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Fossils in Tasmania help

Posted: Sat May 16, 2015 11:10 pm
by Philski
HI all

Ive seen a few Tasmanian fossils in the past, on the River Derwent, Maria Island and North West of the state and never thought much about them other than dating the ages of the sedimentary sequence to get a better idea of the past. Today i found a Permian marine sequence West of Queenstown, chock full of bivalves and plants, so know its Permian. The reason its interesting to me, is plenty of exploration companies and geological surveys have explored the area when it was barren easy ground to walk on and only noted the plant fossils so may be a unique find? I have seen the same marine fossils at Black Bluff and further East at Bell creek and both areas have been associated with older alluvial gold trapped in sandstone. So try and compare. This is not in Silurian. The marine fossils i found today are abundant and only occur in a very small strip of land. Dating it is easy, its Permian. 250-290 million years ago, so relativity new. But everything i read in every report says it has to be earlier, Cambrian even, very confusing. I dont have my camera on hand but can show generic photos of them if needed. but they are not as advanced as the Parmeener Super Group fossils and im no marine biologist, but from their size know it was shallow breeding beds. they look like Pippies and barnacles with the odd seaweed thrown in. Its a rich strip of them, chock full of em.. and the only one i have hit here.

just wondering if anyone has any knowledge on Tasmanian fossils, if so, What i just found sub dates our west coast geology by hundreds of millions of years? With specimen in hand, The same colour sequence of the mudstone (misnomer?) is seen in the north scraping on Mount Lyell so know i need to drive further south to hit mineralization. It may not mean much to most but for me to be able to glance 6km or so away is pretty cool prospecting, found with my eyes. no extinct, 250 million year old critter in the greatest extinction rate the earth has ever seen, was harmed the process.

Re: Fossils in Tasmania help

Posted: Sun May 17, 2015 9:03 am
by mfdes
Hey Phil, if there are good plant fossils I know someone who may be interested. He specialises in tertiary flora, but it could be worth a look.

Re: Fossils in Tasmania help

Posted: Sun May 17, 2015 12:37 pm
by Philski
Thanks Miguel,

Its mostly bivalve and brachiopods with a small amount of seaweeds.
i read every report i could find on it and asked a few geos about it and was hoping some one from mineral resources would put me on the right track about it. Anyway,, thank you.
The QVMAG lists a few species in the specimen but they put the limestone surrounding this deposit as Ordovician? Both above and below this level.

Deltopecten limaeformis
Aviculopecten sp. ?
Spirifera strzeleki
Protoretepora ampla

Re: Fossils in Tasmania help

Posted: Sun May 17, 2015 1:24 pm
by Philski
i think i have worked out the strange sequence? The Ordovician deposit today is exposed either side though weathering and this is a depression in it that later filled with the Permian deposit. Hence the small and fossil rich area surrounded by the older rock.

its of no economic importance. So not worth worrying about. thanks

Re: Fossils in Tasmania help

Posted: Wed May 27, 2015 1:22 pm
by Philski
i had a go at extracting one of the fossils (Deltopecten limaeformis) and had pretty good results. It was my first attempt..

These guys do a much better job on trilobites. And was my source of inspiration ... umourensis

Re: Fossils in Tasmania help

Posted: Wed May 27, 2015 4:14 pm
by mfdes
Hey that looks quite good!