Jump to content
Tiesta

Myths of fossiling Twin Cities

Recommended Posts

Tiesta

I found plenty of myths onlines, books, media. One recent Star Tribune article on landscape rocks called Platteville limestone from ancient lake. Not true at all! Actually it is mostly dolomite with small amounts of limestone and shale mixed in.

 

Minnesota DNR website under fossil list says that shark teeth are found all over the Twin Cities and sounds like its common as heck. Actually its not true. Glaciers would had grounded them to dust. I think the myth comes from the fact that they occurs in central Minnesota (buried very deep under soil) or most likely from western Minnesota via the Minnesota River. So its possible to find them from Minnesota River Valley through where it meets the Mississippi River. Sounds easy? Not really.... most of the Minnesota River Valley of the Twin Cities are mostly inaccessible except from boat. And even then, the low flow rate of the Minnesota River would likely bury any shark teeth that washed downriver as beds of pebbles are hard to find. Several sources report that both the Mississippi River and Minnesota River deposits more sediments on the valley floor than wash them out. In fact the best odds for finding shark teeth are if theres a big flood going down the Minnesota River that covered the entire floodplain, washing plant debris, etc off and carve new cuts through the valley floor that exposes layers of deposited river rocks.

 

Lastly Ordovician fossils - a myth is that they are well study in the Twin Cities - no they are not. Many fossils that I finds don't have specimen names just genus since they are poorly researched and new rare ones show up all the time that I suspect are new undescribed species. I feel that the vast majority of professions in the fossil field are mainly focused on the Cretaceous fossil beds in the Iron Range. They didn't really impress me that much, being mostly cast fossils and heavily stained in iron so its harder to see any fine details as they are dark as heck.  

Share this post


Link to post
Share on other sites
FossilDAWG

I suspect you are thinking of modern-looking shark teeth, along the lines of sand tigers or great whites.  Such teeth would indeed be non-existent in the Twin Cities area.  However Paleozoic shark teeth can be found.  These do not look much like modern sharks, and I doubt that they are abundant or even very common, but they are there if you know what to look for.

 

Don

Share this post


Link to post
Share on other sites
Raggedy Man
1 hour ago, Tiesta said:

I found plenty of myths onlines, books, media. One recent Star Tribune article on landscape rocks called Platteville limestone from ancient lake. Not true at all! Actually it is mostly dolomite with small amounts of limestone and shale mixed in.

  The Platteville limestone is a term I hear when going into home and garden centers in Grant County, WI. The description you gave matches the Platteville here in WI. The Platteville "limestone" is actually dolomitic limestone. In Wisconsin, the Platteville consists of alternating 1-4 inch thick bands of dolomitic limestone with thin shale layers separating each band. 

Share this post


Link to post
Share on other sites
3cats

Cretaceous shark teeth can be found in western Minnesota.  Many years ago, I spent some time screening sand on the shores of Lake Shetek, looking for anything of interest.  Among the things I found were two small shark teeth, about a half inch in size.  From what I could find out, they are probably from the Cretaceous Coleraine and Windrow formation which crops out in various places near there, especially near Springfield.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Recently Browsing   0 members

    No registered users viewing this page.

×