Elko Formation

{{Infobox rockunit

| name = Elko Formation

| image =

| caption =

| type = Formation

| age = Mid Eocene (Uintan)-Mid Miocene
~{{fossil range|46.2|11.6}}

| period = Oligocene

| prilithology = Shale

| otherlithology = Limestone

| namedfor = Elko County

| namedby =

| region = Nevada

| country = {{USA}}

| coordinates = {{coord|40.8|N|115.8|W|display=inline,title}}

| paleocoordinates = {{coord|41.5|N|112.9|W|display=inline}}

| unitof =

| subunits = Elko Shale

| underlies =

| overlies =

| thickness =

| extent =

| area =

| map = {{Location map+ | United States#Nevada

| relief = 1

| width = 250

| float = center

| places =

{{Location map~ | United States#Nevada

| lat_deg = 40.8

| lon_deg = -115.7

| mark = Orange pog.svg

| marksize = 8

}}

{{Location map~ | United States#Nevada

| lat_deg = 41.1

| lon_deg = -115.5

| mark = Orange ff8040 pog.svg

| marksize = 8

}}

{{Location map~ | United States#Nevada

| lat_deg = 40.8

| lon_deg = -115.8

| mark = Yellow pog.svg

| marksize = 8

}}

}}

| map_caption =

}}

File:Metasequoia occidentalis USNM P36883 img3.jpg
Elko Formation]]

The Elko Formation, also known as Elko Shale(s), is an oil shale geologic formation in Elko County, northern Nevada, United States. The deltaic and lacustrine shales and limestones preserve fossils dating back to the Middle Eocene of the Paleogene to Middle Miocene of the Neogene period. The frog genus Elkobatrachus and ant species Pseudocamponotus elkoanus were named after the formation.