Sunday, March 24, 2013

Screening the Silica Shale for microfossils

My next experiment with my new screen set was with a sample of eroded Silica Shale that I'd collected from an old dump bank near Sylvania, Ohio. Since the Silica Shale is contemporaneous with the Arkona formation I should find similar fossils. I had a little bit of a harder time with this sample as I think I loaded more raw material than I should have into the screens. It took me much longer to wash out the clay and I was having to filter out plant debris but in the end I had my results.

The first screen I look at is the #35 as that is where I expect to find most of the microfossils. I did find some Ostracods as well as quite a lot of broken fossils. This is likely because the sample I washed was of previously weathered material.



But it was not long before I started finding Ostracod fossils.





This last pic I think has a Quasillites sp, Ostracod in the middle left.

Onto the #60 screen and it yeilded much of the same, albeit smaller pieces. I also noticed sand grains which is not typical for the Silica shale but is to be expected in a mixed weathered environment.






The last two screens showed nothing of interest but quartz and pyrite mineral grains. I may start to ignore these when sifting. It will depend on if I can spot anything with a real microscope as opposed to my Zorb microscope camera (which is not a microscope, just a camera capturing the view through a magnifier in a case with some focus tools).


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