Alberta
Higher resolution map -
During the Mesozoic, before the Rocky Mountains arose, a vast depression developed in the mid-continent of North America. It apparently extended from the Gulf of Mexico to the Arctic and from roughly the line of the current Mississippi River on the East to Arizona, Utah, Idaho, and Alberta on the West. Initially, the depression collected lowland sediments, but as time passed, it deepened and marine waters flooded in forming a shallow sea. The mid-continent sea apparently waxed and waned, but toward the end of the Cretaceous, the sea began to shrink as the land started to rise and the sea filled with sediments. The last remnants of the interior seaway are found in Paleocene age deposits of North Dakota and the prairie provinces.
The rocks associated with the mid continent sea are widely exposed in the prairies of Canada and the US as well as in the Rocky Mountains of the US and in the Eastern Great Basin and Colorado Plateau. In the East, they are deposited unconformally on late Paleozoic marine and lowland beds. Further West they are deposited on more heterogeneous rocks including deposits of Triassic and Jurassic continental and marine rocks. Typically, the inland sea beds consist of cyclic deposits of coal and sediment grading into shallow marine deposits of sandstone, shale and limestone that deepen. Later, the process is reversed with shallow water deposits and cyclic coal and sediment. In the Western part of the region, sometimes thick Tertiary deposits cap the inland sea deposits. In the East there is a hiatus followed by mid-Tertiary deposits composed of material eroded from the Rocky Mountains. Further East, deposits become more scattered and there seems to have been little or no subsequent sedimentation.
The deposits are continuous into the Gulf of Mexico Terrane in the SouthEast. I have chosen to place the arbitrary separation between the two regions in Texas roughly along the line of Interstate 20.
I have (somewhat arbitrarily) included some early Mesozoic beds in these rocks even though there can be substantial hiatus between beds in these sequences and there is a long gap between the Jurassic Morrison formation and the more or less continuously deposited beds of the interior seaway.
Missing Formations: Fossils:
Interior Seaway beds are well exposed in the Canadian Rockies and in river valleys in the Canadian plains. The lithology is primarily thick repeated cycles of mostly sandstone accumulation. Numerous local formation names and problems in correlating which sandstone cycle is exposed where exposures are separated by long distances have made the nomenclature somewhat confused. see Western Canadian Sedimentary Basin
| Age | Formation | |
|---|---|---|
| Upper Tertiary beds (mostly volcanics)... | ||
| Tertiary | Rubio Peak - Timberlake | |
| Eocene | Lobo | |
| Cretaceous,Upper | Salero | |
| Cretaceous,Upper | Fort Crittenden | |
| Cretaceous,Upper | Fort Buchanan | |
| Cretaceous,Lower | Turney Ranch | |
| Cretaceous,Lower | Cintura - Shellenberger Canyon - Hay Flat | |
| Cretaceous,Lower | Mural - Apache Canyon - Santa Rosa| | |
| Cretaceous,Lower | Morita - Lowell - Willow Canyon - Cowboy Spring - Ringbone Formation - Little Hat Top Formation | |
| Cretaceous,Lower | U-Bar | Mojado - Broken Jug |
| Cretaceous,Lower | Glance - Hell To Finish |
| Mesozoic intrusives, Paleozoic beds, PreCambrian beds |
up to 1660 meters of varicolored Upper Cretaceous clays and coal found in the Green River basin and Uintah uplift of Wyoming,and Utah. Plant fossils.
up to 200 meters of Upper Cretaceous sandstone,shale,clay and coal found in the Green River basin of Wyoming,and Colorado. Some brackish water invertebrate fossils
Up to 430 meters of Permian(?) and Triassic continental red shale with minor sandstone and limestone with minor limestone found in the Green River and Snake River basins, Uinta and Wasatch uplifts and Yellowstone province of Idaho, Utah, and Wyoming. Petrified wood and bark occasionally present.
As much as 250 meters of Lower Cretaceous clay and sandstone found in the Fort Worth syncline,South Oklahoma folded belt,Ouachita folded belt,and Permian basin of New Mexico,Oklahoma,and Texas. Overlies older formations unconformally.
Up to 600 meters of Lower Cretaceous limestone,sandstone, and siltstone found in Arizona(se). It overlies the Willow Canyon Formation and is overlain by the Shellenberger Canyon Formation. It is thought to be contemporaneous with the marine Mural Limestone. It is a member of the Bisbee Group
Fossils: A few plants and vertebrates (dinosaur bone fragments)
A Cretaceous sandstone found in Saskatchewan and Manitoba. Contains some dinosaur fossils
up to 660 meters of dark Upper Cretaceous marine shales with abundant fish scales found in the Green River basin and Uintah uplift of Wyoming,Idaho,and Utah.
In excess of 300 meters of Eocene Clay,Tuff,Shale,Sandstone, and Conglomerates exposed in the Wind River Basin of Wyoming. vertebrate fossils.
An Upper Cretaceous sandstone exposed in the Yellowstone region of Northwest Wyoming.
Up to 8 meters of abundantly fossiliferous red weathering sandstone exposed on Peace River in Northern Alberta with ammonites and bivalves.
Up to 146 meters of Triassic limestone, dolostone, siltstone and sandstone in Northern British Columbia and Alberta Rocky Mountain foothills. Considered to be part of the Schooler Creek Group.
Up to 14 meters of dark shale with a few fragmentary fossils found in SouthEast Alberta and Southwest Saskatchewan.
Up to 1200 meters of fossiliferous marine Uppermost Cretaceous shale and sandstone found in the Green River basin of Wyoming. Considered to be the lowest formation in the Montana Group.
Up to 350 meters of marine shales and mudstones with minor sandstones, bentonites, etc. found in Southern Alberta,Southeast Saskatchewan as well as the Powder River basin,Central Montana uplift,Williston basin,Big Horn basin, Montana folded belt province, and Sweetgrass arch of Montana and Wyoming. Fossils include well preserved ammonites, many other invertebrates and numerous marine vertebrates. To the South and East it is equivalent to the Pierre Shale.
Fossils: Marine invertebrates -- ammonites,other invertebrates, marine vertebrates, a few dinosaurs.
Coals and sandstones with fresh and brackish water fossils. Generally regarded as Lower Cretaceous. Found in the Green River basin,Snake River basin, and Wasatch uplift of Idaho,Utah and Wyoming
In excess of 3000 meters of Paleocene sediments in the folded belt province of Montana and the Snake River Basic of Idaho. Consists of two thick conglomerate formations sandwiching limestone and heterogeneous deposits in the middle member. Dated from fresh water gastropods
Up to 560 meters of Lower Cretaceous lacustrine shale and conglomerate found Green River basin,Snake River basin,and Wasatch uplift provinces of Idaho and Wyoming. Some fresh water invertebrate fossils.
Up to 300 meters of occasionally fossiliferous marine Cretaceous shale and bentonite with a medial limestone bed found in Central Montana uplift,Montana folded belt province,Chadron arch,Williston basin,Powder River basin,Wind River basin,Green River basin,Sweetgrass arch regions of Montana, North Dakota, South Dakota, and Wyoming.
Up to 1300 meters of mudstone and fine grained sandstone with minor sandstone, shale bentonite, and coal found across Southern Alberta and Saskatchewan. The name is used interchangeably with the probably preferable term Judith River Formation in the plains area.
Unknown -- apparently a Cretaceous(?) shale formation overlying the Viking Formation in Southern Alberta and Saskatchewan and the Flotten Lake Sandstone in the Central Plains.
