Help identifying locations of Mississippian era formations in Northern Illinois

[Joseph Fossil]

I've recently been trying to locate some new fossil sites (particularly those of Mississippian age) to go to and I found some places that might seem interesting. I found them looking at a slightly old geologic map of Illinois and I was wondering if anyone can tell me where exactly these locations are and if they are particularly fossil rich?

 

 

https://www.mindat.org/loc-14607.html

[Joseph Fossil]

The first location I'm a bit curious about is a stretch of Mississippian rocks in LaSalle County, IL.

 

[Joseph Fossil]

The second location (or more accurately locations due to its size) is a large area on the Illinois-Indiana border with large sections of Mississippian rocks.

 

 

[connorp]

You've had a lot of very specific questions about locations. I think you would do well to learn how to do this research yourself. It is an invaluable skill to have.

[Oxytropidoceras]

You can start by looking at the geological maps in the USGS Geologic Map Viewer.

For example, there is the Bedrock Geology of Illinois. This small patch of Ordovician

is centered around Grand Ridge, Illinois. Unfortunately it is covered by glacial deposits.

 

For topographic maps, go to the USGS Topographic Map Viewer.

 

Also, go look at Illinois State Geological Survey publications.

 

Yours,

 

Paul H.

Edited December 30, 2022 by Oxytropidoceras
rewording text

[Joseph Fossil]

On 12/30/2022 at 2:02 PM, Oxytropidoceras said:

You can start by looking at the geological maps in the USGS Geologic Map Viewer.

For example, there is the Bedrock Geology of Illinois. This small patch of Ordovician

is centered around Grand Ridge, Illinois. Unfortunately it is covered by glacial deposits.

 

For topographic maps, go to the USGS Topographic Map Viewer.

 

Also, go look at Illinois State Geological Survey publications.

 

Yours,

 

Paul H.

 

@Oxytropidoceras Thanks dude! The Bedrock geology map of Illinois you sent is actually really good! It shows the closest Mississippian bedrocks to Chicago are around Bishop, Mason County, Illinois and around Cissna Park, Iroquois County, Illinois. Do you know of any scientific papers describing the prehistoric fauna of Mason County and Iroquois county, Illinois?