Looking for fossils along the river

[Collector9658]

While journeying back out to the Mississippi River, I decided to also stop along the Meramec River in St. Louis. There are exposures of Mississippian aged Warsaw Formation along the river. I passed one, and turned around quickly to try my chances at finding a nice crinoid calyx.

There was a lot of rock exposed, but not much of it was fossiliferous. Much of the rock was caked in mud and thick dirt, which made finding anything difficult.

After a few hours, I did finally manage to find something worthwhile. It was a nice Agaricocrinus crinoid calyx, exposed in the hard bedrock.

Unfortunately, no amount of chipping or pounding was going to get this out of the hard bedrock. Luckily, I had a new grinder in my car I had purchased last week that came with a diamond tipped blade. I had never used a grinder or saw before to extract a fossil from rock, but thought this would be a good opportunity to try and do so. Geared up with my PPE, I used my grinder to put in two relief cuts.

Success! The two cuts made it a breeze to knock out with a hammer and chisel. The crinoid is dirty now, but will clean up nicely when I get time to put towards it.

I packed up my trophy, and decided to drive out to my campsite for the night.

 

The next morning, I took off to a couple of spots along the Mississippi River. There is a lot of rock along the river and in the area, so research is a must! You could wander around a ton of rock and never find a fossil. I had a secret spot mapped out, and today I was not completely disappointed. I had found the Bainbridge Formation rock I was looking for, though unfortunately there was very little rock exposed. A lot of time was spent carefully scouring the few slabs of exposed stone. Here were a few complete, but weathered Calymene trilobites.

Many unsuccessful attempts later, I finally found one I thought that was worth trying to clean up. You can see a small portion of the cephalon exposed.

I gathered a few more non photo worthy trilo-bits for my collection, and packed up my finds. I had a long walk back to my car. Once I got back, my curiosity got the best of me so I spent some time picking away at my last exciting find. I carefully exposed it a little bit, but will stop here for now. I am fairly confident it will be a complete Calymene trilobite! A definite happy end to my weekend off work.

Edited October 20, 2023 by Collector9658

[Tidgy's Dad]

Nice report,

I would like to see the prepping results when you're done, please.

[Collector9658]

5 hours ago, Tidgy's Dad said:

Nice report,

I would like to see the prepping results when you're done, please.

Thank you, and will do. I'll probably send the trilobite to a friend for final cleaning. I'm afraid to damage it from here. 

[Paul1719]

Excellent! I'm always looking for alternatives to expensive gas stone saws. At home I bought a diamond blade for my circular saw that works pretty well but is tied to AC power source. What kind of grinder did you buy? looks like it worked very well.

Cheers,

Paul

[Fossildude19]

3 hours ago, Paul1719 said:

Excellent! I'm always looking for alternatives to expensive gas stone saws. At home I bought a diamond blade for my circular saw that works pretty well but is tied to AC power source. What kind of grinder did you buy? looks like it worked very well.

Cheers,

Paul

 

 

Paul,

I have one of these.  It works quite well, with a diamond blade.

The only drawback is the 4.5 inch blade, which will only cut about 2 inches if your rock is completely level.

I use it to trim down blocks, and to cut fossils out of larger blocks.

Does well enough for my purposes, though.

 

[Paul1719]

Hey Tim, Thanks! very reasonable. How deep will it cut? Not 2"? I could also use for blacksmithing! Love to stack functions!!

[Collector9658]

9 hours ago, Paul1719 said:

Excellent! I'm always looking for alternatives to expensive gas stone saws. At home I bought a diamond blade for my circular saw that works pretty well but is tied to AC power source. What kind of grinder did you buy? looks like it worked very well.

Cheers,

Paul

The link Tim attached is very similar to the angle grinder I purchased and used. This is the specific model and one I had in this post

https://www.dewalt.com/product/dcg415b/20v-max-xr-4-12-5-brushless-cordless-small-angle-grinder-power-detect-tool-technology-tool-only

I got it because It's cordless. I run a 20 volt, 8 AH battery that seems to run pretty smoothly. Easily cuts into hard limestones with a diamond blade. Great to extract a small specimen or trim a block Like Tim stated. It only cuts around 2 inches deep into rock, but it works very well for the purposes I intended it for.

 

-Jay

Edited October 29, 2023 by Collector9658