Hawthorne Quarry, Part Two

Early one January morning, I returned to Hawthorne. As I descended the hill to the frontage road, a couple of the men from the encampment appeared to be on their way to work. I decided to enter the homeless camp to see if I could find any promising looking rocks on the other side. There was a woman standing under a tarp. It was raining and getting colder. I gave her a few bucks. I didn't really want to bother her. I went about looking for fossiliferous rocks. Cement blocks, bricks and weird conglomerate deceptively weathered appearing as reef material. I didn't find much. Lots of trash, hundreds of malt liquor bottles everywhere. There was even a bed made out of bottles and cardboard. Eventually, I did find this one rock next to a bottle of King Cobra.


I had to pry it out of the mud with a crobar and lug it back to my car. When I got home, I noticed a Calymene impression on the outside of the rock.


When I split it open there was a large Bumastus cephalon inside!


I spent the rest of the day carefully removing the fossil from the rock and gluing the cephalon back together.




An incredible specimen I'm very happy to have found at this lost and "forgotten" locale.



Bumastus (Cybantyx) insignis, Hall 1865 
Date found: January 5, 2019 
Hawthorne Quarry, Chicago (Cicero), Illinois
Niagaran Series, Racine Formation 
Homerian Age (?)
Wenlock Epoch
Silurian Period
Paleozoic Era
Phanerozoic Eon

Measures 5cm across. 
Found in vuggy, porous, bituminous gray reef dolostone with manganese/iron tinged dolomite crystals. Two small clusters of pyrite crystals under left eye. Cephalon found concave side down inside rock near Calymene impression. Other fossils in rock include an unknown coral, possibly a sponge. Left side of cephalon suggests it was transported by currents for a short period before complete burial in reef sediment trap where it was lithified, however could also be due to the carbonate porosity of the dolostone. 




Comments

Post a Comment

Popular posts from this blog

A rare find in the Pennsylvanian Black Shales

Image
On August 17th, I went on a group trip to the Starved Rock Clay Pit. I was specifically looking for some Listracanthus parts, and upon splitting open a large septarion nodule measuring roughly 2ft across, came upon what looked at first like a poorly preserved denticle. Upon returning home and examining more closely, it appeared to have segmentation. After showing photos of the specimen to Dave Carlson and Jack Wittry of ESCONI, it was identified as a rare  Tyrannophontes theridion Shram, 1969. From Wittry's book, The Mazon Ceek Fossil Fauna, "First discovered at Pit 11,  Tyrannophontes theridion was figured and described in 1969 by Shram. Subsequently, similar species were found preserved in the Pennsylvanian black shales of Iowa and Nebraska." Interestingly, nothing is mentioned of the black shales in Illinois. On a side note regarding the mysterious spiny, eel-shaped  Listracanthus that has eluded paleontologists for 150 years ,  a complete specimen has finally b
Read more

Pennsylvanian

Image
Trip to the Pennsylvanian edge of the Illinois Basin. Sunrise 6:30am Stop no. 1 was the Bond formation behind a cemetery near the border of Indiana. The rocks here contain a rich fauna, however I was mostly looking for rugose corals to make thin sections. Stop no. 2 was mostly for scouting for the black Mecca shales to find shark remains.
Read more

Water Levels

Image
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
Read more