The Olcott Formation is a geologic formation in Nebraska, United States. It is part of the Ogallala Group and dates to the late Tertiary period (Miocene epoch), specifically the Barstovian North American Land Mammal Age (NALMA). The formation preserves fossils from the Neogene period.
Location and Type Section: The type section is located on the northeast face of "Olcott Hill" in Sioux County, northwestern Nebraska, within the Denver basin geologic province.
Stratigraphy: The Olcott Formation is classified as a formation within the Ogallala Group. It contains several quarries in its type area, including those in the "Sinclair draws" and "Olcott Hill" areas. Quarries in the "Sinclair draws" area are grouped into three depositional subcycles separated by minor erosional hiatuses.
Paleontology: The formation is known for preserving Barstovian-age fossils. Notable fossil taxa recovered from the Olcott Formation include the mustelid (weasel family) species Leptarctus oregonensis, Plionictis ogygia, Plionictis parviloba, "Martes" glareae, and Sthenictis dolichops, as well as the amphicyonid ("bear-dog") genus Amphicyon.
See also:
- List of fossiliferous stratigraphic units in Nebraska
- Paleontology in Nebraska