More than 1000 meters of heterogeneous Upper Jurassic(?) and Lower Cretaceous found in Arizona(se) and New Mexico(sw). The Bisbee overlies Paleozoic beds/Mesozoic Volcanics and is overlain by the Faraway Ranch Formation/Gila Conglomerate/Little Hat Top
Fossils: Marine invertebrates in some of the limestones
Up to 427 meters of dark grey to black mudstone and siltstone with minor limestone, sandstone, and bentonite found in the Rocky Mountain foothills of Alberta South of the Athabaska River. Yields cephalopods and pelecypods.
Up to 700 meters of Upper Cretaceous sand and shale found in the Green River basin of Wyoming. Contains marine fossils. Originally assigned to the Montana Group but modern usage puts it in the Mesaverde Group.
Up to 2000 meters of Lower Cretaceous sandstones and pebble conglomerates found in the Rocky Mountains and Foothills in Southwest Alberta and adjacent British Columbia.
Up to 700 meters of marine Cretaceous sand and shale found in the Montana folded belt province and Sweetgrass arch of Northwest Montana where it is at the base of the Colorado Group. Fossils include bivalves and fish vertebrae.
Up to 30 meters of light colored sandstone with abundant Ophiomorpha burrows found in a narrow North-South band in SouthWest Alberta.
An Upper Jurassic wind deposited sandstone found in the Paradox and Black Rock Mesa basins of Arizona and Utah where it is overlain by the Morrison Formation
Up to 64 meters of unfossiliferous probably Triassic limestone found in the Rock Mountain foothills of NorthEast British Columbia. It is considered by some to be the uppermost formation in the Schooler Creek Group
100 meters of Tertiary redbeds and volcanic tuff found in Arizona(se). It overlies the Bisbee Group and is overlain by the Faraway Ranch Formation
Fossils: None
Up to 175 meters of Lower Cretaceous sandstone, siltstone and mudstone found mostly subsurface in the plains of Alberta, Saskatchewan and Montana.
Up to 950 meters of non-marine sandstone with minor coal, shale, and bentonite in the Northern and Central Rocky Mountain foothills. Spans the Cretaceous-Paleocene boundary
Eocene sandstone found in the Green River basin of Colorado, Utah, and Wyoming. Vertebrate fossils.
A probably obsolete term for 1525 meters of Lower Cretaceous limestone,shale,sandstone,and conglomerate found in New Mexico(sw). It overlies the Mojado Formation? and is overlain by the Ringbone Shale. It is a member of the Bisbee Group
Fossils: Marine invertebrates in the upper beds.
Lower Oligocene clay,volcanic ash, and sand exposed in the Wind River, Denver, and Williston basins as well as the Sioux uplift and Chadron Arch of Colorado, Montana, North Dakota,Nebraska,South Dakota and Wyoming.
Up to 1000 meters of dark fossiliferous marine Cretaceous siltstone and fine grained sandstone found on the fringes of the Rocky Mountain foothills in Northern British Columbia.
Up to 900 meters fluvial of non-marine conglomerate ad sandstone with minor coal, shale, and bentonite in the Northern and Central Rocky Mountain foothills. Some plants and dinosaur trackways.
Up to 170 meters of Lower Cretaceous silicon cemented conglomerate with minor siltstone and sandstone and a little coal. Found in the Rocky Mountain foothills of Alberta and British Columbia.
Up to 100 meters of fossiliferous Paleocene marine shale and sandstone found in the Williston Basin of North Dakota. This is the youngest marine unit in the inland sea deposits in the US.
Up to 120 meters of Lower Cretaceous mudstone and sandstone found in the Williston Basin area of Saskatchewan. Middle part of the Mannville Group
Up to 108 meters of fossiliferous marine sandstones separated by non-marine shales. Found along essentially the full length of the Canadian Rocky foothills from near the US border to Dawson Creek, BC
Up to 200 meters of fossiliferous Upper Cretaceous marine shale and limestone. Widely distributed along the Rocky Mountain front and the plains East to Iowa and Minnesota. It is part of the Colorado Group.
Up to 200 meters of fossiliferous marine middle Jurassic sandstone with shale gypsum and limestone. Found in the Black Mesa basin,Great Basin province,Green River basin,Paradox basin,Plateau sedimentary province,San Juan basin,Uinta basin, and Uinta uplift of Arizona, Colorado,New Mexico,Utah,and Wyoming. It occupies the interval between the Navajo and Entrada sandstones. Marine fossils are found in the limestones.
10 to 20 meters or more of latest Eocene and Earliest Oligocene clay and gravel exposed in narrow bands in the Wind River, Denver, and Williston basins as well as the Sioux uplift and Chadron Arch of Colorado, Montana, North Dakota,Nebraska,South Dakota and Wyoming. Vertebrate fossils. It is exposed in the Bighorn and Wind River Basins as well as the Yellowstone region of Wyoming.
Up to 405 meters of Triassic calcareous Sandstone, siltstone, limestone, anhydrite in the Rocky Mountain foothills of Northern British Columbia and Alberta. It is part of the Schooler Creek Group.
Up to 43 meters of Lower Cretaceous friable sandstone found in the Anadarko basin,Sedgwick basin, and Central Kansas uplift of Kansas where it is the lowest part of the Purgatoire Group and lies between the upper parts of the Purgatoire and Triassic redbeds. Contains wood fragments and Cycad fossils
Up to 400 meters of Permian and Triassic shales, limestones, and gypsum found in the Big Horn,Denver,Powder River,Green River,and Wind River Basins and the Yellowstone province of Colorado, Montana, and Wyoming. Fossils reported.
Up to 400 meters of Upper Triassic shales with minor limestones,sandstones,conglomerates,and gypsum found in the Black Mesa basin,Great Basin province,Green River basin,Las Vegas-Raton basin,Orogrande basin,Palo Duro basin,Paradox basin,Permian basin,Piceance basin,Plateau sedimentary province,San Juan basin,Sierra Grande uplift,Uinta basin,Uinta uplift, and Wasatch uplift of Arizona,Colorado,Nevada,New Mexico,Texas and Utah. Is treated as a subdivision of the Dockum Group in Texas. Fossils include petrified wood, plant fossils, and vertebrates
600 meters of Lower Cretaceous Shale, limestone, and Sandstone found in Arizona(se) and New Mexico(sw). It overlies the Mural Limestone and is overlain by recent deposits. It is a member of the Bisbee Group
Fossils: A few marine invertebrates.
130 meters of Upper Cretaceous marine shale and sandstone found in the Powder River basin and Central Montana uplift of Montana and adjacent Wyoming. Fossils are found in some beds.
up to 130 meters of Lower Cretaceous continental sandstones and clays found in the Powder River and Big Horn basins of Colorado,Montana,Utah,and Wyoming where it rests unconformally on Jurassic beds
Up to 550 meters of Uppermost Cretaceous (and Paleocene?) sandstone, shale, mudstone, siltstone, coal, bentonite, and conglomerate found in the Rocky Mountain foothills along the North Saskatchewan and Athabaska Rivers.
Up to 800 meters of Upper Cretaceous marine and continental (?) shale and sandstone found in the Montana folded belt province,Central Montana uplift,Big Horn basin,Powder River basin, and Wind River basin of Montana,Wyoming, and possibly Idaho. It is apparently the lateral equivalent of several better known and better differentiated formations such as the Niobrara Limestone that are found to the South and East.
Up to 1500 meters of Cretaceous shales and limestones with minor inclusions of other rock types found across Southern Alberta and Saskatchewan and Southward through the US midcontinent exposures except possibly in Arizona. In Canada is mostly known from subsurface coring Members include the Medicine Hat Sandstone,Martin,Cardium Sandstone,Bowdoin Sandstone,and Phillips Sandstone. In the US it includes the Coberly,Dunkleberg,Frontier,Graneros,Greenhorn,Marias River,Mowry,Niobrara,Thermopolis,and Warm Creek Formations.
