Drakes fm. vs Kope fm.

[Fullux]

Howdy all,

 

This is something I've wondered for a while.

 

What is the relationship between the Drakes and Kope formation and what are the differences?

[Tidgy's Dad]

It's all a bit complicated.

But the Kope Formation outcrops in Ohio, Kentucky and Indiana and is Edenian in age, near the base of the Cincinnatian, roughly 450 mya.

The Drakes Formation is at the top of the Richmondian at the top of the Cincinnatian and outcrops in Kentucky. Maybe 445'6 mya.

In Kentucky, the Fairview, Grant Lake, Waynesville, Bullfork and Whitewater Formations all occur between the Kope and Drakes.

 

[Fullux]

9 minutes ago, Tidgy's Dad said:

It's all a bit complicated.

But the Kope Formation outcrops in Ohio, Kentucky and Indiana and is Edenian in age, near the base of the Cincinnatian, roughly 450 mya.

The Drakes Formation is at the top of the Richmondian at the top of the Cincinnatian and outcrops in Kentucky. Maybe 445'6 mya.

In Kentucky, the Fairview, Grant Lake, Waynesville, Bullfork and Whitewater Formations all occur between the Kope and Drakes.

 

So the only real difference is age?

 

I was thinking that it was because they were in different parts of Kentucky or the types of rocks foudn there.

 

I suppose it makes sense.

[Tidgy's Dad]

15 minutes ago, Fullux said:

So the only real difference is age?

 

I was thinking that it was because they were in different parts of Kentucky or the types of rocks foudn there.

 

I suppose it makes sense.

No, there are differences in the rock types, the fossils found there and different parts of Kentucky sometimes use other names.

Another more recent Cincinnatian system has, from youngest to oldest, the Drakes Fm. Upper Whitewater Fm. Saluda Fm. Lower Whitewater Fm. Liberty Fm. Waynesville Fm. Arhneim Fm. Grant Lake Fm. Miamitown Shale, Fairview Fm. Kope Fm. Claysferry Fm.

Different parts of Kentucky have different formations exposed at the surface.

Edited October 19, 2023 by Tidgy's Dad

[FossilNerd]

@Tidgy's Dad has you steered down the right path.

 

I’d just like to add the below. A word of caution or helpful hint since it sounds like you are researching the lithostratigraphy of Kentucky.
 

Geological formations are sometimes frustrating and confusing. They can be named something totally different in older literature, or even reassigned from formation status to member status. Similar to how fossils can get renamed and reclassified over the years.
 

The same rock layers in one state can also be named something different in another, or even classified as a formation in one state, and a member of a formation in another.  
 

States have their own geological survey departments and it is up to them to name and classify the geology there, or recognize an already named formation as being exposed. They don’t always agree.