PROFESSIONAL PAPER 1411-A

= Stratigraphic and hydrogeologic nomenclature—TABLE 1
a U.S. DEPARTMENT OF THE INTERIOR Geldon, A.L., 2002, Geology of Paleazoic rocks in the Upper Colorado River Basin in
science forachanging world U.S. GEOLOGICAL SURVEY Arizona, Colrado, New Mexico, Utah, and Wyoming, excluding the San Juan Basin
FOOTNOTES
. . , - . . . . . 7 . . . . . . woe . . 1. As suggested by McKelvey and others (1959), designation of the rocks of Park City/Phosphoria
Table 1.—Generalized stratigraphic and hydrogeologic nomenclature of Precambrian, Paleozoic, and Mesozoic rocks in the Upper Colorado River Basin [only Mesozoic formations immediately overlying the Paleozoic rocks are listed. Abbreviations used in this 00 tog arti oP A ae be rk
table include: Fm = Formation; Mor = Member; Ss = Sandstone; Ls = Limestone; Dol = Dolomite; Sh = Shale. Colors relate component geologic units to hydrogeologic units and are symbolic of the predominant lithology in the hydrogeologic unit: Ce eae ence) peers gomme te el used ny
yellow and brown indicate sandstone and quartzite; shades of green indicate mostly shale; shades of blue indicate mostly carbonate rocks; other colors indicate mixed lithology. Contacts within series are generalized] 2. Of Shaw (1957); included in Open Door Limestone in some reports (for example, Keefer
and Van Lieu, 1966).
3. Of Maughan (1980); also called South Canyon Creek Member (by Freeman, 1971, for example).
4. Of Johnson (1989); formerly considered a member of the State Bridge Formation (Freeman, 1971).
SOUTHWESTERN WYOMING NORTHWESTERN COLORADO NORTHEASTERN UTAH SOUTHEASTERN UTAH NORTHEASTERN ARIZONA SOUTHWESTERN COLORADO naan lURE 5. Of Langenheim (1952); also called “Minturn Formation."
ERA OR PERIOD OR EPOCH OR SERIES HYDROGEOLOGIC. THICKNESS 6. The name “Mackentire Tongue of Woodside Shale," as used by McKelvey and others (1959), is applied
ERATHEM SYSTEM , . ’ — Northern ; UNIT " to a sequence of red shale within the Park City Formation in the Uinta Mountains, even though the
Overthrust Wind River Rawlins Eastern White River Elk Southeastern Southwestern San Rafael Henry Monument Marble Defiance Four Corners San Juan IN FEET Woodside Shale generally is considered to be Triassic. Therefore, either the Mackentire Tongue is
Belt Mountains Uplift Eagle Basin Plateau Mountains Uinta Mountains Uinta Basin Swell Mountains Basin Upwarp Platform Plateau Platform Mountains not a tongue of the Woodside Shale, or the Woodside Shale is partly Permian.
7. As indicated by Hallgarth (1959) and correlations made during this study, the lowermost beds of the

Late or Madison Limestone in the southeastern Uinta Mountains correlate with the uppermost beds of the

Upper Dyer Dolomite of northwestern Colorado. Therefore, either the uppermost Dyer Dolomite is Mississippian,
as shown here, or the lowermost Madison Limestone in the southeastern Uinta Mountains is Late Devonian.

JURASSIC Middle : 8. According to Untermann and Untermann (1954), fossils from the upper (shaly) part of the Lodore
= earkror Jl Not discussed Formation where it crops out in the southeastern Uinta Mountains date the upper part of the Lodore
arly OF in this report. Formation (an equivalent of the Gros Ventre Formation) as Late Cambrian. However, the lower part of the

Lower Yeroleetey: Lodore Formation (an equivalent of the Flathead Sandstone, Sawatch Quartzite, and Tintic Quartzite) is

re) ly, )- unfossiliferous. The age of the lower part of the Lodore Formation here is inferred to be Middle and
= Late Cambrian from its geographic position relative to equivalent quartzite/sandstone units. These
Ci Not discussed formations range from Middle Cambrian on the north and west to Late Cambrian on the east.
fe) Late or ae NN in this report.
a Upper | _ _ (See Freethey 9. Even though the Morgan Formation is considered to be Middle Pennsyivanian where it crops out in
Ww pp Chinle Formation: i and Cordy, 1991) the Uinta Mountains (for example, Hansen and others, 1983), it can be traced southward in the
S ’ i, - subsurface into beds of the Elephant Canyon Formation of Baars (1962). Because the Elephant Canyon
TRIASSIC io : Formation is Early Permian where it crops out in the Monument Upwarp, both the Morgan and Elephant
on Canyon Formations must be Pennsylvanian and Permian in age where they merge (north of the San
- Rafael Swell).
Early or 10. The Round Valley Limestone correlates in the subsurface with the Eagle Valley Evaporite and the

Lower >> __— — ke aa re ee : ~ <= iy Paradox Member of the Hermosa Formation, both of which are Middle Pennsyivanian in age. Because

a= aor nis (oy eS — ~ —_— = eo : the Round Valley Limestone where it crops out in the Uinta Mountains is Early Pennsylvanian, it is

tt at inferred to be time-transgressive in the subsurface. Hence, in the southwestern Uinta basin, where it
a. merges with the Paradox Member, the Round Valley Limestone is interpreted to be Early and Middle
GZ Pennsylvanian. Similarly, the Doughnut Shale (Formation) is interpreted to be time-transgressive and

Late or Gu adalupi an is considered Late Mississippian and Early Pennsylvanian in the southwestern Uinta basin.