In excess of 30 meters of fossiliferous Lower Cretaceous marine limestone found in the Permian basin,Strawn basin,Bend arch,Ouachita folded belt,Llano uplift* of Texas where it occupies the interval between the sands of the Antlers/Walnut formations and the Edwards Limestone. Abundant fossils reported in the lower part of the formation.
Oligocene volcanic rocks clay found in Beaverhead County, MT. May have been reassigned to the Sage Creek Group.
An obsolete term for 1220 meters of Lower Cretaceous Mojado Formation found in New Mexico(sw). The beds are part of the Bisbee Group
Fossils: Marine invertebrates?
At least 300 meters of Lower Cretaceous limestone cobbles,sandstone,shale, and tuff found in New Mexico(sw). It overlies the Mojado Formation/U Bar Formation and is overlain by the Timberlake Fanglomerate
Fossils: None?
Up to 1670 meters of Eocene floodplain deposits conglomerate, shale, clay and sandstone found in the Las Vegas-Raton basin of New Mexico.
Up to 85 meters of marine mid Jurassic sandstone shale and conglomerate found in the Green River basin,Paradox basin,Plateau sedimentary province,Snake River basin,Uinta uplift,Wasatch uplift,Yellowstone province of Colorado, Idaho, Utah, and Wyoming. Overlies the Entrada formation and is overlain by the Summerville formation. Fossils resemble those of the Sundance formation.
Up to 80 meters of Oligocene sand and gravel with a few conglomerates or marls exposed in scattered plateaus in Southern Saskatchewan and Alberta.
60 to 100 meters of Lower Cretaceous continental sandstone with minor beds of other sorts in places found in all US portions of the midcontinent sea region except Idaho. Fossils include leaves and wood. In many places, the Dakota is the lowest Cretaceous formation
Up to 230 meters of Lower Triassic calcareous shales and sandstones grading laterally into gypferous redbed sandstones and shales found in the Montana folded belt province,Yellowstone province,Big Horn,Green River,Wind River basins, and the uplift of Idaho,Montana,Utah,and Wyoming. Contains obscure mollusk fossils
Up to 130 meters of Middle and Upper Triassic conglomerate,sandstone,shale and clay found in the Permian basin,Las Vegas-Raton basin,Palo Duro basin,Sierra Grande uplift and Anadarko basin of Colorado,Kansas,New Mexico,Oklahoma and Texas. Petrified wood is commonly found and vertebrate fossils are reported. Generally lies on Permian formations.
Up to 364 meters of grey Triassic siltstone and shale with phosphate nodules near the base found in NorthEast British Columbia, NorthWest Alberta and the Southern Yukon Territory.
Up to 100 meters of Cretaceous lacustrine algal limestone found Green River basin,Snake River basin,Wasatch uplift,and Yellowstone provinces of Idaho and Wyoming. Some fresh water invertebrate fossils.
Up to 300 meters of late Cretaceous sandstone and shale exposed in the Northern Rocky mountain foothills and plains. It is marine in the East grading to continental in the West.
Up to 90 meters of late Cretaceous continental sandstone, greenish shale, conglomerate and occasionally lignite found in the Powder River basin,Central Montana uplift,Montana folded belt province,and Sweetgrass arch regions of Montana and Wyoming. Contains plant fossils and fresh water mollusks.
Up to 30 meters of late Cretaceous sandstone, greenish shale, conglomerate and occasionally lignite found in Southwest Saskatchewan and SouthEast Alberta. There are a few poorly preserved marine invertebrates in the lower portions.
As much as 150 meters of fossiliferous Lower Cretaceous marine limestone found in the Permian basin,Strawn basin,Kerr basin,Ouachita folded belt,Gulf Coast basin, and Llano uplift of Texas.
As much as 2000 meters of Upper Cretaceous volcanics tuffs,breccias,and conglomerates found in the folded belt province of West Central Montana. Fossils rare or absent.
Up to 150 meters of Jurassic shale and sandstones in the plains of Southern Alberta and Northern Montana. It is divided into the Swift, Rierdon, and Sawtooth Formations
Up to 500 meters (but usually much thinner) of mid to late Jurassic sandstone found in the Anadarko basin,Black Mesa basin,Denver basin,Great Basin province,Green River basin,Las Vegas-Raton basin,Paradox basin,Piceance basin,Plateau sedimentary province,San Juan basin and Sierra Grande uplift of Arizona,Colorado,New Mexico,Utah and Wyoming.
Up to 330 meters of Cretaceous(?) conglomerate found Green River basin,Snake River basin,and Wasatch uplift provinces of Idaho and Wyoming. It is the basal member of the Gannett group
200 to 300 meters of unfossiliferous Upper Cretaceous sandstone found in the Green River basin of Wyoming, Utah, and Colorado. It is a member of the Mesaverde Group.
Up to 500 meters of Eocene(?) sandstone and coal in the Green River Basin,Wasatch uplift,and Uinta uplift of Idaho,Utah, and Wyoming.
Lower Cretaceous sandstones found in the Chadron arch,Powder River basin, and Williston basin of Montana,North Dakota,Nebraska,South Dakota and Wyoming.
250 meters of Tertiary volcanics found in Arizona(se) where it overlies the Bonita Park Formation/Bisbee Group and is overlain by the Rhyolite Canyon Formation
Fossils: None
Up to 400 meters of dark Jurassic marine shales with minor limestones, siltstones and sandstones exposed in the Canadian Rockies and Westernmost plains of British Columbia and Alberta. Numerous members and formations have been identified within the beds. Some Geologists believe that it should be treated as a group rather than a formation. Marine invertebrate fossils are reported from some beds.
Up to 2000 meters of non-marine Late Cretaceous and possibly Early Paleocene sandstone,siltstone,shale and coal found in the Green River Basin of Wyoming
Up to 21 meters of Lower Cretaceous sandstone overlying the Viking Formation in East Central Alberta and West Central Saskatchewan. Exposed in the valley of the Saskatchewan River.
Up to 140 meters of fresh and brackish water Upper Cretaceous sandstone,shale,shell beds, and coal found in Southern Alberta and adjacent Saskatchewan. Dinosaur remains are fairly common and mollusks are abundant in some layers. It is the lowest formation in the Judith River Group
600 meters of sandstone and shale above a basal conglomerate. It overlies an unnamed lava/Bisbee Group and is overlain by the Fort Crittenden Formation
Fossils: None?
700 meters or more of Upper Cretaceous conglomerate, sandstone and shale found in Arizona(se). It overlies the Fort Buchanan Formation/Bisbee Group and is overlain by the Salero Formation It is a member of the Sonoita Group.
Fossils: Dinosaurs, fish, other vertebrates
Up to 2200 meters of fossiliferous Latest Cretaceous and Early Paleocene sandstone shale, limestone and coal (but usually much thinner) found in Powder River basin,Williston basin,Uinta basin,Piceance basin,Central Montana uplift,Green River basin,Big Horn basin,and Wind River basin of Colorado,Montana,North Dakota,South Dakota and Wyoming
Up to 160 meters of fossiliferous Late Cretaceous marine sandstone and clay found in Denver basin,Green River basin,Powder River basin,Williston basin of Colorado,Montana,North Dakota,South Dakota and Wyoming
Up to 2000 meters (mostly subsurface?) of dark Cretaceous shale with sandstone, conglomerate and bentonite. It is found in NorthEast British Columbia, Northern Alberta, the Yukon and the Northwest Territories. There are numerous subgroupings into the following formations: Cruiser Formation, Goodrich Formation, Hasler Formation, Gates Formation, Moosebar Formation, Shaftesbury Formation, Peace River Formation, Spirit River Formation, Sully Formation, Sikanni Formation, Lepine Formation, Scatter Formation, Garbutt Formation, Buckinghorse Formation
Up to 113 meters of latest Cretaceous non-marine sandstone and claystone found in Saskatchewan and SouthEast Alberta
Up to 2600 meters of fossiliferous Cretaceous marine shale and sandstone with some coal beds near the top in some areas found in Big Horn basin,Central Montana uplift,Green River basin,Montana folded belt province,Piceance basin, Powder River basin,Snake River basin,Uinta basin,Uinta uplift,Wasatch uplift.Wind River basin,Yellowstone province of Montana,Wyoming,Colorado,Idaho,and Utah. It is part of the Colorado Group.
