A gypsum occurrence/mine located in the N½ sec. 15, T19N, R15E, G&SRM, 4.9 km (3.1 miles) WNW of Winslow, on state owned land.
Local rocks include rocks of the Moenkopi Formation.
Workings include unspecified surface openings.
Regions containing this locality
|North America Plate||Tectonic Plate|
|Colorado Plateau, USA||Plateau|
Select Mineral List TypeStandard Detailed Strunz Dana Chemical Elements
Commodity ListThis is a list of exploitable or exploited mineral commodities recorded at this locality.
1 valid mineral.
Detailed Mineral List:
| ⓘ Gypsum|
Formula: CaSO4 · 2H2O
Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, deposit ID #10234327.
List of minerals arranged by Strunz 10th Edition classification
|Group 7 - Sulphates, Chromates, Molybdates and Tungstates|
|ⓘ||Gypsum||7.CD.40||CaSO4 · 2H2O|
List of minerals arranged by Dana 8th Edition classification
|Group 29 - HYDRATED ACID AND NORMAL SULFATES|
|ⓘ||Gypsum||22.214.171.124||CaSO4 · 2H2O|
List of minerals for each chemical element
|H||ⓘ Gypsum||CaSO4 · 2H2O|
|O||ⓘ Gypsum||CaSO4 · 2H2O|
|S||ⓘ Gypsum||CaSO4 · 2H2O|
|Ca||ⓘ Gypsum||CaSO4 · 2H2O|
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
|Early Jurassic - Late Triassic|
174.1 - 237 Ma
|Mesozoic sedimentary rocks|
Age: Mesozoic (174.1 - 237 Ma)
Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. 
|Carnian - Anisian|
227 - 247.2 Ma
Age: Triassic (227 - 247.2 Ma)
Stratigraphic Name: Moenkopi Formation
Comments: Original map source: Arizona Geological Survey, DI-8 Geologic Map of Arizona, Digital Spatial data for the Geologic Map of Arizona, v. 3.0, edited by S.M. Richard and S.M. Kneale, 2002, 10 p., 2 DOS HD disks. Arc/INFO export file (.e00) format, scale 1:1,000,000.
Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. 
|Middle Triassic - Early Triassic|
237 - 251.902 Ma
|Holbrook and Moqui Members, undivided|
Age: Triassic (237 - 251.902 Ma)
Stratigraphic Name: Holbrook Member; Moqui Member
Description: Reddish-brown, slope-forming, alternating sequence of claystone, siltstone, and sandstone (McKee, 1954). Includes large- to medium-scale trough-crossbedding and abundant cusp-type ripple marks that testify to isolated fluvial-channel origin of the Holbrook Member; meander channels of the Holbrook Member are easy to recognize on 1:24,000-scale color aerial photographs between Winslow and Leupp. Commonly also includes sandstone and siltstone beds of the Moqui Member, making it an undivided map unit. Includes interbedded thin-bedded limestone, conglomeratic sandstone lenses, and gypsiferous siltstone and numerous gypsum veins in the Moqui Member. Thickness, about 25 to 37 m (80 to 120 ft)
Comments: Moenkopi Formation (Middle? and Lower Triassic)—Red, slope-forming, fine-grained, thin-bedded, shaley siltstone and sandstone. Includes the following two subunits, in ascending order: the lower massive sandstone member, and the undivided Holbrook and Moqui Members. The lower massive sandstone member also includes the Wupatki Member of the Moenkopi Formation (McKee, 1954) because it generally is less than 4.5 m (15 ft) thick and pinches out in southwest quarter of quadrangle just west of Winslow (sheet 1). Overall, unit has unconformable contact with the underlying Kaibab Formation (Pk), representing regional Permian–Triassic unconformity. Thickness, 67 m (220 ft)
Reference: Billingsley, G.H., D. Block, and M. Hiza Redsteer. Geologic map of the Winslow 30’ × 60’ quadrangle, Coconino and Navajo Counties, northern Arizona. U.S. Geological Survey Scientific Investigations Map 3247.