Fox Hills 

Sandstone 

0 

1,000 

2,000 

1,500 

500 

3,000 

2,500 

Pierre 

Shale 

 Niobrara 

Formation 

Fort Hays Limestone Member 

Pseudoperna congesta 

Mitten Member 

Buckeye—Larimer County, CO—Sec. 2, T. 10 N., R. 69 W., 

Secs. 17–20, T. 11 N., R. 68 W., Secs. 22, 27, 34, 35, T. 11 N., R. 69 W.

5,000 

Exiteloceras jenneyi (fig. 2, zone 66) 

Cremnoceramus deformis (fig. 2, zone 40) 

6,000 

6,500 

7,500 

Baculites clinolobatus (fig. 2, zone 75) 

Hygiene Sandstone Member 

Baculites gregoryensis (fig. 2, zone 61) 

Baculites perplexus (fig. 2, zone 60) 

Didymoceras nebrascense (fig. 2, zone 64) 

Baculites grandis (fig. 2, zone 74) 

5,500 

7,000 

Baculites scotti (fig. 2, zone 63) 

Smoky Hill Member 

Carlile Shale 

Greenhorn 

 Limestone 

Sharon Springs Member 

Inoceramus ginterensis (fig. 2, zones 16–18) 

3,500 

8,000 

8,500 

9,000 

9,500 

4,000 

Gammon Member 

Baculites obtusus (fig. 2, zone 56) 

Baculites maclearni (fig. 2, zone 57) 

Baculites asperiformis (fig. 2, zone 58) 

Baculites perplexus (fig. 2, zone 60) 

concealed 

Unnamed member 

Terry Sandstone Member 

Unnamed shale member (part) 

Didymoceras cheyennense (fig. 2, zone 67) 

Baculites cuneatus (fig. 2, zone 69) 

Rocky Ridge Sandstone Member 

Baculites reesidei (fig. 2, zone 70) 

Unnamed sandy shale member 

Larimer Sandstone Member 

Unnamed shaly sandstone member Baculites reesidei (fig. 2, zone 70) 

Richard Sandstone Member 

Baculites jenseni (fig. 2, zone 71) 

Unnamed shale member 

Baculites baculus 

 

Baculites eliasi (fig. 2, zone 72) 

Unnamed sandstone member 

Unnamed upper shale member 

Baculites baculus (fig. 2, zone 73) 

Upper transition member 

Baculites sp. 

Endocostea typica 

Codell Sandstone and Blue Hill Members 

Mytiloides mytiloides (fig. 2, zone 27) 

Ostrea beloiti (fig. 2, zones 12–15) Graneros 

 Shale Conlinoceras gilberti (fig. 2, zone 9 ) 

(fig. 2, zone 73) 

Baculites eliasi (fig. 2, zone 72) 

Baculites asperiformis(fig. 2, zone 58) 

Baculites asperiformis (fig. 2, zone 58) 

Baculites asperiformis (fig. 2, zone 58) 

Baculites maclearni (fig. 2, zone 57) 

 Laramie 

Formation 

 Mostly 

 continental 

 sandstone, 

siltstone, and 

 shale, and 

 coal. 

4,500 

 Fox Hills 

Sandstone 

0 

1,000 

2,000 

1,500 

500 

3,000 

2,500 

Pierre 

Shale 

 Niobrara 

Formation 

Fort Hays Limestone Member 

Lykins Gulch—Boulder County, CO—

T. 1–2 N., R. 69–70 W.

5,000 

Cremnoceramus deformis dobrogensis (fig. 2, zone 40) 

6,000 

6,500 

7,500 

Baculites clinolobatus (fig. 2, zone 75) 

Baculites gregoryensis (fig. 2, zone 61) 

Baculites grandis (fig. 2, zone 74) 

5,500 

7,000 

Baculites scotti (fig. 2, zone 63) 

Smoky Hill Member 

Carlile 

 Shale 

Greenhorn 

Limestone 

Acanthoceras amphibolum (fig. 2, zone 13) 

3,500 

8,000 

4,000 

Watinoceras coloradoense (fig. 2, zone 26) 

Baculites perplexus (fig. 2, zone 60) 

Middle shale member (part) 