Up to 170 meters of Upper Cretaceous coastal swamp shale,sandstone,and coal found in the Paradox basin,San Juan basin,and San Juan Mountains province of Colorado and New Mexico. Occupies interval between the Pictured Cliffs and Kirtland formations. Diverse vertebrate fossils.
Up to 30 meters of Early Cretaceous continental shale and sandstone found in the Chadron arch,Powder River basin,and Williston basin of Montana,North Dakota,Nebraska,South Dakota and Wyoming.
Up to 1000 meters of Cretaceous continental/lacustrine sediments found Green River basin,Snake River basin,and Wasatch uplift provinces of Idaho and Wyoming. It consists of the Ephraim conglomerate, the Draney Limestone, the Bechler Formation, the Peterson limestone and the Tygee(Smoot) Sandstone.
Up to 290 meters of occasionally fossiliferous Lowest Cretaceous sandstone and siltstone in NorthEast British Columbia.
200 meters of Upper Tertiary terrestrial sediments interbedded with volcanics found in Arizona(se) and New Mexico(sw). It overlies the Bisbee Group and is overlain by unnamed Quaternary beds. The Gila is divided by some authors into San Manuel, Quiburis and Sacaton Formations
Fossils: pockets of vertebrate remains in the Quiburis beds.
Up to 1200 meters of Upper Jurassic and Lower Cretaceous conglomerate found in Arizona(se) and New Mexico(sw) It overlies Mesozoic intrusives, Precambrian intrusives or Paleozoic limestones/Concha Limestone. It is overlain by the Willow Canyon Formation/Morita Limestone It is the lowest member of the Bisbee Group
Up to 60 meters of Jurassic limestones, shales and sandstones found in Southern Alberta, Saskatchewan and Manitoba as well as adjacent Montana. Marine fossils are found. Abundant fish scales are found in the basal beds
As much as 300 meters of fossiliferous Upper Cretaceous marine dark shale and sandstone widely distributed from the Rocky Mountains East to Iowa and Minnesota. Found in all parts of the region except Arizona,Idaho,and Utah above the Dakota Sandstone and below the Greenhorn Limestone.
Up to 100 meters of fossiliferous Upper Cretaceous Limestone widely distributed from the Rocky Mountains East to Iowa and Minnesota.
Up to several hundred meters of lacustrine Eocene shales and oil shales found in the Green River, Piceance, and Uinta basins in Colorado, Wyoming and Utah as well as in exposures along the Wasatch front in Utah. Noted for its well preserved fish and plant fossils, but other vertebrates, insects, bird tracks, etc are found in some beds.
Up to 90 meters of Middle Jurassic gypsum, sandstone, shale and limestone found in the Green River,Uinta,Wind River,Powder River and Snake River basins, Wasatch uplift and Yellowstone province of Idaho, Montana, South Dakota, Utah, and Wyoming.
Up to 416 meters of Triassic sandstones with minor other rock types found in Northern British Columbia and Alberta. Marine fossils are found. It is the oldest formation in the Schooler Creek Group.
Up to 2000 meters of non-marine Paleocene and Early Eocene river delta mudstone,sandstone,conglomerate and coal found in the Hanna Basin of Wyoming. Fossils reported
Up to 1600 meters of non-marine Uppermost Cretaceous sandstone,siltstone,shale and conglomerate found in the Green River basin and the adjacent Yellowstone region. Abundant plant and fresh water mollusk fossils.
600 meters(?) of Lower Cretaceous limestone found in Arizona(se). It is a member of the Bisbee Group. It overlies the Mural Limestone and is overlain by Tertiary sediments. It is probably an (unnecessary) alternate name for the Cintura Limestone
Fossils: Unknown-Probably at least a few marine invertebrates
Up to 70 meters of mostly non-marine Uppermost Cretaceous and Early Paleocene. sandstone,and clay found in the Williston basin, Central Montana uplift, and Powder River basin of Montana and North and South Dakota. Abundant vertebrate and invertebrate fossils.
Up to 2000 meters of Lower Cretaceous shales and mudstones with minor limestones found in New Mexico(sw). It overlies the Concha Limestone [WCPALEO.HTM#Concha]/Earp Formation and is overlain by the U-Bar Limestone. It is a member of the Bisbee Group
Fossils: Abundant bivalves in the upper beds
Up to 2200 meters of marine Uppermost Cretaceous shale with minor limestone found in the Green River basin of Wyoming and Utah. Contains ammonites and bivalves.
Up to 1600 meters of non-marine Paleocene(?) sandstone, and shale with some limestone found in the Green River Basin and adjacent Yellowstone region of Wyoming. Fossils include some fresh water mollusks and possibly some vertebrates.
400 meters of Upper Cretaceous sandstone,clay,and coal found in Idaho(e). It overlies the Bacon Ridge Formation
Fossils: Marine mollusks in one bed
Up to 230 meters of latest Cretaceous floodplain and estuarine mudstone shale and sandstone with minor coal and other rocks. It is Found in west central Alberta. It yields fairly abundant dinosaur remains as well as other fossils.
Up to 100 meters Upper Cretaceous brackish water and marine sandstone found in the Sweetgrass arch and folded belt province of Montana. Fossils include brackish water and near shore marine mollusks.
Up to 1500 meters of Eocene floodplain conglomerate,sandstone,shale,clay, and marl found in the Las Vegas-Raton basin of Colorado and possibly adjacent New Mexico.
Roughly 300 meters of early Eocene clay and conglomerate found in Wyoming's Wind River Valley. Abundant vertebrate fossils.
Up to 60 meters of early Cretaceous shale, mudstone, and sandstone found in the Southern Plains and central plains of Alberta and Saskatchewan.
Up to 360 meters of late Cretaceous siltstone, mudstone, sandstone, bentonite and coal found in the Southern Plains of Alberta and Saskatchewan as well as the Sweetgrass arch,Central Montana uplift,and Williston basin of Montana,North Dakota,and Wyoming It yields fairly abundant dinosaur remains as well as other vertebrates and invertebrates.
Up to 900 meters of fossiliferous late Cretaceous marine dark grey shale with some sandstone interbeds in NorthEastern British Colombia and adjacent Alberta. Contains bivalves, cephalopods and foraminifers
Up to 215 meters of non-marine Late Triassic and/or Early Jurassic sandstone with a few thin fossiliferous limestone beds found in the Paradox basin,Plateau sedimentary province,Black Mesa basin,San Juan basin and Great Basin province of Arizona,Colorado,Nevada,and Utah. Fossils consist mostly of fresh water gastropods and reptile trackways. Occupies the interval between the Wingate and Navajo Sandstones.
Up to 30 meters of Lower Cretaceous shale found in the Anadarko basin of Colorado, Kansas, Oklahoma, and possibly New Mexico. Is the uppermost member of the Purgatoire Group
Up to 594 meters of Upper Cretaceous and/or Paleocene non-marine shale found in the San Juan basin of Colorado and New Mexico. Occupies interval between the Fruitland and McDermott formations. Diverse and vertebrate fossils.
