Vanguard Formation

{{Infobox rockunit

| name = Vanguard Formation

| image =

| imagesize =

| caption =

| type = Geological formation

| age = {{Fossil range|Callovian|Oxfordian|Callovian to Oxfordian}}

| period = Oxfordian

| prilithology = Shale, sandstone

| otherlithology =

| namedfor = Vanguard, Saskatchewan

| namedby = Milner & Thomas

| year_ts = 1954

| region = WCSB, Williston Basin

| country = Canada, United States

| coordinates = {{coord|49.36|-107.79|display=inline,title|name= Vanguard Formation}}

| unitof =

| subunits = Masefield Shale
Roseray Formation
Rush Lake Shale

| underlies = Mannville Group

| overlies = Shaunavon Formation

| thickness = up to {{convert|180|m|ft|-1}}

| extent =

| area =

| map = {{Location map+ | Canada

| relief = 1

| width = 300

| float = center

| places =

{{Location map~ | Canada

| lat_deg = 49.36

| lon_deg = -107.79

| mark = Blue pog.svg

| marksize = 12

}}

}}

| map_caption =

}}

The Vanguard Formation is a stratigraphical unit of Callovian to Oxfordian age in the Western Canadian Sedimentary Basin.

It takes the name from Vanguard, and was first defined by R.L. Milner and G.E. Thomas in 1954.Milner, R.L. and Thomas, G E., 1954. Jurassic System in Saskatchewan. In: Western Canada Sedimentary Basin. American Association of Petroleum Geologists, p. 250-267