Possible Cretaceous Flint(?) fossils at new site, shells.

[Irongiant97]

So I went to a new site nearby me where I heard there were shark teeth and  while I didn't find any shark teeth I found flint(?) fossils, that, unlike my previous flint(?) fossils, which I believe were deposited by glaciers, I think these ones are native to where I found them, which is an old mine overburden pile (the rock above the ore they're mining for), my evidence for this was the presence of many iron rich rocks that was in the same pile, pictured I have what I believe is botryoidal hematite, which hematite is what they mine here. Also the fossils in these new specimens are different to my glacial ones, which mostly have crinoid stems and brachiopods, here I've got spiral shells and other clams. Also they're much bigger and in much better shape. The Coleraine formation (cretaceous) runs just south of where I live according to a bedrock map, and another nearby mine tapped into it years ago (Hill Annex) and is fossil ferric, the bed rock map shows it doesn't quite reach the mine I live next to, but I'm doubting the map is perfectly accurate since the mine I live next to has dug up sharks teeth, fish vertebra, and saw fish saw teeth. (MN Discovery Center has some on display).

 

Anyway, any help identifying these and what possible time period? I really hope they're native fossils and not glacial.

 

 

Edited April 2, 2022 by Irongiant97

[Lone Hunter]

From the outside the rock looks like chert to me, I can't make out anything except last 3 pictures, the spiral is a gastropod, not sure about the bivalve but someone should know that and maybe age.

[Fossildude19]

I agree this is chert, and likely paleozoic, rather than mesozoic.

 

There doesn't appear to be any Cretaceous sedimentary rock in Itasca County:

 

[Irongiant97]

5 minutes ago, Fossildude19 said:

I agree this is chert, and likely paleozoic, rather than mesozoic.

 

 

Where I live, flint and chert is interchangeable. Also weird, all the maps I read say this area is either Cretaceous or well before the Pre Cambrian period (Minnesota weird like that), almost everything inbetween is missing in our geo record. Could these and the shark teeth be glaciel, too?

Edited April 2, 2022 by Irongiant97

[Irongiant97]

1 hour ago, Fossildude19 said:

There doesn't appear to be any Cretaceous sedimentary rock in Itasca County:

 

Look up the "Coleraine Formation"

here's a PDF of a better map.Geologic_Map_of_Minnesota-_Bedrock_Geology_(2011).pdf

And a pic pointing out where I live, sandwhiched between the mesaba iron formation and the Coleraine Formation.

Edited April 2, 2022 by Irongiant97

[Fossildude19]

Have you looked at these pdfs?

 

 

Unfortunately, any time glaciers are involved, that leaves a lot up to speculation. 

The papers/websites I have been looking at all mention limestone, shale, and sandstone as the fossiliferous components of the Cretaceous formations.

The second paper listed by piranha says this:

 

 

 

While your items could be Cretaceous in age, I would tend to think any chert cobbles would be of older derivation.

[Irongiant97]

5 hours ago, Fossildude19 said:

Have you looked at these pdfs?

 

 

Unfortunately, any time glaciers are involved, that leaves a lot up to speculation. 

The papers/websites I have been looking at all mention limestone, shale, and sandstone as the fossiliferous components of the Cretaceous formations.

The second paper listed by piranha says this:

 

 

 

While your items could be Cretaceous in age, I would tend to think any chert cobbles would be of older derivation.

Thanks, this'll be really helpful! Yeah, I've been coming to the conclusion that glaciers muck up things, finding these new fossils among iron ore leads me to believe they may be native since similar finds have been found at Hill Annex, which the fosssils there are native, and is only 12 miles away from me.