Up to 230 meters of fossiliferous Oligocene(?) lakebed deposits found in the vicinity of Kishenehn Creek, BC and adjacent Montana.
Up to 1335 meters of continental Late Jurassic and Early Cretaceous sandstone, shale and coals found in the Southern Rocky Mountains of Alberta,British Columbia and Montana. Sometimes referred to as a formation, modern usage is to regard it as a group including Morrissey, Mist Mountain, and Elk formations. Is spelled Kootenai in the US where it is present in the Big Horn basin,Yellowstone province,Snake River basin,Montana folded belt province,Sweetgrass arch,Central Montana uplift and Powder River basin of Idaho and Montana
Up to 152 meters of Upper Cretaceous marine sandstone, shale, and conglomerate found in the Northern Canadian Rockies and the adjacent plains. Contains some pelecypods and cephalopods
Up to 100 meters of Early Cretaceous continental shale,sandstone,clay,and coal found in the Chadron arch,Powder River basin,and Williston basin of Nebraska,South Dakota and Wyoming. Where present, the Lakota is the oldest Cretaceous unit.
Up to 800 meters of non-marine Upper Cretaceous and Earliest Paleocene sandstone,siltstone,shale and coal found in the Powder River basin,Green River basin,Wind River basin, and Big Horn basin with plant,shells and dinosaur fossils.
320 meters of Lower Cretaceous shale and coal found in the Canadian Northwest Territories.
Fossils: Foraminifera, bivalve fragments, palynomorphs, fish scales, plant fragments.
An obsolete name for 30 meters of Jurassic continental sandstones and limestone found in Colorado(sw), New Mexico(nw), and Utah(se). It overlies the Dolores Formation and is overlain by the McElmo Formation. In modern usage, the La Plata beds are assigned to the Morrison and Entrada Formations.
Fossils: Sparse
Up to 250 meters of non-marine late Upper Cretaceous clay and sandstone found in the Denver basin or Colorado. Contains some plant fossils
Up to 600 meters of Late Cretaceous sandy marine shales found in the Big Horn basin,Green River basin,Powder River basin,San Juan basin Wind River basin of Colorado,New Mexico,Utah and Wyoming
Up to 417 meters of Middle to Late Triassic dolomitic sandstone and siltstone with minor limestones found in the plains of NorthEast British Columbia
Up to 270 meters of late Cretaceous shale with siltstone, calcite, and ironstone concretions. Found in NorthEast Alberta and adjacent Saskatchewan
100 meters of Middle Tertiary conglomerate found in New Mexico(sw). It overlies the Mojado formation and is overlain by Tertiary lavas.
Fossils:
Up to 2300 meters of Upper Cretaceous continental shales, sandstones and conglomerates found in the Central Montana uplift and folded belt provinces of Southwest Montana. Fossils include abundant leaves in the basal beds and some fresh water mollusks.
up to 600 meters of Eocene shale,limestone,conglomerate and sandstone found in New Mexico(sw). It overlies igneous rocks/El Paso/Bliss/Montoya/Fusselman/Mojado/Gym beds and is overlain by the Rubio Peak Formation/Sarten Sandstone
Fossils: None
350 meters of heterogeneous marine sediments -- Limestone,Dolomite,Sandstone, Shale,Conglomerate -- found in Arizona(se). It corresponds to parts of the Mural Limestone and Morita Formation. It overlies the remainder of the Morita Formation and is overlain by the remainder of the Mural Limestone. It is a member of the Bisbee Group
Fossils: Unknow. Probably some marine invertebrates
At least 600 meters of fossiliferous Triassic sandstone and silty/sandy limestone in Northern British Columbia Rocky Mountain foothills. Considered to be part of the Schooler Creek Group.
Up to 260 meters of Late Permian and/or Early Triassic redbed sandstone, shale, and minor limestone found in the Las Animas arch,Las Vegas-Raton basin,Denver basin of eastern Colorado where it occupies the interval between Permian formations below and the Jurassic Morrison formation. Fossils are reported to be present.
Up to 1000 meters of Late Cretaceous marine shale with minor sandstone. It is widely distributed in Arizona,Colorado,New Mexico,Utah and Wyoming.
Up to 145 meters of Cretaceous continental and marine sandstone and shale near shore marine and terrestrial sandstone and shale found in the central plains of Alberta.
Up to 400 meters of Upper Cretaceous marine shale and sandstone found in the folded belt and Sweetgrass Arch provinces of Northwest Montana. Ammonites found. Part of the Colorado Group.
Up to 400 meters of Upper Cretaceous and/or Paleocene non-marine sandstone,shale,and conglomerate found in the San Juan basin of Colorado and New Mexico. Occupies interval between the Kirtland and Ojo Alamo formations. Plants and vertebrate fossils.
An obsolete name for up to 300 meters of sandstone and shale of the Jurassic Morrison Formation found in Colorado(sw), New Mexico(nw) and Utah(se). It overlies the La Plata Sandstone/Entrada Formation/Carmel Formation and is overlain by the Dakota Formation
Fossils: plants? Vertebrates?
Up to 2000 meters of non-marine Upper Cretaceous sandstone,siltstone,shale and coal found in the Green River Basin of Wyoming with plant and dinosaur fossils.
Up to 350 meters of Late Cretaceous sandstone,shale,coal and tuff found in the Wind River basin and the Big Horn basin of Wyoming. Plant fossils.
Up to 1400 meters of non-marine Upper Cretaceous sediments widely exposed in Arizona,Colorado,Idaho,Montana,New Mexico,Utah,and Wyoming. Consists of heterogeneous sediments -- mostly shale, marl, coal and sandstone sandwiched between two massive sandstone layers that separate the Mesaverde from marine shales/limestones that overlay and underlay it. Fossil vertebrates have been found, but are rare.
Up to 113 meters of fossiliferous Upper Cretaceous near shore marine and terrestrial sandstone and shale found in the Southern plains of Alberta.
Up to 500 meters of Triassic shale and sandstone with thin gypsum layers found in the Paradox basin,Piceance basin,Uinta basin,Plateau sedimentary province,Black Mesa basin,San Juan basin,Green River basin,Great Basin province,Palo Duro basin,Las Vegas-Raton basin, and Orogrande basin of Arizona,California,Colorado,Nevada,New Mexico and Utah. Sparse marine and lacustrine fossils reported
1500 meters or more of Cretaceous sandstone and shale found in New Mexico(sw). It overlies the U-bar formation and is overlain by the Cowboy Spring formation/Ringbone Formation/Little Formation/Lobo Formation. It is a member of the Bisbee Group
Fossils: Marine invertebrates-gastropods, ammonites, mollusks, pelecypods in upper part.
Up to 280 meters of dark Triassic siltstone and shale found in NorthEast British Columbia and NorthWest Alberta. In its area of exposure it is the oldest Mesozoic sediment and rests unconformally on Paleozoic sediments.
As much as 1400 meters of Lower Cretaceous marine sandstone and shale found in Arizona(SE) and New Mexico(sw). It overlies the Glance Conglomerate and is overlain by the Mural Limestone/Lowell Formation. It is a member of the Bisbee Group
Fossils: Sparse at best.
Up to 80 meters of brown to orange Uppermost Jurassic sandstone found in the Rocky Mountain and foothills of SouthWest Alberta and SouthEast British Columbia.
Up to 600 meters of fine grained Uppermost Jurassic and Early Cretaceous sandstone and shale found in the Rocky Mountain and foothills of Central Alberta and adjacent British Columbia.
