Clay and sandstone formations tell the geologic history here in Toadstool Geologic Park,Oglala National Grassland,Nebraska. Erosion-resistant Arikaree Sandstone from the Miocene Epoch lies atop Brule Formation Clay from the Oligocene. Underneath it all is the sandy clay of the Eocene Chadron Formation | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Steinberg, James |
Taille de l’image : | 3427 px × 5101 px |
Model Release : | Non requis |
Restrictions : |
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