| Deposit ID | 10014081 |
|---|---|
| MRDS ID | D010704 |
| Record type | Site |
| Current site name | Chicago Basin Disseminated Molybdenum Deposit |
| Geographic coordinates: | -107.61202, 37.60362 (WGS84) |
|---|---|
| Elevation | 3505 |
| Relative position | 14.3 MILES S 11 E FROM SILVERTON |
Political divisions (FIPS codes)
La Plata(county)
Colorado(state)
United States(country)
North America(continent)
Land(continent)
USGS map quadrangles
Columbine Pass(quadrangle 1:24,000 scale)
Silverton(quadrangle 1:100,000 scale)
Durango(quadrangle 1:250,000 scale)
Hydrologic units (watersheds)
Animas(hydrologic unit)
Upper San Juan(hydrologic accounting unit)
San Juan(hydrologic subregion)
Upper Colorado(hydrologic region)
Federal lands
San Juan National Forest(National Forest)
National Forest FS(Type of land area)
FS(Federal land areas administered by FS)
Weminuche Wilderness(Wilderness)
Wilderness FS(Type of land area)
FS(Federal land areas administered by FS)
| Country | State | County |
|---|---|---|
| United States | Colorado | La Plata |
| Meridian | Township | Range | Section | Fraction | State |
|---|---|---|---|---|---|
| New Mexico | 039N | 007W | 34,35 | Colorado |
| Commodity | Importance |
|---|---|
| Molybdenum | Primary |
| Copper | Secondary |
| Lead | Secondary |
| Zinc Critical | Secondary |
| Manganese Critical | Tertiary |
| Materials | Type of material |
|---|---|
| Chalcopyrite | Ore |
| Galena | Ore |
| Molybdenite | Ore |
| Pyrite | Ore |
| Sphalerite | Ore |
| Tetrahedrite | Ore |
| Dickite | Gangue |
| Kaolinite | Gangue |
| Pyrophyllite | Gangue |
| Quartz | Gangue |
| Rhodochrosite | Gangue |
| Sericite | Gangue |
| Result | SCHMITT AND RAYMONDS RAPID ROCK ANALYSES OF 4 SAMPLES OF LEAST ALTERED OLDER PORPHYRY: 76.4 TO 78.2% SIO2, 11.5 TO 12.5% AL203, 0.06 TO 0.39% FE203, 0.12 TO 0.28% FEO, 0.06 TO 0.15% MGO, 0.02 TO 0.18% CAO, 1.0 TO 2.8% NA2O, 6.3 TO 7.3% K20, 0 TO 0.17% H2O-, 0.63 TO 1.8% H2O+, 0.12 TO 0.15% TIO2, 0 P2O5, 0 TO 0.02% MNO, LT 0.05 TO 0.06% CO2. |
|---|---|
| Result | SIX SAMPLES OF ALTERED OLDER PORPHYRITIC ROCK: 78.4 TO 79.9% SIO2, 11.9 TO 13.6% AL2O3, 0.14 TO 0.94% FE2O3, 0.12 TO 0.40% FEO, 0.12 TO 0.55% MGO, 0.07 TO 0.61% CAO, 0.03 TO 0.37% NA2O, 3.2 TO 4.0% K2O, 0.02 TO 0.12% H2O-, 1.7 TO 2.6% H2O+, 0.13 TO 0.22% TIO2, 0 TO 0.05% P2O5, 0 TO 0.04% MNO, LT 0.05 TO 0.05% CO2. |
| Result | FOUR SAMPLES OF ALTERED OLDER BRECCIATED ROCK:76.2 TO 80.3% SIO2, 12.0 TO 14.4% AL2O3, 0.47 TO 2.4% FE2O3, 0.12 TO 0..36% FEO, 0.06 TO 0.55% MGO, 0.09 TO 0.43% CAO, 0.05 TO 0.16% NA2O, 0.61 TO 4.0% K2O, 0.05 TO 0.25% H2O-, 1.6 TO 2.7% H2O+, 0.27 TO 0.41% TIO2, 0.06 TO 0.15% P2O5, 0 TO 0.04% MNO, LT 0.05 TO 0.05% CO2. |
| Result | TWO SAMPLE S OF LEAST ALTERED YOUNGER PORPHYRY: 73.5 TO 74.3% SIO2, 13.6 TO 14.2% AL2O3, 1 TO 1.1% FE2O3, 0.32 TO 0.40% FEO, 0.18 TO 0.31% MGO, 0.30 TO 0.40% CAO, 2.3 TO 2.4% NA2O, 5.1 TO 5.2% K2O, 0.29 TO 0.51% H2O-, 1.3 TO 1.5% H20+, 0.24 TO 0.27% TIO2, 0.03 TO 0.06% P2O5, 0.02 TO 0.05% MNO, LT 0.05 TO 0.08% CO2. |
| Result | ONE SAMPLE OF ALTERED YOUNGER PORPHYRY: 77.8% SIO2, 14.0% AL2O3, 0% FE2O3, 0.45% FEO, 0.21% MGO, 0.10% CAO, 0.04% NA2O, 2.6% K2O, 0.19% H2O-, 3.5% H2O+, 0.30% TIO2, 0.02% P2O5, 0% MNO, 0.05% CO2. |
| Model code | 50 |
|---|---|
| USGS model code | 16 |
| Deposit model name | Climax Mo |
| Host or associated | Associated | ||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rock type | Plutonic Rock > Granitoid > Quartz Monzonite | ||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||
| Host or associated | Associated | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rock type | Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Rhyolite | ||||||||||||
| |||||||||||||
| Host or associated | Associated | ||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rock type | Plutonic Rock > Granitoid > Granite | ||||||||||||||||||||||||||||||||
| Rock unit name | Intrusive Bodies And Related Rocks (Younger And Older Bodies Of Chicago Basin Stock);Eolus Granite | ||||||||||||||||||||||||||||||||
