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Showing results for tags 'precambrian'.
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Has Anybody Found the Precambrian Fossils in Utah?
DeepTimeIsotopes posted a topic in Questions & Answers
So I've had a hankering for some Precambrian fossils. In Utah, according to this article, there is cyanobacteria fossils present in Utah. Does anybody have any examples of Cyanobacteria fossils that they'd like to show the world so I can have an idea what I'm looking for? If you know anything extra about localities or examples of the Red Pine Shale fossils and don't want to share with everybody we can PM. I'm just trying to get a feel for them before I head out. Thanks. -
I have a small slice of a piece of banded iron from a larger chunk I found in the minnesota river bottoms near minneapolis. The piece is probably a piece of glacial till form the ranges a few hundred miles north but i have not seen any thing so far that is similar to what i have. There is one large band of hematite and magnetite near the center that clearly shows no folds and a smaller less visible band under the lighter orange object also shows no folding. One side of the slice shows a channel or void while the other shows none. If you were to rotate this you would have a cup shape. This structure looks nothing like any stromatolites i have seen and besides the larger band the material seems mostly non compacted. The center of the channel is fairly clear crypto-crystalline material with some yellowish green staining along the inner boundry and clouding along with some black filamentous material (possibly helical) all roughly oriented in the same direction. I put up some videos on you tube and posted on some more mainstream fossil id and geology fourms but have yet to hear anything at all. Not sure if i can link a you tube here but you can find it by looking up banded iron MN new on youtube where i have it under the microscope. I will post a picture but the ones i have are too large to fit so i will try to resize them if there is any interest. Thanks
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https://www.sciencedaily.com/releases/2018/03/180312091407.htm
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Did the First Deep-Ocean Animals Live in a World with Negligible Oxygen?
Oxytropidoceras posted a topic in Fossil News
Did the First Animals Live in a World Without Oxygen? A new study suggests the answer may be yes. https://www.airspacemag.com/daily-planet/did-first-animals-live-world-without-oxygen-1-180967792/ Stolper, D.A. and Keller, C.B., 2018. A record of deep-ocean dissolved O2 from the oxidation state of iron in submarine basalts. Nature, 553, pages 323–327 Received: 10 July 2017, Accepted: 02 November 2017 Published online: 03 January 2018 https://www.nature.com/articles/nature25009 yours, Paul H. -
Until recently classified as a jellyfish, Medusina mawsoni is now considered to be the trace where a holdfast where a rangeomorph such as Rangea was connected to the substrate as in Charniodiscus being the base of Charnia. This specimen is thus about 555 million years old and is from the Rawnsley Quartzite.
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I'm sure you've all seen that banded iron tiger eye stuff from Australia: (pic from Mindat) Does anyone know with confidence anything about it - especially the age and formation name? I find various info online, some of which conflicts. Some say Archean, 2.7by, some say Early Proterozoic... and is it currently accepted as Nimingarra Formation or what? Can anyone find a stratigraphic column showing where this stuff is situated? I can't. I just want the basic info about it, but from a more trustworthy source than the usual websites that get their info from who-knows-where. I know some of you are good at finding literature on sundry subjects. I understand there are two sites in Western Australia that the stuff we find in lapidary shops/etc is likely to be from (see mindat). I don't suppose there's a way to tell which spot the piece you've got came from. If both sites are the same formation I guess it doesn't matter much. And is it stromatolitic, or just sediments containing precipitated iron/iron oxide?
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Replica Fossils from Mistaken Point, Newfoundland?
