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Showing results for tags 'lacustrine'.
Found 10 results
Fossil Insects from the Eocene Florissant Fossil Beds (Teller Co, Colorado)
Opabinia Blues posted a topic in General Fossil DiscussionBeing a Colorado native, I have taken multiple trips to the public-access Florissant Fossil Quarry located near Florissant Fossil Beds National Monument in Florissant, Teller County, Colorado. This quarry provides fossil collectors fantastic access to the shale layers of the Florissant Formation, a late Eocene (Priabonian, ~34 million years old give or take) lagerstatte known for its diverse fauna of fossil insects, in addition to plants, gastropods, and very rarely vertebrates. Most fossils occur in very thinly laminated ashy grey shales. Other lithologies present include well-sorted tan cour
Unknown Pleistocene Fossil (Possibly Limpet)
Pseudogygites posted a topic in Fossil IDHi! I’m still trying to identify one fossil from a particular unit of Pleistocene/Early Holocene lacustrine silt from my hometown of Saskatoon, but I figured I would look away from it for a bit to try and identify another fossil from the same unit I’ve been unable to classify. I have two specimens, both apparently of the same species. They are both approximately 0.5 millimetres across. They are perfectly circular, with lines radiating from the centre and rings of alternating colours (possibly representing growth lines). One specimen is photographed dorsally, showing its circular shape, the ot
Miocene Lacustrine Stromatolite
DPS Ammonite posted a fossil in IchnofossilsThis 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 cast
Arizona Miocene Stromatolite
DPS Ammonite posted a topic in General Fossil DiscussionA 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 ins
Arizona Miocene Meanders
DPS Ammonite posted a topic in Fossil Hunting TripsMiocene lakebed deposits north of Phoenix have revealed more than palm and unknown reed like plants. I found stromatolites preserved in black, gray and white chalcedony. Although not as common as in the Precambrian, stromatolites still occur in oceans and in lakes. See article about the ones in Utah’s Great Salt Lake: https://geology.utah.gov/map-pub/survey-notes/glad-you-asked/is-there-coral-in-the-great-salt-lake/ My favorite one is this 10 cm high detail of a much larger stromatolite. #1 This 38 cm one came home with me. #2 Here is a det
Turning Lemons into Limes
DPS Ammonite posted a topic in Fossil Hunting TripsHere are some more Miocene plant fossils from lake sediments north of Phoenix, Arizona. The first large piece of brownish chert, a lemon, had poorly preserved stems. Because the lake sediments had abundant uranium, the rock glowed bright lime green under short wave UV light. Organic matter often attracts uranium deposition.The second piece in the third photo has a great impression of plants that looks like it could have been created in fresh concrete yesterday. Field of view in all photos 6-9cm long.
Badia posted a topic in Fossil IDHi! I always post specimens that may be just minerals... which are the real difficult ones for me to identify. I would like to ask you what do you think about this one. It was found near the other two specimens I posted before, one of them seem to be a baryte nodule and the other one we still do not know for sure. It was found in Santorcaz, NE Madrid province, Spain, in a site where miocene fossils have been found, and where we can still find many limestones which originated in an old lake. I think this may be... only may be... part of an actinocrinites called "calyx" (?). Thank yo
Hello! Is it an echinoid?
Badia posted a topic in Fossil IDHi! This is another specimen I found next to the others I just posted. While the others are red and look like coral, this one looked to me as a skull at first glance. I collected it and I found out it had an intertesting soft texture over the hard stone when I started to clean it. I can say it is a bit like skin... so I stopped the cleaning process because it came off. It seems to be broken. Maybe an echinoid? The problem is always that the fossil may be really inside the matrix... Thanks!
Hello! What is it?
Badia posted a topic in Fossil IDHi, I would like to ask you if you happen to know what these fossils are. They were found in central Spain, on a farm field that I have learned to be a not well-known Miocen limestone lacustrine site. It remineded me of petrified wood when I first saw it and then I thought it could be coral. However, if you look carefully you can see that it was possibly part of a rould-like creature as I could find several pieces that actually fit. As you can see, the creature was not all the same as part of the surface where the pieces seem to assemble look totally different. The surface is not
what is this fossil
Mahogany posted a topic in Fossil IDfound in miocene rocks, lacustrine environment.