Baculites reesidei (fig. 2, zone 70) 

Baculites reesidei (fig. 2, zone 70) 

Richard, Larimer, and Rocky 

 Ridge Sandstone Members 

 and intervening unnamed 

 shale members, undivided 

Baculites eliasi 

(fig. 2, zone 72) 

Unnamed upper shale member 

Baculites baculus (fig. 2, zone 73) 

Upper transition member 

Graneros 

 Shale Conlinoceras tarrantense (fig. 2, zone 9) 

Baculites asperiformis (fig. 2, zone 58) 

 Laramie 

Formation 

Continental 

 sandstone, 

 siltstone, 

 claystone 

 and minor 

 coal. 

4,500 

Arapahoe 

Formation 

Conglomerate 

and sandstone. 

Baculites clinolobatus (fig. 2, zone 75) 

Hygiene Sandstone Member 

Lower shale member 

 (consists of Mitten, Sharon 

 Springs, and Gammon Members) 

Mowry 

 Shale 

 (part) 

Baculites jenseni (fig. 2, zone 71) 

Baculites obtusus (fig. 2, zone 56) 

Bridge Creek 

Member 

Hartland Shale and Lincoln Members 

 Fox Hills 

Sandstone 

0 

1,000 

2,000 

1,500 

500 

3,000 

2,500 

Pierre 

Shale 

 Niobrara 

Formation 

Scaphites whitfieldi (fig.2, zones 34–35) Fort Hays Limestone Member 

Collignoniceras woollgari (fig. 2, zone28) 

Pseudoperna congesta (fig. 2, zones 33–49) 

Dakota 

 Group 

Juana Lopez Member 

Blue Hill Member 

Fairport Member 

Kassler/Littleton area—Jefferson and Douglas 

Counties, CO—T. 5–7 S., R. 68–69 W.

Exiteloceras jenneyi (fig. 2, zone 66) 

Clioscaphites choteauensis (fig. 2, zone 47) 

Cremnoceramus deformis (fig. 2, zone 40) 

5,000 

5,500 

6,500 

Graneros 

 Shale 

Baculites asperiformis (fig.2, zone 58) 

Baculites sp. 

Informal Tepee Butte limestone of Scott, 1962 

Hygiene Sandstone Member 

Baculites gregoryensis (fig. 2, zone 61) 

Baculites scotti (fig. 2, zone 63) 

Anapachydiscus? complexus 

Didymoceras nebrascense (fig. 2, zone 64) 

Baculites rugosus (fig. 2, zone 66) 

Baculites eliasi (fig. 2, zone 72) 

Baculites baculus (fig. 2, zone 73) 

Baculites clinolobatus (fig. 2, zone 75) 

Baculites grandis (fig. 2, zone 74) 

4,500 

6,000 

Baculites scotti (fig. 2, zone 63) 

Smoky Hill Shale Member 

Carlile Shale 

Greenhorn 

Limestone 

Lincoln Member 

Hartland Shale Member 

Bridge Creek Member Inoceramus pictus (fig. 2, zones 19–22) 

Calycoceras canitaurinum (fig. 2, zone 15) 

Lytle Formation 

South Platte Formation 

Inoceramus bellvuensis (upper Albian) 

Baculites clinolobatus (fig. 2, zone 75) 

 Laramie 

Formation 

 Mostly 

 continental 

 claystone, 

 siltstone, 

 sandstone, 

conglomerate, 

 and coal. 

Dawson 

 Arkose 

 (part) 

 Mostly 

 continental 

 shale, 

 sandstone, 

conglomerate, 

 and coal. 

7,000 

7,500 

8,000 

3,500 

 

Rusty zone of Gilbert, 1897 

 Trinidad 

Sandstone 

0 

1,000 

2,000 

1,500 

500 

3,000 

2,500 

3,500 

Pierre 

Shale 

 Niobrara 

Formation 

Fort Hays Limestone Member 

Carlile Shale 

Trinidad/Aguilar area—Las Animas 

and Huerfano Counties, Colorado

Sec. 26, T. 29 S., R. 64 W.; 

Sec. 6, T. 30 S., R. 65 W. 

