NEOPROTEROZOIC / CRYOGENIAN:
ORGANIC OR INORGANIC?
I got these pictures from Michael Szwabo. These structures were found near Kunanarra in Western Australia. Michael wrote: "They are from the Ranford formation in W.A., and they are 670 m.y. old. Some people think these are evaporites or gypsum crystals, others think they're jellyfish or some sort of metazoan." - What do YOU think?
Mineralogist say they are not minerals or evaporites. It is West Aust Museum that calls them evaporites. Kath Grey has only examined a couple of hand size specimens in the Geoscience collection and never visited the
site, based on early datings of 2 billion years.
Ranford formation has since be re dated to a more recent date. Tha deposit sits above the Zebra stone deposits which are also microbialites large Medusa have been found in the deposit as well as other larger organic strictures in area.
In this case, I can only work from the photos here, in a few of them it looks as though the structures cross cut sedimentary features and post-compactional lamina, usually a sure sign of a diagenetic origin.
Have you checked out the episode of palaeocast that is all about fossil jellyfish etc? If not it's well worth a listen and might help you understand what you are seeing in these rocks.
And they are in the process of studying with material along with zebra stone
Mineralogists have varieties that.
Also they are not aware of any other mineral with that habit
Bruce Stinchcomb Some of these specimens appear to be folded as though they were originally composed of a material which was flexible (like an organic material). If they were crystals such as selenite or some other inorganic mineral, they would not do this.
Michael Szwabo One when is the things that Bruce Stinchcomb noticed was that many of these structures un are are rolled over or Lipped. If these were crystals they would break it would require a leathery kind of Skin or dermis for them to roll up and over and that was a pretty convincing argument to me .indeed ifthey were Crystal and they would break and shatter.
Sandra Nəusər Meine Tochter sagte eben: Mama, die sehn aus wie vertrocknete Quallen auf Steinen am Strand, hab ich mit Oma und Opa in Spanien gesehn! Ich widerspreche ihr nicht ;)