Parker Ranch Chromite deposit (McNear property; Meadowbrook Ranch; Auburn Chrome Mine), Hotaling, Placer County, California, USAi

Regional Level Types
Parker Ranch Chromite deposit (McNear property; Meadowbrook Ranch; Auburn Chrome Mine)	Deposit
Hotaling	- not defined -
Placer County	County
California	State
USA	Country

A former Cr-Fe occurrence/mine located in the S½NE¼ sec. 17, T13N, R8E, MDM, 2.5 km (1.6 miles) WSW of Hotaling (site) and 2.5 km (1.6 miles) N of Elders Corner (Ophir District) (approximately 5.8 miles NNW of Auburn; about ½ mile E of highway 49), on private land. Discovered in 1917 and first produced in 1918. Owned by Calvin H. Oest (100%), California (1976). Operated by Chester C. Butcer & John C. Wold (last operators - 1943-1944), California. Production years were 1918 and the period 1943 to 1944. MRDS database stated accuracy for this location is 10 meters. This deposit is located in a shallow gully on the N side of a knoll.

Mineralization is hosted in serpentinite. The ore body strikes N-S and dips 80E at a thickness of 15 meters, a width of 6.1 meters and a length of 46 meters. Ore body No. 1 is tabular, disseminated. Ore body No. 2 is in a shear zone & irregular in form. Ore body No. 3 is lenticular. The primary mode of origin is magmatic differentiation. Primary ore control was lithology and the secondary control was igneous activity. This deposit lies near the N end of a N-S-trending, irregularly-shaped peridotite body that is exposed over an area 2.5 miles by 1 mile and is bordered by pre-Cretaceous metavolcanics. It consists of a zone of streaks and small lenses of disseminated ore occurring in a small mass of serpentine near the contact with a mass of diabase (?). The ore body was said to be 40 feet wide in the glory hole but probably averages 20 feet with a depth of about 40 feet. The ore is fine-grained and tenor ranges widely (8 to 40% Cr2O3). Wallrock alteration is intense (carbonitization). Local rocks include ultramafic rocks, chiefly Mesozoic, unit 2 (Western Sierra Nevada and Klamath Mountains) and/or Mesozoic volcanic rocks, unit 2 (Western Sierra Foothills and Western Klamath Mountains).

Workings include surface and underground openings. The underground openings have a length of 74 meters and an overall depth of 9 meters. An access tunnel (caved at portal) is about 140 feet long with 2 interconnected stopes, or glory holes, crosscuts, drifts. Surface openings are comprised of 2 large pits and several smaller cuts. Two tunnels and a shaft are caved.

Production data are found in: Rynearson, Garn Arthur (1953).

Total production (1918 & 1943-1944) was about 505 long tons of ore.

Reserves and resources data: Type: in-situ (estimate year = 1953): Inferred: 5,000 METRIC TONS; Total resources: 7,000 metric tons of ore. Cr2O3 content = 8 weight percent. Cr:Fe = 1.53.

Analytical data results: 43.93% Cr2O3; 19.7% Fe; Cr:Fe 1.53:1.

Other Databases

Link to USGS MRDS:	10043718

Other Regions, Features and Areas containing this locality

References