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Hunt'n 'odonts!

A blog by Acryzona in General

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Dissolving slabs of Ordovician limestone for scolecodonts and conodonts

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3 Acid Baths

Today I started dissolving samples of Rochester Fm (Silurian) from upstate NY, Jacksonburg Limestone (Ordovician) from a quarry near Bethlehem, PA and finally the Whitewater Limestone (Ordovician) from Indiana.
Acryzona

Acryzona

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Buyer Beware! :)

My plan was to allow the limestone to dissolve in the vinegar solution for a couple of days in order to create the buffer solution. Well other things came up (i.e. work) and I didn't look at the solution for a couple of weeks! When I tested the solution, the pH and density indicated that it wasn't diluted to 7%. Something weaker. So I borrowed the family chem set and did a titration to find out what I bought! There wasn't a label on the vinegar I bought but I was told 3 parts water to 1
Acryzona

Acryzona

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Making The Buffer Solution

Before dissolving the limestone slab, a buffer solution needs to be made. The buffer solution moderates the dissolution and keeps the solution pH from starting too low which can damage the microfossils from the slab. After mixing a 7% solution, I added a spare piece of limestone start making the buffer solution. The pH started at 2.5 and had risen to 3.7 about eight hours later. I'm going to keep dissolving the limestone for another day or two and then save this buffer. In the Jeppsson pape
Acryzona

Acryzona

0

Prologue

Last year at a club auction I bought a slab of Ordovician limestone from the Whitewater Formation in Indiana. It is covered in bryzoans and brachiopods. It seems a shame to dissolve it but I've read that the Whitewater contains many species of scolecodonts and the only way to recover them is to dissolve the limestone. This summer's paleo project is to dissolve the limestone with dilute acetic acid. Reading some papers I learned that using HCl can destroy conodonts and even using too strong
Acryzona

Acryzona

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