A visit to the Late Carboniferous



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Water Levels

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I thought it would be fun to periodically post water level data, since the sea levels are rising. I'll mostly focus on Lake Michigan, Great Lakes, Atlantic ocean. Here are some pictures of disappearing Juneway Beach in Chicago and a link to an article here . 2019
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A Test on Silurian Corals Stained with Alizarin Red S

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I've been slicing up Silurian corals in order to experiment with some histological carbonate staining techniques and analysis, mostly just to have fun following crystal diagenesis, observe morphological changes through coral life/death, mineralogy, etc.. I still have a lot of learning and work to do. This is just a first test using Alizarin Red S diluted with hydrochloric acid. For photos, I used my old Canon PowerShot SX120IS 10MP. Favosites sp. with Alizarin Red staining. Bridgeport Quarry, Chicago, IL Zoom I need to fix lighting! Above is an unknown specimen found at Hawthorne Quarry, Cicero, IL. It could be Alveolites sp or possibly a Chaetitid sponge. Above is another Favosites slice from the same coral, vertical slice. from Bridgeport showing corallites. Dolomite slice with echinoderm skeletal fragments. From Hawthorne. Zoom Mostly need to figure out a different lighting set up and timing of staining. These were all stained at the sa...
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Opal and Silicified Fossils

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The Paleozoic epicontinental seas consisted of the highest silica concentrations in comparison to the later geologic epochs of the Phanerozoic Eon. Studies show a transition from Cambrian carbonates to predominantly aragonitic marine skeletons beginning in the early Triassic Period as the ocean chemistry and earth's climate changed after the Permian Extinction. In a mutually beneficent relationship, marine organisms use the silica in oceanic waters to build their skeletal shells. Siliceous ooze forms as organisms die and sink to the seafloor. When opal silica accumulates faster than it dissolves, the skeletal fragments are recrystallized and cemented forming chert.  Pictured here is a beautiful fossil coral I found along the Niagara Escarpment near Sturgeon Bay, Wisconsin. The Silurian rocks have resisted glacial meltwaters and erosion as evidenced by the extensive outcroppings, picturesque rocky beaches, and archeological ship wrecks along the peninsula. A first glance an...
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