Up to 200 meters of occasionally fossiliferous continental Upper Jurassic sandstone,clay and limestone and shale found in Anadarko basin,Big Horn basin,Black Mesa basin,Central Montana uplift,Chadron arch,Denver basin,Green River basin,Las Vegas-Raton basin,Montana folded belt province,North Park basin,Palo Duro basin,Paradox basin,Piceance basin,Plateau sedimentary province,Powder River basin,San Juan basin,San Luis basin,Sierra Grande uplift, Sweetgrass arch,Uinta basin,Wasatch uplift,Williston basin of Arizona,Colorado,Montana,North Dakota,New Mexico,Oklahoma,South Dakota,Utah,and Wyoming. Dinosaur remains and plants are abundant in some locations.
Up to 100 meters of fossiliferous Upper Cretaceous black shale with minor Sandstone found in the Big Horn basin,Central Montana uplift,Chadron arch,Denver basin,Green River basin,Montana folded belt province,North Park basin,Powder River basin,Sweetgrass arch,Uinta uplift,Williston basin,Wind River basin,Yellowstone province of Colorado,Montana,North Dakota,South Dakota,Utah,and Wyoming Fossils include fish scales and teeth.
Up to 1000 meters of Lower Cretaceous limestone and sandstone found in Arizona(se) and New Mexico(sw). It ovelies the Morita Formation/Lowell Formation and is overlain by the Cintura Formation/Hay Flat Limestone It is a member of the Bisbee Group
Fossils: Abundant marine mollusks. forams
More than 460 meters of unfossiliferous Late Triassic and/or Early Jurassic sandstone with a few thin limestone beds found in the Black Mesa basin,Great Basin province,Paradox basin,Piceance basin,Plateau sedimentary province,San Juan basin,Uinta basin and Uinta uplift of Arizona,Colorado,New Mexico,and Utah.
Up to 30 meters of very near shore Lower(?) Cretaceous black shale,sandstone,bentonite,and coal found in Williston basin,Powder River basin, and Chadron arch of Montana,North Dakota,Nebraska,South Dakota, and Wyoming.
Up to 400 meters of near shore marine and continental Late Jurassic and Early Cretaceous sandstone, grey shale and thin coals found in the North Central Rocky Mountains of Alberta.
Up to 230 meters of marine Uppermost Cretaceous limestone and/or shale found in the San Juan basin,Salina basin,Central Montana uplift,Powder River basin,Denver basin,Sioux uplift,Las Vegas-Raton basin,Williston basin,Iowa shelf,North Park basin of Colorado, Kansas,Minnesota,Montana,North Dakota,Nebraska,New Mexico,South Dakota and Wyoming. Contains marine vertebrates.
Up to 800 meters of Triassic and/or Jurassic sandstones with minor limestones and shales in some areas. Found in the Denver,Green River,Wind River and Snake River basins and Yellowstone province of Colorado,Idaho,Utah,and Wyoming. Possibly some ichnofossils
Up to 70 meters of Uppermost Cretaceous and Early Paleocene(?) shale and sandstone found in the San Juan Basin of New Mexico where it overlies the Kirtland formation and is overlain by the Puerco formation. Abundant vertebrate fossils-dinosaurs,turtles,fish teeth.
Up to 328m meters of Upper Cretaceous calcareous sandstone,shale,coal and bentonite found in Southern Alberta. Dinosaur remains and plant fossils are abundant It is the middle formation in the Judith River Group
Up to 50 meters of marine Lower Cretaceous Sandstone found in the Salina basin and Denver Basin of Colorado,Kansas,Nebraska,and Wyoming. The uppermost formation of the Dakota Group.
Up to 200 meters of Upper Cretaceous grey mudstone with some sandstone and siltstone found in the plains of Southern Alberta and Saskatchewan
Up to 137 meters of Triassic limestone and calcareous shale and siltstone with abundant bivalve fragments in some beds. Found in the Rocky Mountain foothills of NorthEast British Columbia. It is considered by some to be a part of the Schooler Creek Group
600 meters of Paleocene mudstone,siltstone,and sandstone with minor conglomerate,coal,limestone and bentonite with terrestrial vertebrate fossils and invertebrates in the limestones. Found in the Rocky Mountain foothills as well as exposures in the Northern, Western, and Central plains. May include some Cretaceous beds.
Up to 60 meters of Lower Cretaceous graywacke, sandstone, coal and shale found in the plains of Northern Alberta. Fossils include mollusks and starfish.
Up to 12 meters of Lower Cretaceous sandstone, siltstone and shale with often abundant carbonized plant fragments found in the plains of Northern Alberta.
Up to 83 meters of Cretaceous lacustrine algal limestone found Green River basin,Snake River basin,Wasatch uplift,and Yellowstone provinces of Idaho and Wyoming. Some fresh water invertebrate fossils. Part of the Gannett Group.
Up to 90 meters of fossiliferous Upper Cretaceous near shore marine sandstone exposed in the San Juan basin of Colorado and New Mexico.
Up to 1400 meters of fossiliferous Upper Cretaceous dark marine shales with minor clay,limestone,and sandstone and large concretions widely exposed in Colorado,Kansas.Minnesota,Montana,North Dakota,Nebraska,New Mexico,South Dakota and Wyoming.
Up to 200 meters of Latest Cretaceous/Early Paleocene conglomerate found in the Southwest part of the Yellowstone area of Wyoming.
Up to 100 meters of Jurassic marine shale,limestone,and dolomite interbedded with gypsum and redbeds. Found in the Central Montana uplift,Powder River,Williston,and Big Horn basins, and the Sweetgrass arch of Montana,North Dakota,and Wyoming. A few ammonites and gastropods found
1070 meters of Lower(?) Cretaceous shale and sandstone found in New Mexico(sw). It overlies the Corbett Sandstone and is overlain by the Skunk Ranch Conglomerate It is a member of the Bisbee Group
Fossils: non-marine mollusks, petrified wood in lower beds. Sometimes abundant marine invertebrates in the Upper beds.
Up to 1220 meters of Paleocene brown shale,calcareous sandstone and siltstone. With abundant fresh water mollusks in some beds. Exposed in the Porcupine Hills of Southwestern Alberta.
Up to 2600 meters of Early Tertiary sandstone,conglomerate,clay,marl, and shale found in the Las Vegas-Raton basin of Colorado. A few vertebrates (turtles) reported
Up to 430 meters of late Jurassic redbed sandstone found in the Green River,Uinta and Snake River basins, Uinta and Wasatch uplifts and Yellowstone province. Of Idaho, Utah, and Wyoming. Includes a 60 meter fossiliferous marine limestone.
Up to 100 meters of Lower Cretaceous largely marine sandstone,shale, and coal found in the Anadarko basin,Sierra Grande uplift,Palo Duro basin,Las Vegas-Raton basin, and Denver basin of Colorado,New Mexico,and Oklahoma. A few marine invertebrate fossils reported. Generally includes all the beds below the Dakota sandstone and above the Jurassic Morrison formation. Subdivisions include the Kiowa, Glencarin, and Tucamcari shales and the Cheyenne and Lytle Sandstone.
Up to 550 meters of very early Tertiary conglomerate,sandstone,coal, and shale found in the Las Vegas-Raton basin of Colorado or New Mexico. Some petrified wood and plant fossils reported.
Up to 244 meters of Paleocene and Uppermost Cretaceous claystone,sandstone,shale and coal found in the Eastend-Cypress Hills area of Southwest Saskatchewan.
Up to 700 meters of Middle Tertiary (Oligocene?, Micoene?) volcanic tuff and lava found in Arizona(se). It overlies the Faraway Ranch Formation
Fossils: None?
