The Stratigraphic Units of the Little Badlands
You need to learn the characteristics of the different stratigraphic units before we go into the field. In your field notebooks, make a stratigraphic column showing the different members, formations, groups, and their assigned ages.
|
Groups |
Formations |
Members |
Epochs |
Ma |
|
Coleharbor |
unnamed |
Holocene/Pleistocene |
0-2 |
|
|
Arikaree (Killdeer) |
Miocene |
5-25 |
||
|
White River |
Brule |
Scheffield, Dickinson |
Oligocene |
|
|
White River |
Chadron |
South Heart, Chalky Buttes, (Amidon) |
Eocene |
|
|
Golden Valley |
Camels Butte, Bear Den |
Eocene/Paleocene |
|
(Click on photo for enlarged version). |
Light
yellow, micaceous sandstones (note characteristic piping) and light grey-white
claystones of the Golden Valley Formation capped by the darker grey claystones
of the South Heart Member of the Chadron Formation.
(Photo Allan Ashworth) |
| Cemented
sandstones of the Chalky Buttes Member of the Chadron Formation.
(Photo Allan Ashworth) |
(Click on photo for enlarged version). |
|
(Click on photo for enlarged version). |
What
stratigraphic units are represented in this butte?
(Photo Allan Ashworth) |
| Light brown mudstones of the Brule Formation
(Photo Allan Ashworth) |
(Click on photo for enlarged version). |
|
(Click on photo for enlarged version). |
Fossil
of an oreodont skull from the Brule Formation.
(Photo Allan Ashworth) |
| Popcorn
weathered claystones of the South Heart Member of the Chadron Formation
in the "haystack butte" in the foreground. The South Heart Member
overlies the light grey sandstones and claystones of the Chalky Buttes
Member. What is the yellow colored formation in the background?
(Photo Allan Ashworth) |
(Click on photo for enlarged version). |
