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Harvard Mine (Harvard Mine group; McCann claim; Mooney claim; Pacific claim; Vulture claim; Trio claim; Sobrante claim), Jamestown Mine (Jamestown group), Jamestown Mining District, Tuolumne County, California, USAi
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Latitude & Longitude (WGS84):
37° 56' 44'' North , 120° 26' 12'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Jamestown | 3,433 (2011) | 1.5km |
| Tuttletown | 668 (2011) | 5.5km |
| Sonora | 4,818 (2017) | 6.4km |
| East Sonora | 2,266 (2011) | 7.5km |
| Chinese Camp | 126 (2011) | 8.3km |
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
Local clubs are the best way to get access to collecting localities
| Club | Location | Distance |
|---|---|---|
| Calaveras Gem & Mineral Society | Angels Camp, California | 16km |
Other/historical names associated with this locality:
Harvard Pit
An former lode Au-Ag mine located in sec. 16, T1N, R14E, MDM, 1.6 km (5,200 feet) WSW of Jamestown (S and adjacent to the Crystalline Mine), on private land (private lease; fee ownership; minerals only). Discovered in 1848. Property consists of 6 claims. First production was in 1891. Owned by the Pathfinder Gold Corp. (30.00%), Nevada (1989); and by the Sonora Gold Mining Corp. (70.00%), Canada (1989) (owner-operator). MRDS database stated accuracy for this location is 100 meters. The claims extend for a total distance of nearly 1 mile. Development began in 1850 and was worked intermittently until the 1940's. Several ore shoots up to 200 feet in length have been developed over the years.
Mineralization is a vein deposit hosted in Late Jurassic Cosumnes Formation slate, Logtown Ridge Formation sericite and chlorite schists and an unnamed serpentine. The ore body is a tabular fissure vein body that strikes NW and dips E at a thickness of 60 meters, width of 560 meters, and a length of 490 meters. The primary mode of origin was hydrothermal and the secondary was oxidation. Primary ore control was fracturing and the secondary was a contact zone. Wall rock alteration is intense (dolomitization & silicification). The footwall is serpentine with schist and slate on the hanging wall. Initially, high-grade ore was extracted from narrow quartz veins in serpentine. Later, ore from quartz stringers in mineralized schist was extracted (low-grade). Local rocks include Jurassic marine rocks, unit 1 (Western Sierra Nevada and Western Klamath Mountains).
Workings include underground openings comprised of 2 shafts 1,000 feet apart. The N shaft is 700 feet deep with a winze to 1,850 foot level. The S shaft has levels at 150 foot intervals. The latest development consisted of drilling and drifting.
Production data are found in: Logan (1928).
Production statistics: Year: 1891: 4,995,760 ounces (155,385,526 grams) of Au.
Reserves and resources: Type: In-situ: Inferred: 34,164,000 metric tons ore; total resources: 34,164,000 metric tons ore. Au 3.060000 g/mt; Ag 3.670000 g/mt.
Mineralization is a vein deposit hosted in Late Jurassic Cosumnes Formation slate, Logtown Ridge Formation sericite and chlorite schists and an unnamed serpentine. The ore body is a tabular fissure vein body that strikes NW and dips E at a thickness of 60 meters, width of 560 meters, and a length of 490 meters. The primary mode of origin was hydrothermal and the secondary was oxidation. Primary ore control was fracturing and the secondary was a contact zone. Wall rock alteration is intense (dolomitization & silicification). The footwall is serpentine with schist and slate on the hanging wall. Initially, high-grade ore was extracted from narrow quartz veins in serpentine. Later, ore from quartz stringers in mineralized schist was extracted (low-grade). Local rocks include Jurassic marine rocks, unit 1 (Western Sierra Nevada and Western Klamath Mountains).
Workings include underground openings comprised of 2 shafts 1,000 feet apart. The N shaft is 700 feet deep with a winze to 1,850 foot level. The S shaft has levels at 150 foot intervals. The latest development consisted of drilling and drifting.
Production data are found in: Logan (1928).
Production statistics: Year: 1891: 4,995,760 ounces (155,385,526 grams) of Au.
Reserves and resources: Type: In-situ: Inferred: 34,164,000 metric tons ore; total resources: 34,164,000 metric tons ore. Au 3.060000 g/mt; Ag 3.670000 g/mt.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsCommodity List
This is a list of exploitable or exploited mineral commodities recorded from this region.Mineral List
Mineral list contains entries from the region specified including sub-localities7 valid minerals.