Blue Hill Member 

 Vermejo 

Formation 

 Raton 

Formation 

 (part) 

Juana Lopez and 

Codell Sandstone Members 

Mytiloides scupini (fig. 2, zone 37) Inoceramus perplexus (fig. 2, zone 34) 

Fairport Member 

Greenhorn 

Limestone 

Bridge Creek Member 

Hartland Shale Member 

Lincoln Member 

Graneros 

 Shale 

 Dakota 

Sandstone 

 (part) 

Baculites compressus (fig. 2, zone 68) 

Baculites grandis (fig. 2, zone 74) 

Inoceramus prefragilis (fig. 2, zones 14,15) 

Mytiloides mytiloides (fig. 2, zone 27) 

? 

Smoky Hill Member 

Baculites codyensis (fig. 2, zones 45–46) 

Ostrea beloiti (fig. 2, zones 12–15) Calycoceras sp, Borissiakoceras sp (fig. 2, zone 9) 

Thatcher Limestone Member 

 Trinidad 

Sandstone 

0 

1,000 

2,000 

1,500 

500 

3,000 

2,500 

3,500 

Pierre 

Shale 

Lower shaly unit 

 Niobrara 

Formation Smoky Hill Member 

Scaphites hippocrepis III (fig. 2, zone 53) 

Fort Hays Limestone Mbr. Mytiloides incertus (fig. 2, zones 36) 

Carlile 

 Shale Collignoniceras woollgari (fig. 2, zone 28) 

Greenhorn 

Limestone 

Graneros 

 Shale 

 Dakota 

Sandstone 

 (part) 

Area of Continental Oil Co. No. 3—

Colfax County, NM—

Sec. 18, T. 30 N., R. 22 E. 

Upper shaly unit 

Sandy unit 

(Apache Creek Sandstone Member?) 

Scaphites hippocrepis II (fig 2, zone 52) 

Cremnoceramus erectus (fig. 2, zone 39) 

Scaphites hippocrepis I (fig. 2, zone 51) 

Desmoscaphites bassleri (fig. 2, zone 49) 

Desmoscaphites erdmanni (fig. 2, zone 48) Clioscaphites choteauensis (fig. 2, zone 47) 

Clioscaphites vermiformis (fig. 2, zone 46) 

Cladoceramus undulatoplicatus (fig. 2, zone 45) 

Cremnoceramus deformis (fig. 2, zone 40) 

Cremnoceramus browni (fig. 2, zone 41) 

Protexanites bourgeoisianus (fig. 2, zone 44) 

Blue Hill Member 

Fairport Member 

Bridge Creek Mbr. 

Hartland Shale Member 

Lincoln Mbr. 

Mytiloides mytiloides (fig. 2, zone 27) 

Metoicoceras geslinianum (fig. 2, zone 20) 

Ostrea beloiti (fig. 2, zones 12–15) 

Inoceramus prefragilis (fig. 2, zones 14, 15) 

Baculites reesidei (fig. 2, zone 70) 

Baculites perplexus (fig. 2, zone 60) 

Baculites gregoryensis (fig. 2, zone 61) 

Baculites scotti (fig. 2, zone 63) 

Didymoceras stevensoni (fig. 2, zone 65) 

Exiteloceras jenneyi (fig. 2, zone 66) 

Didymoceras cheyennense (fig. 2, zone 67) 

Fossils were projected into the Niobrara Formation and 

Pierre Shale of the section from outcrop data to the south. 

 Vermejo 

Formation 

 Raton 

Formation 

 (part) 

 Trinidad 

 Sandstone 

0 

1,000 

2,000 

1,500 

500 

3,000 

2,500 

3,500 

Pierre 

Shale 

Upper transition member 

Lower member 

Sharon Springs Member 

Middle member 

 Niobrara 

Formation Smoky Hill Member 

Baculites reesidei (fig. 2, zone 70) 

Exiteloceras jenneyi (fig. 2, zone 66), Didymoceras stevensoni (fig. 2, zone 65), Baculites scotti (fig. 2, zone 63), Baculites gregoryensis (fig. 2, zone 61), 

Baculites perplexus (fig. 2, zone 60) 

Scaphites hippocrepis III, Glyptoxoceras sp. (fig. 2, zone 53) 

