Koley Black group (Cold Mesa; Channel No. 37), Agathla Peak (El Capitan), Mineral Mining District, Navajo Co., Arizona, USAi
|Regional Level Types|
|Koley Black group (Cold Mesa; Channel No. 37)||- not defined -|
|Agathla Peak (El Capitan)||Peak|
|Mineral Mining District||Mining District|
A group of claims located about 6.7 km (4.2 miles) ESE of Agathla Peak (coordinates of record), and about 8 miles NE of Kayenta covering channels (paleochannels) No. 37 through 47 in the USGS 15 minute Keams Canyon quadrangle. Coordinates provided are for the approximate center of the group.
Mineralization occurs in paleochannels that trend N35W at 80 to 100 feet wide and 25 feet deep, and comprised of coarse-grained, lenticular sandstone.
The Koley Black area, at lat 36°48'12" N., and long 110°09'18" W., is in Navajo County, Ariz., about 3 miles southeast of Agathla Peak and a similar distance due north of the Porras Dikes. The area is about 8 miles northeast of Kayenta, Ariz. Consolidated sedimentary strata exposed in the Koley Black area range from the De Chelly sandstone member of the Cutler formation, under the valley floors, to the Shinarump member of the Chinle formation, which forms the general upland surface. The Shinarump member in this area is about 25 feet thick, although it thickens to 45 feet or more as a result of channeling. In places on the upland surface the Shinarump member thins laterally as a result of erosion; in these localities the underlying Moenkopi formation forms the surface.
The ground surface is veneered by a thin mantle of sand that thickens locally to 5 feet or slightly more. In places, irregular hummocks of the Shinarump member rise 20 to 30 feet above the general ground surface.The area is on the south flank of the Agathla anticline, and the strata dip about 5° to the south.
A maze of channels is exposed in this area. They range in width from channels 35 feet wide to others that exceed 250 feet in width. The major geologic problem, as shown in figure 12, has been to relate the 4 channels noted in the southeastern part of the area to the 7 channels in the north western part. Data on the channels are given in table 1. All the channels strike northwest, and this suggests that they all may be part of the same channel network. In general, the larger channels are in the southeastern part of the area, and it appears probable that one or more of these larger ones may have branched to form the smaller channels.
Sedimentary rocks filling the channels are coarse conglomerate beds near the base which grade upward into conglomeratic sandstone and coarse-grained sandstone beds near the top. Silicified wood is buried in channel strata as fragments and as logs as much as 2 feet in diameter. Also included are small pod-shaped masses of a black, coaly substance (vitrain?) surrounded by conglomeratic sandstone. Limonite stains the surface of the channel fill but does not appear to have penetrated the sandstone.
The Koley Black channels are underlain by a green to light-gray altered zone about 1 foot thick in the uppermost siltstone beds of the Moenkopi. The altered zone thickens slightly below the channels. Four of the Koley Black group of channels contain small amounts of copper in basal channel fill.
Regions containing this locality
|North America Plate||Tectonic Plate|
|Colorado Plateau, USA||Plateau|
|Navajo Nation Indian Reservation, USA||Reservation|
|Hopi-Navajo Indian Reservations, Colorado Plateau, Apache; Navajo and San Juan Cos., Arizona & Utah, USA|
Select Mineral List TypeStandard Detailed Strunz Dana Chemical Elements
Commodity ListThis is a list of exploitable or exploited mineral commodities recorded from this region.
Mineral ListMineral list contains entries from the region specified including sub-localities
6 valid minerals.
Rock Types Recorded
Rock list contains entries from the region specified including sub-localities
Select Rock List TypeAlphabetical List Tree Diagram
Detailed Mineral List:
List of minerals arranged by Strunz 10th Edition classification
|Group 4 - Oxides and Hydroxides|
|ⓘ||Tyuyamunite||4.HB.25||Ca(UO2)2(VO4)2 · 5-8H2O|
|Group 5 - Nitrates and Carbonates|
|Group 7 - Sulphates, Chromates, Molybdates and Tungstates|
|Group 9 - Silicates|
|Unclassified Minerals, Rocks, etc.|
List of minerals arranged by Dana 8th Edition classification
|Group 14 - ANHYDROUS NORMAL CARBONATES|
|Group 16a - ANHYDROUS CARBONATES CONTAINING HYDROXYL OR HALOGEN|
|Group 30 - ANHYDROUS SULFATES CONTAINING HYDROXYL OR HALOGEN|
|Group 40 - HYDRATED NORMAL PHOSPHATES,ARSENATES AND VANADATES|
|AB2(XO4)2·xH2O, containing (UO2)2+|
|ⓘ||Tyuyamunite||40.2a.26.1||Ca(UO2)2(VO4)2 · 5-8H2O|
|Group 71 - PHYLLOSILICATES Sheets of Six-Membered Rings|
|Sheets of 6-membered rings with 2:1 layers|
|Unclassified Minerals, Mixtures, etc.|
List of minerals for each chemical element
|H||ⓘ Jarosite||KFe3+ 3(SO4)2(OH)6|
|H||ⓘ Tyuyamunite||Ca(UO2)2(VO4)2 · 5-8H2O|
|O||ⓘ Jarosite||KFe3+ 3(SO4)2(OH)6|
|O||ⓘ Tyuyamunite||Ca(UO2)2(VO4)2 · 5-8H2O|
|S||ⓘ Jarosite||KFe3+ 3(SO4)2(OH)6|
|K||ⓘ Jarosite||KFe3+ 3(SO4)2(OH)6|
|Ca||ⓘ Tyuyamunite||Ca(UO2)2(VO4)2 · 5-8H2O|
|V||ⓘ Tyuyamunite||Ca(UO2)2(VO4)2 · 5-8H2O|
|Fe||ⓘ Jarosite||KFe3+ 3(SO4)2(OH)6|
|U||ⓘ Tyuyamunite||Ca(UO2)2(VO4)2 · 5-8H2O|
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. 
|Norian - Carnian|
208.5 - 237 Ma
Age: Late Triassic (208.5 - 237 Ma)
Stratigraphic Name: Chinle Formation
Description: Colorful mudstone, such as in the Painted Desert, and less abundant lenses of sandstone and conglomerate, deposited by a large river system. This unit typically is eroded into badlands topography and contains clays that are prone to shrinking and swelling. (210-230 Ma)
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. 
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Localities in this RegionShow map
- Navajo Co.
- Mineral Mining District
- Agathla Peak (El Capitan)
- Koley Black group (Cold Mesa; Channel No. 37)
- Agathla Peak (El Capitan)
- Mineral Mining District
- Navajo Co.