American geologic scale

[fifbrindacier]

Hi, i recently saw the Missourian and Pennsylvanian age, but i cannot find to what period they correspond, could enlight me please ?

[Troodon]

Does this answer your question?

 

timescl-1.pdf

[Fossildude19]

[doushantuo]

I have posted on the Carboniferous timescale before,with radiometric ages and all

Section correlation remains difficult,and detrital zircon ages keep coming in, as well.

There is still a dearth of complete, undisturbed sections that will allow intercontinental and /or terrestrial/marine correlation.

Cantabrian,anyone?

[Fossildude19]

2 minutes ago, doushantuo said:

I have commented on the Carboniferous timescale before,with radiometric ages and all

 

Link us up, Ben!  

[doushantuo]

 

[doushantuo]

some advances have been made in untangling the effects of (among other parameters) paleoclimate and eustacy in e.g. the Appalachian basin,as well as structural geological apects

(edit:Black Warrior Basin,if i remember correctly)

With sequence-stratigraphic implications,of course

[fifbrindacier]

1 hour ago, Troodon said:

Does this answer your question?

 

timescl-1.pdf

Yes, and thanks to all of you. Most of the time i find out the equivalence, but not this time.

[doushantuo]

the Missourian is part Stephanian "B"(the Autunian auctorum)

And approximately the Doromilgovskian in the Russian basin(Krevianinsky horizon in the Moscovian basin and  the Urals)

That means chronostratigraphically,it is Kasimovian(part of the Parashumardites goniatite zone)

This must have clarified things for a lot of people

[Wrangellian]

Seems few members yet know of my timescales here on TFF:

 

Granted, the forum is getting pretty big and it may be hard to find..

Now why does a simple link turn into a big box with the beginning of the thread above the line where I intended the link to be?

Scroll down a little more than 1/2 way on P. 2 to get to the North American version which correlates the International version.

 

 

 

[piranha]

Here is an excellent Carboniferous correlation from:

 

Gradstein, F.M., Ogg, J.G., & Schmitz, M. eds. (2012)
The Geologic Time Scale 2012, 2-volume set.
Elsevier Scientific Publishing, 1176 pp.

 

 

 

 

[Ridgehiker]

Re the above and 'North American'.  Canada has much more Carboniferous exposure than the USA and we never use those terms.  Mississippian and Pennsylvanian is largely an eastern USA terminology with some limited use elsewhere in the 

USA.  The 'type' exposures in Nevada use 'Carboniferous' terms.  This is an extention of western European/ Canadian/ Russian stratigraphy.

 

Any Americsn researchers we worked with have always used 'Carboniferous' terms (either European or Russian based).

 

 

[fifbrindacier]

14 hours ago, doushantuo said:

the Missourian is part Stephanian "B"(the Autunian auctorum)

And approximately the Doromilgovskian in the Russian basin(Krevianinsky horizon in the Moscovian basin and  the Urals)

That means chronostratigraphically,it is Kasimovian(part of the Parashumardites goniatite zone)

This must have clarified things for a lot of people

Da, tovaritch.

[Missourian]

In the American Midcontinent, at least, the Mississippian and Pennsylvanian are very different from each other lithologically and paleontologically. Additionally, they are separated by a major unconformity.

[Ridgehiker]

2 hours ago, Missourian said:

In the American Midcontinent, at least, the Mississippian and Pennsylvanian are very different from each other lithologically and paleontologically. Additionally, they are separated by a major unconformity.

 

Good point above.

 

One needs to remember that the age divisions are 'tools' used for stratigraphy. They are not based on some universal geology. For the most part they were established in Europe  and bit of later tweaking.  If ages were determined by the geology of South America or eastern Asia, etc.age divisions would be quite different.  The Mississippian/Pennsylvanian unconformity mentioned above in thr eastern USA  doesnt exist in the type locale of the Carboniferous in Nevada.

 

We have actual formations spanning the Mesozoic/Cenozoic division in North America with no break between the Cretaceous and Palaeocene.  There are also formations in the Rockies that span the Devonian/Carboniferous boundary. 

 

When we do stratigraphic studies the ages are  an agreed upon length like a meter stick or time in an hour.  They make sense historically but could be some other type of agreed upon measurement. 

 

 

[DPS Ammonite]

19 hours ago, Canadawest said:

Mississippian and Pennsylvanian is largely an eastern USA terminology with some limited use elsewhere in the 

USA.

I am familiar with and have collected in the rocks from Texas to California. I almost always use "Mississippian and Pennsylvanian" instead of Carboniferous. Most published papers on the geology in those states also use "Mississippian and Pennsylvanian". In deference to the rest of the world, most researchers do point out that the Mississippian and Pennsylvanian are part of the Carboniferous. There is limited use of "Mississippian and Pennsylvanian" in California and the Pacific Northwest because of the scarcity of rocks not because most people use the term Carboniferous instead.

 

Hopefully we will continue to use "Mississippian and Pennsylvanian" since most rocks in the US are already divided into and named by those terms. The lumpers in the rest of the world should be allowed to use Carboniferous if they desire. 

 

Creating a uniform geologic timescale is helpful even if some minor regional differences exist. 

 

[Wrangellian]

The ICS uses 'Mississippian' and 'Pennsylvanian' for Early and Late Carb. I don't mind using either, I think everyone knows what they all mean and I'm not sure why there's a debate. The only people I can see having a problem with Miss and Penn is the Europeans, where the boundary seems to cut right thru the Chokierian in the Namurian.

[TNCollector]

The Mississippian and Pennsylvanian are like day and night here in Tennessee. In general, the Mississippian is almost exclusively marine and the Pennsylvanian is almost exclusively terrestrial. This makes the fossils and rock type drastically different.

[tmaier]

All these names are somewhat oxymoronic because they are local. The Devonian period refers to the goelogy of Devon, England. And so forth, these names describe things that do not apply globally. It is just tradition to use them. The major period names are well known, and the minor divisions are less known, and I try to avoid using them.

I usually avoid Miss. and Penn., and just say upper and lower Carboniferous. It's easier to spell and just makes more sense.

I read a lot of old literature, and these period names were not standardized in the 18th and 19th century, so you see a lot of weird divisions in old books. In many books they refer to "antediluvian period" and "postdiluvian period", meaning before and after Noah's flood. =) Each authr sort of made up their own time period names.

But they are standardized in the 20th century...

https://en.wikipedia.org/wiki/Geologic_period