Upper 11. The Cutler Formation in southeastern Utah becomes divisible into several distinct units, to which
the U.S. Geological Survey assigns member rank. Baars (1962), however, assigned these units
formation rank and the Cutler, group rank, in southeastern Utah. A sequence of carbonate and clastic

" rocks that grades into the lowermost shaly beds of the Cutler was designated by Baars (1962) as the
“hoo White Rim Zs Elephant Canyon Formation. The nomenclature of Baars (1962) regarding the Cutler rocks is used
Hf — ,- Coconino Sandsto! 3 it ai ae = in thi
PERMIAN Leonardian Sandstone — - nino sendsione 3g eee = a ss Csaotan. 3 Weber-De Chelly zone 4,000 annihisiCeeale:
Early or ss S| 2 | Hunters Pont Mor} 5 12. Cambrian units cropping out in the Grand Canyon, the Tapeats Sandstone, Bright Angel Shale,
il a whee in | | 1 = SS | ? and Muav Limestone, were traced during this study into northeastern Arizona and southwestern
ower "e enicstone: | | Colorado by means of borehole lithologic logs. Because no names for the shale and carbonate
é —— 7 Covet ieee | | Cutler Formation Cutler Formation units currently are recognized by the U.S. Geological Survey in Colorado, the names "Bright
Wolfcampian - 4 Weber Sandstone : cerenete) Supai Formation " 7 : 5 Angel equivalent" and “Muav equivalent" were used beyond the Grand Canyon area where
Weber Sandstone Seipomiouws Monet ren el of —— a 3 S | Sandstone | rocks characteristic of the Bright Angel Shale and Muav Limestone, respectively, were identified.
' | SOE OOD OFTEN | } ‘cine, ae , An equivalent of the Tapeats Sandstone crops out in the San Juan Mountains of Colorado, where
Li ; —— i > —__— — — Cutler-Maroon zone itis called the Ignacio Quartzite. In this report, an axis of thinning in southwestern Colorado was
Virgilian = | aR gen a) : H - a Rico Formation Rico Formation ’ 16,500 considered the boundary between the extension of the Tapeats Sandstone beyond the Grand
Late or Wells Merson! : - = Maréon Formation. —— ————_— —= o bal | | Canyon area, the "Tapeats equivalent," and the Ignacio Quartzite. As shown by Baars (1983, p. 54),
Upper Missourian Formation Tensleep Tensleep | a } 3 ‘upper member 7 | the Cambrian geologic units become progressively younger from the Grand Canyon to the San Juan
Sandstone Sepssione ra = | upper member upper member r a : upper member ‘upper member Mountains. Hence, in the Defiance Plateau and Four Corners platform columns, the ages of the Tapeats
D . . = = [ * - a | ee - a i equivalent, Ignacio Quartzite, Bright Angel equivalent, and Muav equivalent are depicted as intermediate
PENNSYLVANIAN Middle esmolinesian ney " : 7 = = between ages in outcrop areas to the west and east.
Atokan | | Ranchester - 13. Excluding salt diapirs of small areal extent that can be as much as 15,000 feet thick.
T
Early or Morrowan =| L J . 14. Although Precambrian rocks do not crop out and have not been penetrated by boreholes in the
Lower L Overthrust Belt within the Upper Colorado River Basin, Archean granitic and metamorphic rocks
. are exposed in the Farmington complex, about 30 miles west of the Utah-Wyoming State line
Late or Chesterian (Bryant, 1988).
Upper__|"Meramecian
[S}
fe) MISSISSIPPIAN Osagean
N
(S) Early or
w Lower 7
z Kinderhookian :
a ti Cottonwood Cottonwood
Canyon Member Canyon Member
Late or nant Temple Butte
DEVONIAN Upper ees Formation Parting Formation Parting Formation Parting Formation Elbert Formation Elbert Formation Elbert Formation Elbert Formation Formation Elbert Formation Elbert Formation Elbert Formation Elbert-Parting confining unit 700
Early or
Lower
SILURIAN
Late or
Upper
ORDOVICIAN Middle
Early or

Lower

Late or

Upper '

Sawatch Quartzite Be Srey Sawatch Quartzite
V,
Flathead "
CAMBRIAN ebndicre Lodore Formation8 Ignacio Quartzite .
. Flathead aquifer 800
Middle Flathead V4 3 Tapeats 2.
Sandstone Y Tintic Quartzite = equivalent "4
Flathead intic Quartzite inti it Tapeats
Sandstone 4 Tintic Quartzite Tintic Quartzite sree
7 “ 7
Early or Y Y WY Y
Lower
2
fe)
2s
Ag
°
a :
Not discussed
in in thi rt.
Red Pine Shale Chuar Group Basal icant) (See Hedge and
z 5 Nankoweap Fm others, 1986)
< g ui '
(we @N Uinta Mountain inta Mountain Unkar Group Yj
38 ge Group Group Y
= 20
i ShkemGrne: Slightly metamorphosed
& ‘sedimentary and Gnecmnpatiore 2
” 2 Granitic and A Granitic and Granitic and Zoeseter volcanic rocks mation
>Oy metamorphic ne Tee Te metamorphic Granitic rocks Granitic rocks Complex Granitic and Granitic and Granitic and
moe ks (7, ; i ; i
He 2 Key) rocks ae Metamorphic rocks Vishnu Schist metarrerphic metamorc mnetemrorphio
3} g Granitic and Granitic and Granitic and Red Creek
GE metamorphic metamorphic metamorphic Quartzite
“§ rocks (2) 14 rocks (?) rocks (?)