Cladoceramus undulatoplicatus (fig. 2, zone 45) 

Scaphites hippocrepis II & I, Scaphites leei III, 

Desmoscaphites bassleri, Desmoscaphites 

erdmanni, Clioscaphites choteauensis, 

Clioscaphites vermiformis, Cladoceramus 

undulatoplicatus 

Protexanites bourgeoisianus, Magadiceramus 

subquadratus 

Volviceramus grandis, Cremnoceramus 

browni, Cremnoceramus deformis (fig. 2, zones 40, 41) 

Fort Hays Limestone Member Mytiloides incertus (fig. 2, zone 36) 

Carlile 

Shale 

Collignoniceras woollgari (fig. 2, zone 28) 

Inoceramus dimidius (fig. 2, zones 31–33) 

Greenhorn 

Limestone 

Graneros 

 Shale 

 Dakota 

Sandstone 

 (part) 

Juana Lopez Member 

Blue Hill Member 

Fairport Member 

Bridge Creek Member 

Hartland Shale Member 

Lincoln Member 

Springer area—Colfax County, NM—

T. 24–25 N., R. 21–24 E.

 (fig. 2, zones 45–52) 

 (fig. 2, zone 44) 

Pierre 

Shale 

Pueblo area—Pueblo County, CO—Secs. 9, 10, and 35, T. 19 S., R. 64 W.; 

Secs. 14, 23, 25, and 35, T. 19 S., R. 65 W.; Secs. 2, 10, 15, 16, and 21, T. 20 S., R. 64 W.; 

Secs. 32–36, T. 20 S., R. 65 W.; Secs. 24 and 25, T. 20 S., R. 66 W. 

Cone-in-cone zone of Lavington (1933) 

 Niobrara 

Formation 

Fort Hays Limestone Mbr. 

Carlile 

 Shale 

Collignoniceras woollgari (fig. 2, zone 28) 

Greenhorn 

Limestone 

Graneros 

 Shale 

 Dakota 

Sandstone 

 (part) 

Cremnoceramus deformis erectus (fig. 2, zone 39) Cremnoceramus deformis dobrogensis (fig. 2, zone 40) 

Blue Hill Member 

Fairport Member 

Bridge Creek Mbr. 

Hartland Shale Mbr. 

Lincoln Mbr. 

Juana Lopez Mbr. 

Codell Sandstone Mbr. 

Smoky Hill Member 

Inoceramus simpsoni (fig. 2, zones 48–53 ) 

 Sphenoceramus sp. (fig. 2, zones 48–50) 

Cordiceramus cordiformis (fig. 2, zone 46) 

Cladoceramus undulatoplicatus (fig. 2, zone 45) 

Volviceramus involutus (fig. 2, zone 43) 

Mytiloides scupini (fig. 2, zone 37) Prionocyclus wyomingensis (fig. 2, zone 33) Inoceramus howelli (fig. 2, zones 29–30) 

Prionocyclus hyatti (fig. 2, zone 30) 

Calycoceras canitaurinum (fig. 2, zone 15) 

Acanthoceras amphibolum (fig. 2, zone 13) Conlinoceras tarrantense (fig. 2, zone 9) 

Mytiloides mytiloides (fig. 2, zone 27) Sciponoceras gracile (fig. 2, zones 19–21) 

Didymoceras cheyennense (fig. 2, zone 67) 

Baculites compressus (fig. 2, zone 68) Baculites cuneatus (fig. 2, zone 69) 

Baculites reesidei (fig. 2, zone 70) 

Baculites jenseni (fig. 2, zone 71) 

Baculites eliasi (fig. 2, zone 72) 

Baculites baculus (fig. 2, zone 73) 

Baculites grandis (fig. 2, zone 74) 

Upper transition 

member 

Baculites clinolobatus (fig. 2, zone 75) 

Tepee zone of Gilbert (1897) 

Sharon Springs Member 

Rusty zone of Gilbert (1897) 

Apache Creek Sandstone Member 

Transition member 

Didymoceras stevensoni (fig. 2, zone 65) 

Didymoceras nebrascense (fig. 2, zone 64) 

Baculites scotti (fig. 2, zone 63) 

Didymoceras jorgenseni (fig. 2, zone 63) 