| Rock description | Intrusive Bodies And Related Rocks (Younger And Older Bodies Of Chicago Basin Stock);Eolus Granite | ||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||
| Host or associated | Host | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rock type | Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Rhyolite | ||||||||||||
| |||||||||||||
| Host or associated | Host | ||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rock type | Plutonic Rock > Granitoid > Granite | ||||||||||||||||||||||||||||||||
| Rock unit name | Intrusive Bodies And Related Rocks (Younger And Older Bodies Of Chicago Basin Stock) | ||||||||||||||||||||||||||||||||
| Rock description | Intrusive Bodies And Related Rocks (Younger And Older Bodies Of Chicago Basin Stock) | ||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||
| (1) | -107.61202, 37.60362 |
|---|
| Type of structure | Regional |
|---|---|
| Structure description | San Juan Uplift, San Juan Basin, San Juan Volcanic Field |
| Type of structure | Local |
| Structure description | Needle Mtns Uplift, Chicago Basin Stock, Eolus Batholith, Trimble Stock |
| Development status | Occurrence |
|---|---|
| Commodity type | Metallic |
| Deposit size | Small |
| Significant | No |
| District name | Needle Mountain (Tacoma, Florida, Vallecito) District |
|---|
| Ownership category | National Forest |
|---|---|
| Area name | San Juan N. F. |
| Agency | Database name | Acronym | Record ID | Notes |
|---|---|---|---|---|
| USGS | Mineral Resources Data System | MRDS | D010704 |
SCHMITT, L.J., AND RAYMOND, W.H., 1977, GEOLOGY AND MINERAL DEPOSITSOF THE NEEDLE MOUNTAINS DISTRICT, SOUTHWESTERN COLORADO: USGS BULL. 1434, 40 P.
| Subject category | Comment text |
|---|---|
| Deposit | CHICAGO BASIN STOCK IS COMPOSITE, HYPABYSSAL INTRUSIVE OF SILICIC TO INETERMEDIATE COMPOSITION INTRUDING WESTERN LOBE OF EOLUS GRANITE BATHOLITH. SUBCIRCULAR, OLDER OUTER PORTION IS GRANITE (OR QUARTZ) PORPHYRY INTENSELY ALTERED TO QUARTZ-SERICITE-KAOLINITE AND KAOLINITE-DICKITE-PYROPHYLLITE AND IS CHARACTERIZED BY DISSEMINATED PYRITE, WITH MO IN VEINLETS AND DISSEMINATED IN POCKETS OF ALTERATION MINERALS AND THROUGH GROUNDMASS OF PORPHYRITIC ROCKS. ELLIPTICAL, INNER YOUNGER INTRUSIVE PHASE (RHYOLITE PORPHYRY) IS LESS INTENSELY ALTERED. BOTH PORPHYRIES ARE CUT BY LATER MAFIC DIKES. GEOCHEMICAL SAMPLING SHOWED WESTERN SIDE OF OLDER BODY ANOMALOUS IN AS, SB, CU, BI, AU, PB, MO, AND SN. K2O AND NA2O DEPLETED DURING FELDSPAR REPLACEMENT BY SERICITE AND NEARLY ELIMINATED DURING SERICITE REPLACEMENT BY PYROPHYLLITE. GEOCHEMICAL SAMPLING OF YOUNGER BODY SHOWS WEAK SCATTERED ANOMALIES IN MO, AG, PB, AND ZN, WITH TWO SAMPLES DETECTING BI AND SN. OUTER MARGIN HAS SOMEWHAT HIGHER METAL CONTENT |
| Deposit | THAN CENTER: RELATIVE ENRICHMENT OF SIO2 AND H2O AND RELATIVE DEPLETION OF FE2O3, CAO, NA2O, AND K2O. LEAST ALTERED SAMPLES OF YOUNGER PORPHYRY PLOT BETWEEN LEAST ALTERED OLDER PORPHYRY AND SERICITIZED OLDER PORPHYRY. SCHMITT AND RAYMOND MAP ANOMALOUS AREAS ON BASIS OF GEOCHEMICAL SAMPLING. BEYOND STOCK IS GENERAL TRIANGULAR AREA OF ALTERATIONEXTENDING FROM STOCK EAST TO JUPITER PEAK AND SW TO AZTEC MTN. PRINCIPAAL BI-SN ANOMALY LIES IN VALLECITO BASIN, ALONG WITH ANOMALOUS AG, CU, AS, AND SB. MO ANOMALY EXTENDS NORTH FROM MT EOLUS MINE AREA IN UPPER CHICAGO BASIN, SE THROUGH STOCK AND ALTERED AREA, THROUGH VALLECITO BASIN, AZTEC, BULLION, AND FLORIDA MTNS, LILLIE LAKE, AND ACROSS NORTH HALF OF EAST SILVER MESA. EAST-WEST BOUNDARIES ARE ZONE OF PRINCIPAL MINERALIZED RADIAL FRACTURES AND CONCENTRATION OF REGIONAL RECTANGULAR FRACTURES IN VALLECITO BASIN AND AT NORTH END OF EAST SILVER MESA, AND ESPECIALLY AT INTERSECTIONS OF TWO SYSTEMS. SECOND MO ANOMALY NOTED AROUND NORTH-TRENDING |
| Deposit | VEINS NORTH OF LOGTOWN AND EAST OF CRYSTAL VALLEY. |
| 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.
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