Up to 70 meters of abundantly fossiliferous marine Middle or Upper Jurassic shale and limestone found in the Central Montana uplift,Sweetgrass arch,Williston basin,and Montana folded belt province of Montana, North Dakota, and Wyoming.
Up to 280 meters of Cretaceous clay and shale found in SouthEast Saskatchewan and adjacent Manitoba and North Dakota.
Up to 2300 meters of Cretaceous sandstone,shale and conglomerate found in New Mexico(sw). It overlies the Mojado Formation, is contemperaneous with the Broken Jug Limestone and is overlain by Tertiary volcanics. It is a member of the Bisbee Group
Fossils: Cretaceous non-marine mollusks and plants
Up to 550 meters of Late Cretaceous sandstone,shale,and coal found in the Green River basin of Southwest Wyoming. Some of the sandstone and shale contain marine fossils
Up to 1500 meters of poorly dated Middle Tertiary volcanics and gravels found in New Mexico(sw). It overlies volcanics/Lobo Formation sediments and is overlain by volcanics.
Fossils: None? Plants in lakebeds that may be contemporaneous
A Latest Eocene or Earliest Oligocene sandstone formation found in Beaverhead County, MT. Vertebrate fossils
1500 meters of Upper Cretaceous volcanics and sediments found in Arizona(se). It overlies the Fort Crittenden Formation and is overlain by Tertiary beds
Fossils: None?
Up to 140 meters of Middle to Upper Triassic conglomeritic redbed sandstone interbedded with shale found below the Chinle formation in the Las Vegas-Raton basin,Palo Duro basin,Permian basin,Estancia basin,and Orogrande basin of New Mexico and Texas. In some places is mapped as undivided Dockum Group. Fossils include plant remains and vertebrate bones
Up to 100 meters of Lower and Middle Cretaceous sandstone and shale found in New Mexico(sw). It overlies the Santa Rosa Formation and is overlain by the Colorado Group/Dakota Formation
Fossils: marine molluscs in some beds.
Up to 45 meters of abundantly fossiliferous marine Jurassic sandstone,shale,and limestone found in the Central Montana uplift,Montana Folded Belt Province and Sweetgrass Arch of Idaho, Utah, and North Dakota.
Up to 85 meters of Uppermost Cretaceous and Lowest Paleocene sandstone, shale, mudstone, siltstone, and coal found in the westernmost part of the southern Alberta plains along the Red Deer River and adjacent areas
Up to 60 meters of marine Jurassic lithographic limestone capped with calcareous sandstone with abundant corals, pelecypods, gastropods, echinoids, algae. Found in the Southern Saskatchewan and adjacent Montana and North Dakota.
1200 meters of Lower Cretaceous shale,siltstone and sandstone with minor limestone found in Arizona(se). It overlies the Apache Canyon Formation and is overlain by the Turney Ranch Formation
Fossils: plants, bivalves
Up to 18 meters of Upper Triassic conglomerate capping up to 60 meters of sandstone found in the Black Mesa basin,Great Basin province,Orogrande basin,Paradox Basic,Plateau sedimentary province,and San Juan basin of Arizona,Colorado,Nevada, and Utah where it underlies the Chinle sandstone. Petrified wood is commonly found in the conglomerate.
Up to 100 meters of marine Lower Cretaceous shale found in the Denver,Powder River,and Williston basins of Colorado,Montana,North Dakota,Nebraska,South Dakota, and Wyoming. Dated from forams and other microfossils
About 1000 meters of Lower Cretaceous cobbles in a shale and sandstone matirx found in New Mexico(sw). It overlies the Playas Peak Formation and is overlain by middle-Tertiary volcanics. May be the same as the Ringbone Formation. It is the uppermost member of the Bisbee Group
Fossils: Unknown? Enough for dating?
Upper Cretaceous sediments found in Arizona(se). It overlies the Lower Cretaceous Bisbee Group and is overlain by the SaleroFormation/Tertiary volcanics. It includes the Fort Buchanan and Fort Crittenden formations.
Fossils: Some vertebrates -- dinosaurs,fish -- in the Fort Crittenden Beds
Up to 150 meters of Permian and Triassic redbed sandstone with thin gypsum interbeds found in the Williston basin, Powder River basin,Chadron arch,and Denver basin of Montana,North Dakota,Nebraska,South Dakota,and Wyoming.
Up to 348 meters of heterogeneous Lower Cretaceous clastic beds -- shale, sandstone, mudstone, ironstone, graywacke, coal -- found in the subsurface of the Northwestern plains of British Columbia and Alberta. Ammonites are present.
Up to 760 meters of Upper Cretaceous sandstone and friable shale with vertebrate bones. There are coal and fossiliferous marine limestones near base.
Up to 760 meters of marine Upper Cretaceous shale and Sandstone found in the Green River and Powder River basins of Montana and Wyoming with a few ammonites. Considered to be the basal member of the Cody Shale.
Up to 200 meters of mid to late Jurassic fossiliferous sandstone and siltstone with minor limestone found in the Green River and Snake River basins, Uinta and Wasatch uplifts and Yellowstone province. Of Colorado, Idaho, Utah, and Wyoming.
Up to 557 meters of Lower Triassic shale and sandstone found in the Rocky Mountain foothills of Alberta and British Columbia.
Up to 110 meters of Middle Jurassic shale and sandstone found in the Paradox basin and Plateau sedimentary province of Arizona,Colorado,New Mexico,and Utah. The basal beds are from a hypersaline marine environment, the upper beds are continental red beds.
Up to 70 meters of abundantly fossiliferous marine Middle or Upper Jurassic shale and sandstone with thin limestone beds found in the Big Horn basin,Central Montana uplift,Chadron arch,Denver basin, Green River basin,Montana folded belt province,North Park basin,Powder River basin,Uinta basin,Williston basin, and Wind River basin of Colorado,Idaho,Montana,Nebraska,South Dakota,Utah, and Wyoming.
At least 150 meters of Lower Cretaceous sandstone and clay with some plant fragments found in SouthWest Manitoba and adjacent Saskatchewan
Up to 50 meters of fossiliferous marine Upper Jurassic sandstone and shale found in the Sweetgrass arch,Montana folded belt province, Central Montana uplift,Williston basin,Powder River basin,Big Horn basin,Chadron arch, and Wind River basin of North Central Montana. assorted marine invertebrates.
16 meters of Upper Eocene soft sandstone and conglomeritic gravel with vertebrate faunas. Scattered Exposures SE of Swift Current, SK.
Late Eocene tuff,shale,conglomerate exposed at a few localities in the Wind River basin of Wyoming. vertebrate fossils.
Up to 300 meters of fossiliferous marine Upper Cretaceous shale and Sandstone found in the Sweetgrass arch,Williston basin,Montana folded belt province and Central Montana uplift of Montana and Wyoming.
Up to 70 meters of Middle to Upper Triassic red and yellow shales found below Trujillo formation sandstones in the,Palo Duro basin,Permian basin,Estancia basin,and Orogrande basin of New Mexico and Texas. In some places is mapped as undivided Dockum Group where it is the lowest member. Fossils include petrified logs
Up to 200 meters of Tertiary limestone conglomerate found in New Mexico(sw). It overlies the Cowboy Spring Formation/Mojado Formation and is overlain by Tertiary igneous rocks
Fossils: None
Up to 70 meters of Middle to Upper Triassic sandstone found in the Las Vegas-Raton basin,Palo Duro basin,Permian basin,and Anadarko basin of New Mexico and Texas. Overlies the Tecovas formation. In some places is mapped as undivided Dockum Group. Triassic fossils reported
Up to 1200 meters of fossiliferous Permian and Triassic marine shales, sandstones and limestones found in the Green River,Snake River,and Uintah basins, Uinta and Wasatch uplifts and Yellowstone province of Idaho, Montana, Nevada, Utah, and Wyoming. Fossils are reported to be present
Up to 100 meters of fossiliferous Upper Cretaceous black shale, Sandstone found in the Montana folded belt province,Big Horn basin,Chadron arch,Denver basin,Green River basin,Williston basin,Snake River basin,Wind River basin,Powder River basin, and Central Montana uplift provinces of Idaho,Wyoming, and Montana. It is the basal formation of the Colorado group. Fossils include plants and shark teeth.
