| Deposit ID | 10165203 |
|---|---|
| MRDS ID | W025015 |
| MAS/MILS ID | 0060790028 |
| Record type | Site |
| Current site name | Castro Mine |
| Alternate or previous names | Castro Chrome Mine |
| Related records | 10077401 |
| Point of reference | Trench |
|---|---|
| Geographic coordinates: | -120.70847, 35.37357 (WGS84) |
| Elevation | 488 |
| Location accuracy | 10(meters) |
Political divisions (FIPS codes)
San Luis Obispo(county)
California(state)
United States(country)
North America(continent)
Land(continent)
USGS map quadrangles
San Luis Obispo(quadrangle 1:24,000 scale)
San Luis Obispo(quadrangle 1:100,000 scale)
San Luis Obispo(quadrangle 1:250,000 scale)
Hydrologic units (watersheds)
Central Coastal(hydrologic unit)
Central California Coastal(hydrologic accounting unit)
Central California Coastal(hydrologic subregion)
California(hydrologic region)
Federal lands
Los Padres National Forest(National Forest)
National Forest FS(Type of land area)
FS(Federal land areas administered by FS)
| Country | State | County |
|---|---|---|
| United States | California | San Luis Obispo |
| Meridian | Township | Range | Section | Fraction | State |
|---|---|---|---|---|---|
| Mount Diablo | 029 S | 012 E | 29 | NWNWSE | California |
| Commodity | Importance |
|---|---|
| Chromium Critical | Primary |
| Materials | Type of material |
|---|---|
| Chromite | Unknown |
| Magnesite | Unknown |
| Magnetite | Unknown |
| Serpentine | Unknown |
| Talc | Unknown |
| Trench (1) | -120.70847, 35.37357 |
|---|
| Dip | 00N | ||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Thickness | 5M | ||||||||||||||||||||||||||||||||||||||
| Length | 30M | ||||||||||||||||||||||||||||||||||||||
| Width | 0M | ||||||||||||||||||||||||||||||||||||||
| Area | 7.3HA | ||||||||||||||||||||||||||||||||||||||
| Depth to top | 10M | ||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||
| Operation type | Surface |
|---|---|
| Development status | Past Producer |
| Commodity type | Metallic |
| Significant | No |
| Discovery year | 1876 |
| Year of first production | 1918 |
| District name | Questa Pass |
|---|
| Type of mineral rights | Patented |
|---|
| Ownership category | Private |
|---|
| Type | Owner |
|---|---|
| Owner | Castro Chrome Associates-Last Operators |
| Year | 1976 |
| First year | 1953 |
| Last year | 1957 |
| Type | Owner |
|---|---|
| Owner | Ernest Vallmer Jr. |
| Interest | 100 |
| Home office | California |
| Year | 1976 |
| Year | 1917 | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Description | Concentrates Produced From 1917-1919 3150 Metric Tons @ 40 Pct | ||||||||||||||
| |||||||||||||||
| Year | 1933 | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Description | Concentrates Produced 80 Metric Tons | ||||||||||||||
| |||||||||||||||
| Year | 1942 | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Description | Concentrates Produced From 1942-1944 2550 Mt @ 42 Pct-2.7:1 Cr:Fe | ||||||||||||||
| |||||||||||||||
| Year | 1953 | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Description | Concentrates Produced From 1953-1957 15100 Mt @ 42 Pct-2.4:1 Cr:Fe | ||||||||||||||
| |||||||||||||||
| Agency | Database name | Acronym | Record ID | Notes |
|---|---|---|---|---|
| U.S. Bureau of Mines | Minerals Availability System | MAS | 0060790028 | |
| USGS | Mineral Resources Data System | MRDS | W025015 | MAS references MRDS |
CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD, CENTRAL
COAST REGION. SURFACE WATER DEGRADATION BY INACTIVE
METAL MINES IN NORTHWEST SAN LUIS OBISPO COUNTY, CA,
DECEMBER 1993 (P. 6-8).
CALIF. STATE MINING BUR. BULLETIN 76, 1918, P. 167-169.
CALIF. FOUR. MINES AND GEOL V. 37, 1941, P. 141, 161.
U.S. GEOLOGICAL SURVEY BULLETIN 945-B, 1944, P. 34-37.
U.S. BUREAU OF MINES RI 4783, 1951, P. 4-5.
CALIF. DIV. MINES BULLETIN 134, 1953, PART II, CHAPT. 2,
P. 60-61.
| Subject category | Comment text |
|---|---|
| Deposit | CALCULATED AVERAGE GRADE OF 15111 LONG TONS SHIPPED IN 1953-1 .65 % CR2O3, 12.24%FE,2.32 TO 1 CR/FE RATIO. TOTAL PRODUCTION ESTIMATED TO BE OVER 111,168 LONG TONS OF 2 3. LOW PROBABILTY OF DISCOVERING NEW RESERVES BECAUSE OF EXT PAST EXPLORATION. INSUFFICIENT DATA FOR MATRIX CALCULATIONS. ANALYSIS BY CDMG IN 1976 GAVE FOLLOWING PERCENTAGES-DISSEMIN E=SI02 08.00,CR2O3 45.31,FEO 08.82,TOTAL FE 12.87,AL203 13.2 7.83,CR/FE 3.10. FE 11.67,AL203 12.99,MGO 20.48,CR/FE 2.69.BANDED ORE=S102 21 03 29.23,FEO 9.39,TOTAL FE 12.07,AL203 11.81,MGO 23.14,CR/FE |
| Environmental Factors | CHROMITE DEPOSITS IN THE CHORRO CREEK WATERSHED ARE NOT SULFIDES WITH POTENTIAL TO GENERATE ACID MINE DRAINAGE THOUGH THEY MAY ERODE CHROMIUM, ALUMINU, MAGNESIUM, IRON, MANGANESE, TITANIUM, CALCIUM, SILICON, AND NICKEL TO THE WATERSHED. METALS WHICH APPEAR TO BE ERODING FROM INACTIVE MINES INCLUDE MANGESIUM, IRON, NICKEL, AND CHROMIUM. SAN LUISITO CREEK, PENNINGTON CREEK, AND UPPER CHORRO CREEK APPEAR TO BE THE MOST HEAVILY MINE-IMPACTED TRIBUTARIES IN THE CHORRO CREEK WATERSHED. |
| Type | Date | Name | Affiliation | Comment |
|---|---|---|---|---|
| Reporter | 05-DEC-1994 | Wetzel, Nicholas | U.S. Bureau of Mines |
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.