| Deposit ID | 10101864 |
|---|---|
| MRDS ID | D010723 |
| Record type | Site |
| Current site name | Little May Mine |
| Related records | 10239936 |
| Geographic coordinates: | -107.5348, 37.71612 (WGS84) |
|---|---|
| Elevation | 3694 |
| Relative position | 9.1 MILES S 47 E FROM SILVERTON |
Political divisions (FIPS codes)
San Juan(county)
Colorado(state)
United States(country)
North America(continent)
Land(continent)
USGS map quadrangles
Storm King Peak(quadrangle 1:24,000 scale)
Silverton(quadrangle 1:100,000 scale)
Durango(quadrangle 1:250,000 scale)
Hydrologic units (watersheds)
Rio Grande Headwaters(hydrologic unit)
Rio Grande Headwaters(hydrologic accounting unit)
Rio Grande Headwaters(hydrologic subregion)
Rio Grande(hydrologic region)
Federal lands
Rio Grande National Forest(National Forest)
National Forest FS(Type of land area)
FS(Federal land areas administered by FS)
| Country | State | County |
|---|---|---|
| United States | Colorado | San Juan |
| Meridian | Township | Range | Section | Fraction | State |
|---|---|---|---|---|---|
| New Mexico | 040N | 006W | 20 | SE | Colorado |
| Commodity | Importance |
|---|---|
| Gold | Primary |
| Silver | Primary |
| Copper | Secondary |
| Lead | Secondary |
| Zinc Critical | Tertiary |
| Tellurium Critical | Tertiary |
| Antimony Critical | Tertiary |
| Materials | Type of material |
|---|---|
| Bornite | Ore |
| Calaverite | Ore |
| Chalcocite | Ore |
| Chalcopyrite | Ore |
| Galena | Ore |
| Marcasite | Ore |
| Petzite | Ore |
| Sphalerite | Ore |
| Sylvanite | Ore |
| Tetrahedrite | Ore |
| Barite | Gangue |
| Calcite | Gangue |
| Hematite | Gangue |
| Limonite | Gangue |
| Quartz | Gangue |
| Result | STEVEN AND OTHERS' (1969) SEMIQUANTITATIVE SPECTROGRAPHIC ANALYSES OF PYRITE-BEARING SHEARED ZONE SHOWED 300 TO 1000 PPM TI, 30 TO 70 PPM MN, 1.5 TO 5 PPM AG, 700 PPM AS, 100 TO 300 PPM BA, LT 10 PPM BI, LT 20 PPM CD, LT 5 TO 7 PPM CO, LT 5 TO 5 PPM CR, 7 TO 30 PPM CU, LT 5 PPM MO, 20 TO 100 PPM NI, 15 TO 20 PPM PB, LT 100 PPM SB, LT 10 PPM SN, LT 100 TO 100 PPM SR, LT 10 TO 15 PPM V, LT 50 PPM W, LT 200 PPM ZN, 7 TO 15 PPM FE. CHEMICAL ANALYSES SHOWED LT 0.02 PPM AU, LT 10 PPM CU, LT 25 PPM PB, 28 TO 38 PPM ZN, 4 TO 8 PPM MO, 30 PPM AS, 8 PPM SB, 1.3 PPM HG, 0.3 PPM TE, LT 0.1 PPM AG. |
|---|
| Model code | 84 |
|---|---|
| USGS model code | 22b |
| Deposit model name | Alkaline Au-Te (Au-Ag-Te veins) |
| Mark3 model number | 80 |
| Host or associated | Associated | ||||||
|---|---|---|---|---|---|---|---|
| Rock type | Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Rhyodacite | ||||||
| |||||||
| Host or associated | Associated |
|---|---|
| Rock type | Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Quartz Latite |
| Host or associated | Associated |
|---|---|
| Rock type | Volcanic Rock (Aphanitic) > Intermediate Volcanic Rock > Andesite |
| Rock unit name | San Juan Formation;Early Intermediate Lavas And Breccias--Near-Source Facies |
| Rock description | San Juan Formation;Early Intermediate Lavas And Breccias--Near-Source Facies |
| Host or associated | Host |
|---|---|
| Rock type | Metamorphic Rock > Metasedimentary Rock > Slate |
| Host or associated | Host |
|---|---|
| Rock type | Metamorphic Rock > Metasedimentary Rock > Quartzite |
| Rock unit name | Uncompahgre Formation |
| Rock description | Uncompahgre Formation |
| Host or associated | Host |
|---|---|
| Rock type | Sedimentary Rock > Clastic Sedimentary Rock > Argillite |
| (1) | Pre-ash-flow andesitic lavas, breccias, tuffs, and conglomerates |
|---|
| Type of structure | Regional |
|---|---|
| Structure description | San Juan Uplift, San Juan Volcanic Field |
| Type of structure | Local |
| Structure description | San Juan Uplift, Unnamed Fault |
| Development status | Past Producer |
|---|---|
| Commodity type | Metallic |
| Deposit size | Small |
| Significant | No |
| Discovery year | 1892 |
| Year of first production | 1893 |
| District name | Beartown (Bear Creek) District |
|---|
| Ownership category | National Forest |
|---|---|
| Area name | San Juan N. F. |
| Agency | Database name | Acronym | Record ID | Notes |
|---|---|---|---|---|
| USGS | Mineral Resources Data System | MRDS | D010723 | |
| U.S. Bureau of Mines | Minerals Availability System | MAS | 0081110262 |
STEVEN, T.A., AND OTHERS, 1969, MINERAL RESOURCES OF THE SAN JUAN PRIMITIVE AREA, COLORADO: USGS BULL. 1261-F, P. 67-71, 89-90, 168-171.
STEVEN, T.A., AND OTHERS, 1974, GEOLOGIC MAP OF THE DURANGO QUADRANGLE, SOUTHWESTERN COLORADO: USGS MAP I-764.
CROSS, WHITMAN, AND OTHERS, 1905, DESCRIPTION OF THE NEEDLE MOUNTAINS QUADRANGLE, COLORADO: USGS FOLIO 131.
PROSSER, W.C., 1911, THE BEAR CREEK SYLVANITE CAMP, COLORADO: ENG. MINING JOUR., V. 91, P. 712.
| Subject category | Comment text |
|---|---|
| Deposit | MINE DEVELOPED ON WNW-TRENDING QUARTZ VEIN WEST OF CENTRALLY CONCENTRATED FISSURE ZONE AND WEST OF SMALLER CONCENTRATED ZONE ON CONTINENTAL DIVIDE AT SUMMIT AND GOLDEN SHEAR MINES. VEIN TREND IS AT APPROX RIGHT ANGLE TO PREDOMINANT NNE TREND IN REST OF DISTRICT TO EAST. VEIN LIES ALONG EAST-WEST-TRENDING FAULTS ENCLOSING NARROW BAND OF SLATE AND ARGILLITE BETWEEN QUARTZITE. |
| Type | Date | Name | Affiliation | Comment |
|---|---|---|---|---|
| Reporter | 01-JUL-1983 | Schwochow, Stephen D. | Colorado Geological Survey |
Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.
These are landing pages for further research — the state agencies don't currently expose per-mine deep links.