Detailed Mineral List:
| ⓘ Acanthite Formula: Ag2S |
| ⓘ Chenguodaite Formula: Ag9Fe3+Te2S4 |
| ⓘ 'Chlorite Group' Description: Occurs in schist. |
| ⓘ Galena Formula: PbS References: |
| ⓘ Muscovite Formula: KAl2(AlSi3O10)(OH)2 References: |
| ⓘ Muscovite var. Mariposite Formula: K(Al,Cr)2(Al,Si)4O10(OH)2 References: |
| ⓘ Muscovite var. Phengite Formula: KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2 References: |
| ⓘ Muscovite var. Sericite Formula: KAl2(AlSi3O10)(OH)2 Description: Occurs in schist. |
| ⓘ Native Gold Formula: Au References: |
| ⓘ Petzite Formula: Ag3AuTe2 References: |
| ⓘ Quartz Formula: SiO2 References: |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| ⓘ | Native Gold | 1.AA.05 | Au |
| Group 2 - Sulphides and Sulfosalts | |||
| ⓘ | Acanthite | 2.BA.35 | Ag2S |
| ⓘ | Chenguodaite | 2.BA.60 | Ag9Fe3+Te2S4 |
| ⓘ | Petzite | 2.BA.75 | Ag3AuTe2 |
| ⓘ | Galena | 2.CD.10 | PbS |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Quartz | 4.DA.05 | SiO2 |
| Group 9 - Silicates | |||
| ⓘ | Muscovite | 9.EC.15 | KAl2(AlSi3O10)(OH)2 |
| ⓘ | var. Phengite | 9.EC.15 | KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2 |
| ⓘ | var. Sericite | 9.EC.15 | KAl2(AlSi3O10)(OH)2 |
| ⓘ | var. Mariposite | 9.EC.15 | K(Al,Cr)2(Al,Si)4O10(OH)2 |
| Unclassified | |||
| ⓘ | 'Chlorite Group' | - | |
List of minerals for each chemical element
| H | Hydrogen | |
|---|---|---|
| H | ⓘ Muscovite | KAl2(AlSi3O10)(OH)2 |
| H | ⓘ Muscovite var. Phengite | KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2 |
| H | ⓘ Muscovite var. Sericite | KAl2(AlSi3O10)(OH)2 |
| H | ⓘ Muscovite var. Mariposite | K(Al,Cr)2(Al,Si)4O10(OH)2 |
| O | Oxygen | |
| O | ⓘ Muscovite | KAl2(AlSi3O10)(OH)2 |
| O | ⓘ Muscovite var. Phengite | KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2 |
| O | ⓘ Quartz | SiO2 |
| O | ⓘ Muscovite var. Sericite | KAl2(AlSi3O10)(OH)2 |
| O | ⓘ Muscovite var. Mariposite | K(Al,Cr)2(Al,Si)4O10(OH)2 |
| Mg | Magnesium | |
| Mg | ⓘ Muscovite var. Phengite | KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2 |
| Al | Aluminium | |
| Al | ⓘ Muscovite | KAl2(AlSi3O10)(OH)2 |
| Al | ⓘ Muscovite var. Phengite | KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2 |
| Al | ⓘ Muscovite var. Sericite | KAl2(AlSi3O10)(OH)2 |
| Al | ⓘ Muscovite var. Mariposite | K(Al,Cr)2(Al,Si)4O10(OH)2 |
| Si | Silicon | |
| Si | ⓘ Muscovite | KAl2(AlSi3O10)(OH)2 |
| Si | ⓘ Muscovite var. Phengite | KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2 |
| Si | ⓘ Quartz | SiO2 |
| Si | ⓘ Muscovite var. Sericite | KAl2(AlSi3O10)(OH)2 |
| Si | ⓘ Muscovite var. Mariposite | K(Al,Cr)2(Al,Si)4O10(OH)2 |
| S | Sulfur | |
| S | ⓘ Acanthite | Ag2S |
| S | ⓘ Galena | PbS |
| S | ⓘ Chenguodaite | Ag9Fe3+Te2S4 |
| K | Potassium | |
| K | ⓘ Muscovite | KAl2(AlSi3O10)(OH)2 |
| K | ⓘ Muscovite var. Phengite | KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2 |
| K | ⓘ Muscovite var. Sericite | KAl2(AlSi3O10)(OH)2 |
| K | ⓘ Muscovite var. Mariposite | K(Al,Cr)2(Al,Si)4O10(OH)2 |
| Cr | Chromium | |
| Cr | ⓘ Muscovite var. Mariposite | K(Al,Cr)2(Al,Si)4O10(OH)2 |
| Fe | Iron | |
| Fe | ⓘ Muscovite var. Phengite | KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2 |
| Fe | ⓘ Chenguodaite | Ag9Fe3+Te2S4 |
| Ag | Silver | |
| Ag | ⓘ Acanthite | Ag2S |
| Ag | ⓘ Petzite | Ag3AuTe2 |
| Ag | ⓘ Chenguodaite | Ag9Fe3+Te2S4 |
| Te | Tellurium | |
| Te | ⓘ Petzite | Ag3AuTe2 |
| Te | ⓘ Chenguodaite | Ag9Fe3+Te2S4 |
| Au | Gold | |
| Au | ⓘ Native Gold | Au |
| Au | ⓘ Petzite | Ag3AuTe2 |
| Pb | Lead | |
| Pb | ⓘ Galena | PbS |
Other Databases
| Link to USGS MRDS: | 10077946 |
|---|
Localities in this Region
- California
- Tuolumne County
- Jamestown Mining District
- Jamestown Mine (Jamestown group)
- Harvard Mine (Harvard Mine group; McCann claim; Mooney claim; Pacific claim; Vulture claim; Trio claim; Sobrante claim)
- Jamestown Mine (Jamestown group)
- Jamestown Mining District
- Tuolumne County
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- Calaveras-Baker DomainDomain
- Sierra Nevada BatholithVolcanic Arc
USA
- California
- Mother Lode BeltBelt
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References
(n.d.) Minerals Availability System (MAS), U.S. Bureau of Mines.file ID #0061090562
Eric, John H. (1955) Geology and mineral deposits of the Angels Camp and Sonora quadrangles, Calaveras and Tuolumne Counties, California. Special Report 41. California Division of Mines
Allgood, J. (1984), Mill Manager, Sonora Gold Corporation, personal communication to the USGS staff.
Harvard Mine, Jamestown Mine, Jamestown Mining District, Tuolumne County, California, USA