Didymoceras binodesum (fig. 2, zone 63) 

Menuites complexus (fig. 2, zone 63) 

 

Baculites gregoryensis (fig. 2, zone 61) 

Baculites perplexus (fig. 2, zone 60) 

Baculites asperiformis (fig. 2, zone 58) 

Baculites obtusus (early form) (fig. 2, zone 56) 

Baculites sp. (weak flank ribs) (fig. 2, zone 55) 

Baculites sp. (smooth) (fig. 2, zone 54) 

Exiteloceras jenneyi (fig. 2, zone 66) 

2,000 

2,500 

3,000 

3,500 

4,000 

4,500 

5,000 

5,500 

6,000 

6,500 

 Fox Hills 

Sandstone 

1,000 

0 

500 

1,500 

 Laramie 

Formation 

7,000 

48 miles 

85 miles 

63 miles 

44 miles 

35 miles 

Calycoceras gilberti (fig. 2, zone 9) 

Calycoceras canitaurinum (fig. 2, zone 15) 

Inoceramus ginterensis (fig. 2, zones 16–18) 

Mytiloides mytiloides (fig. 2, zone 27) 

? 

? 

? ? 

? 

? ? ? 

? ? 

Inoceramus dunveganensis ? 

(fig. 2, zone 13) 

 * * * * 

 * * * * 

 * * * * 

 * * 

Scaphites mariasensis (fig. 2, zone 38) 

 * * * * 

 * * * * 

 * * * * 

 * * * * 

 * * * * 

 * * * * 

 * ? * ? 

EXPLANATION

Conglomerate

Sandstone

Sandstone with 

 shale partings

Sandstone, 

 calcareous

Siltstone

Shale

Shale with

 sandstone lenses

Limestone

Bentonite

Shale, 

 calcareous

Shale, 

 carbonaceous

Limestone, shaly

 * * * * Disconformity

Contact of 

 formations

Probable 

 correlation 

 of strata 

? ?

Approximate 

 contact of 

 formations

??

Approximate 

 correlation 

 of strata 

Possible

 disconformity 

B C

NORTH-CENTRAL COLORADO NORTHEASTERN NEW MEXICO 

54 miles 

 Raton 

Formation 

(part) and 

 Vermejo 

Formation, 

undivided 

Middle shale member (part) 

Terry (?) Sandstone Member 

4,000 

Thatcher Limestone Mbr. 

 * * * * 

Ardmore Bentonite Bed Prionocyclus hyatti (fig. 2, zone 30) 

Montezuma Valley Shale 

Cremnoceramus waltersdorfensis (fig. 2, zone 38) 

Codell Sandstone Mbr. 

Codell Sandstone and Blue Hill Members * ? * ? 

? ? 

? 

? ? 

 * * * ? ? ? ? ? 

 ? ? 

Clay Spur Bentonite Bed 

Marker (gray-red) bentonite 

Bridge Creek Member 

Hartland Shale/Lincoln Members 

 * * * * 

C 

C 

C Concealed * ?? * 

Unnamed member 

? 

Cremnoceramus deformis erectus (fig. 2, zone 39) 

Cremnoceramus deformis erectus (fig. 2, zone 39) 

Mytiloides mytiloides (fig. 2, zone 27) 

Plesiacanthoceras wyomingense (fig. 2, zone 14) 

Marker (gray-red) bentonite Dunveganoceras albertense (fig. 2, zones 17) 

Scaphites whitfieldi (fig. 2, zones 34, 35) 

Scaphites hippocrepis (fig. 2, zones 51–53) 

Phlycticrioceras oregonense (fig. 2, zone 44) 

Inoceramus rotundatus (fig. 2, zone 39) 

 * ? ? * 

 * ? ? * 

 * ? ? * 

 * ? ? * 

 * ? ? * 

FEET 

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Composite Biostratigraphic Outcrop Sections for Upper Cretaceous Formations along a South-trending Transect from Northeastern Wyoming to North-Central Colorado

By

E.A. Merewether, W.A. Cobban, and J.D. Obradovich

2011

Scientific Investigations Map 3175

 Sheet 2 of 2

U.S. Department of the Interior 

U.S. Geological Survey