pattern inside. A friend suggested that it could be slickenslides. It was the only rock that I saw that looked anything like this, and it really stood out against the dolomite. The best finds of the day, however, were undoubtedly the stromatolites. The quarry exhibited them in abundance, and they were readily found throughout the berm piles. The rounded tops of a group of stromatolites. The mottled top of a stromatolite. More layers can be seen just above the left side of the rock hammer. Check out this stromatolite (6)! The coin on it is an American penny. It came from a stromatolite that seemed to be at least 60 or 70 cm in diameter. Not only did we find fossils, however; we also found several crystals, as the dolomites were scattered throughout with crystal-containing vugs. Here's the largest crystal that we found. I haven't tested it with acid, but I suspect that it's calcite. We collected a few other crystals too and even saw some purple ones hiding in a seam in a large boulder. Unfortunately, someone beat me in discovering stromatolites here by many decades, so I didn't make an groundbreaking discoveries, but the trip was nevertheless a wonderful way to round out the year, and all of these samples will end up in academic institutions. May you all have even better fossil hunts in the new year! Cheers, Elasmohunter
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While vacationing in northern Minnesota, I picked up this piece of Mary Ellen Jasper. My goal was to have one side polished in order to bring out the features of the stromatolite. Unfortunately, my attempts to find someone locally to polish it failed. Does anyone have knowledge of someone who could tackle this for me?
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A chunk of stromatolite i brought home and two I left behind.
Raistlin posted a topic in General Fossil Discussion
Some day I'll bring the two home. But I don't feel like carrying them out one at a time.
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Since the spring my wife and I have been very busy with the garden and the orchard to maintain, the canned vegetables from our production, and we decided last Thursday to take a break for a geological excursion south of Clermont-Ferrand. The goal was twofold, to search for stromatolites and to take advantage of the volcanic context of the region. The detailed geological map of this area is unavailable but we had serious research ideas for our prospecting. The day began with a visit to a magnificent village that immediately immersed us in the context: Saint Saturnin. The walls of houses often combine basalt and limestone from the surrounding area. Usually tourists look at the fountain or the castle from a distance, but some are more original ... So, let's look at some examples in the walls of the houses in the village.
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I posted pictures of this uncut stone/fossil several weeks ago hoping for an ID, but since I didn't know the location it was found, the consensus was it most likely is stromatolite. I've had it cut and polished and it's gorgeous! It's very dark inside. The circular parts look like they are gray and black, but in real life it seems to be just 2 different textures of black. The parts that look more gray are rougher/grainier and the blacker areas are more smooth and reflective/shiny. The circular parts almost look like fluffy clouds. The in between area is dark gray until you get near the edges where it is more brown/mud color, with a few small spaces of white quartzy looking stone dotted throughout. Pics are from outdoors and indoors. Do you still think it's stromatolite? and does the inside give any more clues to possible location or age? Thank you for your time and your comments
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Hi, I bought this at a flea market in McKinney, TX about 8 years ago and am trying to get it identified. The person selling it didn’t have any information on where it was found or what it is. I took it to a local rock shop recently to see if it could be ID’d. The owner is more skilled in minerals, but he thought it might be a fossil (stromatolite), and recommended I reach out to someone skilled in fossils to know for sure. Magnets do not stick to it at all. I found a small seashell attached to it, but nothing else on the outside. It’s a rounded triangular shape. Measures about 8 1/2” (32cm) tall and the base is about 7” wide by 6” deep. It weighs just a little over 16 lbs. The material in-between the fossils(?) can be scraped away pretty easily, like a sandstone. Any knowledge shared is sincerely appreciated! !
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Not sure what to make of this, came from mix of Cretaceous and QAL, breaks very easily. Thinking it's sedimentary but then wouldn't it be harder?
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I have seen this for sale online Seller got it from an old collection and has no provenance info. He has no idea where it was collected or formation info is this some sort of geological formation ? Or is it a genuine 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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