JUAN EMMANUEL posted a topic in General Fossil Discussion
Hey guys I remember the ROM has on display a slab cast of Mistaken Point, Newfoundland fossils on the Dawn of Life Preview Gallery. Being an admirer of Mistaken Point is there a place where we could perhaps get these replicas? Or are collectors allowed to go to Mistaken Point and take casts of the fossils there for keepsakes? I understand no one is allowed to take fossils there due to government laws so I am hoping that casts are an excellent alternative for amateur collectors. -
Conotubus--An Endearing Ediacaran Critter: My Latest New Favorite Fossil
Virgilian posted a topic in General Fossil Discussion
Conotubus--my new latest favorite fossil. It's an Ediacaran (latest Neoproterozoic--AKA, Precambrian) tubular critter of unestablished zoological affinity (educated guesses include an annelid--specifically some kind of tube worm--or possibly a sea anemone-like animal). And it's been recovered from only two localities on Earth: southern Shaanxi Province, South China; and at one lone site in Nevada. Conotubus shows superficial similarity to the well known Ediacaran tube-type specimen Cloudina, but lacks a mineralized skeleton. Conotubus apparently secreted a tubular home enclosure composed of chitinous material. Image from HERE. Above, two views of the same pyritized (replaced at least partially by pyrite--an iron disulfide, of course, commonly called "fool's gold") Conotubus from the upper Precambrian Esmeralda Member of the upper Precambrian-lower Cambrian Deep Spring Formation, Nevada, where Conotubus occurs several feet below the first appearance of the ichnofossil Trepichnus pedum, which presently helps define (along with geochemical evidence-- a sudden, dramatic negative excursion of a specific carbon isotope) the worldwide base of the Cambrian Period, the transition from Ediacaran times to the earliest moments of the Paleozoic Era. Photograph is a Google Image grab, by the way. Image from HERE. Examples of pyritized Conotubus hemiannulatus from the Ediacaran, late Neoproterozoic Gaojiashan Lagerstätte of southern Shaanxi Province, South China. Photograph is a Google Image grab, by the way. -
I've found fossil imprints in rocks near my cottage south west of Charlottesville, Virginia. The land is eroded, exposing a contact that appears on the Virginia state geologic maps at https://www.dmme.virginia.gov/webmaps/DGMR/ Protererozoic is in light green on the left, Cambrian is in purple on the right. The imprint bearing rocks appear to be from the Proterozic Z meta-argillite sandstone. They were found about 400 feet from the contact. There the land slopes downhill towards the north-west. The rocks were unearthed while digging drainage ditches to protect a neighbor's cottage. Below a few inches of topsoil, the ground is weathered rocks of mixed sizes in a loose powder, all of the of the same uniform redish color. The rocks are easy to break. The strength and appearance is of soft fired pottery clay. The rocks were dumped by a grounds keeper digging the ditches, so I don't know exactly at what depth they were originally. It was less than four feet. The attachment is half an hour's collecting from the diggings dump. If they are of interest, and you are a university based invertebrate paleontologist, I would like to send you your choice at your university address. Perhaps one of your students would like to saw or fracture them. I won't expect any back, but I would like to hear about and see pictures of what is found. All were cleaned under running well water, with a soft hair brush. BTW, I'm an Astrophysics graduate student studying the Andromeda/M31 galaxy using the Green Bank radio telescope. The attached picture is of visiting school children and the telescope, which is about a kilometer beyond the children.
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This could suggest opalised microbial fossils on Mars...
The Amateur Paleontologist posted a topic in Members' News & Diversions
In 1911, near the Egyptian village of El Nakhla El Baharia was recovered a meteorite of martian origin. It belongs to a class of martian meteorites (called "nakhlites") that are derived from a ~1.3 billion year old sill or lava flow. They are mainly composed of magnesium, silica and iron. The Nakhla meteorite showed traces of a very particular form of silica, hydrated and amorphous: opal. This opal was the first in a few traces of martian opal. However, the hydrated silica in the Nakhla meteorite showed showed something rather special: it was very similar to the sort of opal that, on Earth, forms around hydrothermal vents. Around these vents, microbial life thrives and prospers. Could this suggest opalised microbial fossils on Mars? Are we this close to finding fossil life elsewhere in the universe? Further research will tell...- 6 replies
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Hello all, this was sold to me as a chunk of precambrian algae from a reputable dealer. However, I'm having trouble finding photos of anything similar. Is that what it really is, and if so, is there any way to know roughly what kind it is and how old it is? The precambrian era is a pretty big block of time... The largest face of the fossil has bands of hollowed-out "combs" spaced about an inch or so apart. From the other sides, top, and bottom, it's clear that these bands go all the way through the fossil in three dimensions. There are some combs between the banding, but the large number of them in the bands is distinctive.
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I bought this recently in Agadir for only $25 so I'm happy whatever it is. It is said to be a stromatolite, though it may be just a desert rose of some type, though it's very hard and heavy, definitely not gypsum or barite. Some sites on the net suggest precambrian, ranging from 2.6 down to .6 billion years old, depending where you look. Some say Cambrian, some Ordovician and others Devonian or Cretaceous. Any ideas anyone?
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I've seen friends buy these and have been admittedly jealous. Some good ones have come up and I never felt that I could ever afford one. If I waited until I could "afford" one I'd never get one. Soooooooooo, I got myself a Christmas present. Don't ask how much, I won't admit to it. For those that don't recognize what it is, it is a Precambrian Metazoan fossil called Dickinsonia costata. The fossil is over 560 million years old. This one is 9 cm by 13 cm and the best I'll ever be able to get my hands on. Big grin on my face! Love it.