Triassic calcareous siltstones with minor sandstone, shale and limestone found in British Colombia. Includes the Grayling formation.
As much as 70 meters of Upper Cretaceous sandstone found in the Las Vegas-Raton basin of Colorado and New Mexico. Fossils include fish and invertebrates.
1200 meters of Lower Cretaceous shale,siltstone,sandstone and bentonite found in Arizona(se). It overlies the Shellenberger Canyon Formation and is overlain by the Fort Crittenden Formation/Salero Formation. It is a member of the Bisbee Group
Fossils: Unknown
Up to 700 meters of Upper Cretaceous continental shale with minor sandstone and limestone found in the folded belt and Sweetgrass Arch provinces of Northwest Montana. Fossils include dinosaurs and some fresh water mollusks.
Almost 1200 meters of fossiliferous marine Jurassic shale,limestone and sandstone found in the Green River,Uinta and Snake River basins, Uinta and Wasatch uplifts and Great Basin and Yellowstone provinces. Of Idaho, Utah, and Wyoming.
Up to 86 meters of Upper Cretaceous sandstone and shale found Green River basin,Snake River basin,and Wasatch uplift of Idaho and Wyoming. The beds have been reassigned to the Bear River or Smiths formations.
1200 meters of Lower Cretaceous limestone with minor shale found in Arizona(se) and New Mexico(sw) It overlies the Hell-to-Finish Formation and is overlain by the Mojado Formation. It is a member of the Bisbee Group
Fossils: Sometimes abundant marine invertebrates
Up to 180 meters of calcareous Jurassic marine shale with sandstone in the middle layers. It is found in Southernmost Saskatchewan and adjacent Montana and North Dakota. It is sometimes considered a group with three formations -- the Masefield Shale, Roseray Formation, and Rush Lake Shale. Bivalves and ammonites are reported.
Up to 130 meters of Early Tertiary sandstone, shale, and coal found in the Las Vegas-Raton basin of Colorado and New Mexico. With abundant plant fossils in areas.
Up to 130 meters of terrestrial? Upper Cretaceous shales and marlstones found in Manitoba and adjacent Saskatchewan.
Up to 50 meters of terrestrial Cretaceous sandstone with minor conglomerates, chert and other rocks found in the subsurface of Southern Alberta and Saskatchewan. Plant fragments are abundant.
Up to 80 meters of Upper Cretaceous marine sandstone with some shale and concretions exposed in the Folded belt,Central Montana Uplift and Sweetgrass Arch regions of Montana and Wyoming. Fossils restricted to a few poorly preserved bivalves.
In excess of 200 meters of Late Eocene sandstone,siltstone,mudstone,tuffs and volcanic flows exposed in the Wind River basin of Wyoming. vertebrate fossils. Fossils include plants and vertebrates.
As much as 10 meters of fossiliferous Lower Cretaceous marine clay,sandstone,and limestone found in the Ouachita folded belt,Arkla basin,East Texas basin,Strawn basin,Llano uplift,Kerr basin, Permian basin,South Oklahoma folded belt,and Fort Worth synclines of Arkansas,Louisiana,New Mexico,Oklahoma,and Texas. Overlies the Antlers formation in many areas
Unfossiliferous sandstone with minor coal and conglomerate found in river bank exposures in Northern plains.
Almost two kilometers of Late Paleocene and Eocene shale and sandstone found in the Wasatch uplift, Uinta uplift, Green River basin, Piceance basin, Powder River basin, Uinta basin, Paradox basin, Colorado Plateau, Yellowstone province, San Juan basin of Colorado, Idaho, New Mexico, Utah,Wyoming.
Roughly 4km of fossiliferous Lower Cretaceous sandstone and shale found in Green River basin,Snake River basin, and Wasatch uplift of Idaho and Wyoming
6 meters of non-marine bentonitic shale and sandstone found along the North Saskatchewan and Red Deer Rivers near Edmonton, AB.
At least 300 meters of Eocene and Oligocene siltstone,sandstone,conglomerate,and volcanic tuff exposed in the Wind River, Denver, and Williston basins as well as the Sioux uplift and Chadron Arch of Colorado, Montana, North Dakota,Nebraska,South Dakota and Wyoming. Abundant plant and vertebrate fossils.
Middle to Late Eocene to Oligocene conglomerate,sandstone,lava breccias and clay exposed in the Bighorn and Wind River Basins as well as the Yellowstone region of Wyoming.
At least 600m of Eocene floodplain sediments exposed in the Bighorn basin of Wyoming. Not to be confused with the marine(?) Wildwood Formation, also Eocene, of New Jersey.
As much as two kilometers of Upper Jurassic/Lower Cretaceous conglomerate, sandstone and siltstone found in Arizona(se). It overlies the Glance Conglomerate and is overlain by the Apache Canyon Formation. The name conflicts with the a formation of the same name in Nevada and it is unclear what name will be used by future authors. It is a member of the Bisbee Group
Fossils: Fresh water gastropods, petrified wood
Early(?) Eocene abundantly fossiliferous sandstones and claystones found in the Wind River Basin of Wyoming.
Up to 1006m of varicolored shale with concretions and grey sandstone found in the plains of SouthWest Alberta and adjacent Montana.
Up to 150 meters of unfossiliferous red Late Triassic and/or Early Jurassic sandstone with a few thin limestone beds found in the Black Mesa basin,Paradox basin,Plateau sedimentary province,and San Juan basin of Arizona,Colorado,New Mexico,and Utah. Underlies the Navajo formation where the latter is present. Contains a very few dinosaur tracks?
Up to 400 meters of Permian and Lower Triassic redbed sandstones and shales found in the Uinta and Wasatch uplifts and Snake River and Green River basins of Colorado,Idaho,Montana,Utah,and Wyoming. Abundant bivalves in some beds near the top.
Alberta
Higher resolution map -
Arizona
High Resolution map -
British Columbia
There are several maps at varying resolutions at http://www.empr.gov.bc.ca/MINING/GEOSCIENCE/PUBLICATIONSCATALOGUE/DIGITALGEOLOGYMAPS/Pages/default.aspx. http://www.empr.gov.bc.ca/MINING/GEOSCIENCE/PUBLICATIONSCATALOGUE/DIGITALGEOLOGYMAPS/Pages/default.aspx
They are all huge. This is the smallest
Colorado
High Resolution map -
Idaho
High Resolution map
Kansas
High Resolution map
Minnesota
High Resolution map
Montana
High Resolution map
North Dakota
High Resolution map
Nebraska
High Resolution map
New Mexico
High Resolution map
Oklahoma
High Resolution map
South Dakota
High Resolution map
Texas
High Resolution map
Utah
High Resolution map
Wyoming
High Resolution map
Yukon
No bedrock map of the Yukon found on-line. It's this or nothing
[http://web.archive.org/web/20091231184415/http://fossilsoftexas.webs.com/]
Copyright 2006-2012 Donald Kenney (Donald.Kenney@GMail.com). Unless otherwise stated, permission is hereby granted to use any materials on these pages under the Creative Commons License V2.5.
This page will have been validated as Valid HTML 4.01 Transitional prior to posting on the web site. W3C Logo Image omitted.
