La Primera

Past Producer in San Luis Obispo county in California, United States with commodity Chromium

Geologic information

Identification information

Deposit ID	10286703
MRDS ID	M100576
MAS/MILS ID	0060790030
Record type	Site
Current site name	La Primera
Alternate or previous names	La Primero, Hardface, El Primero
Related records	10103912

Geographic coordinates

Point of reference	Trench
Geographic coordinates:	-120.68767, 35.35967 (WGS84)
Elevation	541
Location accuracy	250(meters)
(click for info)

Geographic areas

Country	State	County
United States	California	San Luis Obispo

Public Land Survey System information

Meridian	Township	Range	Section	Fraction	State
Mount Diablo	029 S	012 E	33	NESE	California

Commodities

Commodity	Importance
Chromium	Primary

Materials information

Materials	Type of material
Chromite	Unknown
Olivine	Unknown
Pyroxene	Unknown
Serpentine	Unknown
Uvarovite	Unknown

Nearby scientific data

Trench (1)	-120.68767, 35.35967	ListMap

Ore body information

Strike

N37E

Dip

10N

Thickness

Depth to top

Width

30M

Length

50M

Area

3HA

Field	Value
Type of Orebody #1	DISSEMINATED
Shape of Orebody #1	TABULAR
Primary mode of Origin	MAGMATIC DIFFER
Primary Ore Control	LITHOLOGY
Degree of Wallrock Alter.	INTENSE
Type of Wallrock Alter. #1	CARBONITIZATION
Strike And Dip	N37E
Minimum Depth to Top	0
Avg. Thick. Unconsol. Mat.	0
Min. Thick. Unconsol. Mat.	0
Total Surface Area (HA)	3
Date of Last Modification	830316

Economic information

Economic information about the deposit and operations

Operation type	Surface-Underground
Development status	Past Producer
Commodity type	Metallic
Deposit size	Small
Significant	No
Discovery year	1890
Year of first production	1890

Mining district

District name	Cuesta Pass

Mineral rights holdings

Type of mineral rights	Minerals Only

Land status

Ownership category	Federal

Ownership information

Type Operator

Owner Pierce Brothers

Home office California

Year 1958
Type Owner

Owner Swartz, Arthur

Interest 100

Home office California

Year 1976

Type	Operator
Owner	Pierce Brothers
Home office	California
Year	1958

Type	Owner
Owner	Swartz, Arthur
Interest	100
Home office	California
Year	1976

Production statistics

Year 1880

Description Lump Ore Mined 250 Mt
Year 1918

Description Lump Ore Mined 25 Mt
Year 1952

Description Ore Mined From 1952-1958 37400 Mt
Year 1952

Description Concentrates Produced From 1952-1958 11400 Mt @ 45.8 Pct-2.3:1 Cr:Fe
Year 1952

Description Lump Ore Mined From 1952-1958 280 Mt @ 44.6 Pct-2.6:1 Cr:Fe

Year	1880
Description	Lump Ore Mined 250 Mt

Year	1918
Description	Lump Ore Mined 25 Mt

Year	1952
Description	Ore Mined From 1952-1958 37400 Mt

Year	1952
Description	Concentrates Produced From 1952-1958 11400 Mt @ 45.8 Pct-2.3:1 Cr:Fe

Year	1952
Description	Lump Ore Mined From 1952-1958 280 Mt @ 44.6 Pct-2.6:1 Cr:Fe

Comments on the reserve resource information

MAT 1 COL 1 REPRESENTS AVERAGE ORE GRADE MAT 1 COL 2 REPRESENTS HIGH GRADE ORE MAT 1 COL 3 REPRESENTS LOW GRADE ORE

Reference information

Links to other databases

Agency	Database name	Acronym	Record ID	Notes
U.S. Bureau of Mines	Minerals Availability System	MAS	0060790030
USGS	Mineral Resources Data System	MRDS	M100576	MAS references MRDS

Bibliographic references

Deposit

CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD, CENTRAL
Deposit

COAST REGION. SURFACE WATER DEGRADATION BY INACTIVE
Deposit

METAL MINES IN NORTHWEST SAN LUIS OBISPO COUNTY, CA,
Deposit

DECEMBER 1993 (P. 6-8).
Deposit

CALIF. STATE MINING BUR. BULLETIN 76, 1918, P. 171.
Deposit

CALIF. DIV. MINES BULLETIN 134, 1953, PART II, CHAPT. 2,
Deposit

P. 61-63.

General comments

Subject category	Comment text
Deposit	325 TONS WAS SHIPPED PRIOR TO 1918.1952-1958 37,390 LT MILLI MINED,11397 LT.CONCENTRATES PRODUCED. 282 LT.LUMP ORE MINED. ORG RAN 44.6% CR2O3,11.5% FE,CR/FE=2.6.CONCENTRATE RAN 45.8% 13.2 PERCENT CR2O3,CR/FE=2.3. RE-SERVE ESTIMATE-50%=5 FOOT P ION OF EXPOSED ORE,25%=10 FOOT,10%=25 FOOT INADEQUATE RESOURCES FOR COST ANALYSIS. ANALYSIS BY CDMG IN 1976 GAVE FOLLOWING PERCENTAGES-MASSIVE 2 01.57,CR2O3 54.08,FEO 10.37,TOTAL FE 14.15,AL203 14.17,MGO CR/FE 3.36.DISSEMINATE ORE=SI02 14.23,CR2O3 33.62,FEO 09.59 FE 16.72,AL203 13.27,MGO 18.82,CR/FE 1.77.

Subject category

Comment text

Deposit

325 TONS WAS SHIPPED PRIOR TO 1918.1952-1958 37,390 LT MILLI MINED,11397 LT.CONCENTRATES PRODUCED. 282 LT.LUMP ORE MINED. ORG RAN 44.6% CR2O3,11.5% FE,CR/FE=2.6.CONCENTRATE RAN 45.8% 13.2 PERCENT CR2O3,CR/FE=2.3. RE-SERVE ESTIMATE-50%=5 FOOT P ION OF EXPOSED ORE,25%=10 FOOT,10%=25 FOOT INADEQUATE RESOURCES FOR COST ANALYSIS. ANALYSIS BY CDMG IN 1976 GAVE FOLLOWING PERCENTAGES-MASSIVE 2 01.57,CR2O3 54.08,FEO 10.37,TOTAL FE 14.15,AL203 14.17,MGO CR/FE 3.36.DISSEMINATE ORE=SI02 14.23,CR2O3 33.62,FEO 09.59 FE 16.72,AL203 13.27,MGO 18.82,CR/FE 1.77.

Reporter information

Type	Date	Name	Affiliation	Comment
Reporter	05-DEC-94	Wetzel, Nicholas	U.S. Bureau of Mines