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Agostino

Past Producer in Alaska, United States with commodities Gold, Silver, Copper, Molybdenum, Lead, Zinc
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Alteration
  8. Mineral occurrence model information
  9. Nearby scientific data
  10. Economic information about the deposit and operations
  11. Mining district
  12. Links to other databases
  13. Bibliographic references
  14. General comments
  15. Reporter information

Geologic information

Identification information

Deposit ID 10000983
MRDS ID A011655
Record type Site
Current site name Agostino
Alternate or previous names Barnes Property, Monarch Mining Co., Crow Creek Mining Co.

Geographic coordinates

Geographic coordinates: -149.11262, 61.04648 (WGS84)
Relative position Located on east side of Crow Creek about 0.7 miles south of VABM Pass (Crow Pass), mine is marked with the westernmost adit symbol on Jewell Mountain in the Anchorage A-6 1:63,360-scale map. Locality 53 of Cobb (1972) and locality 42 of MacKevett and Holloway (1977). Accurate within 400 ft.

Site location context

Political divisions (FIPS codes)

Anchorage(Municipality)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Anchorage A-6(quadrangle 1:63,360 scale)

Anchorage SW(quadrangle 1:100,000 scale)

Anchorage(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Anchorage(hydrologic unit)

Knik Arm(hydrologic accounting unit)

South Central Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Chugach National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Silver Secondary
Copper Secondary
Molybdenum Secondary
Lead Secondary
Zinc Critical Secondary

Comments on the commodity information

  • Ore Material = argentiferous galena

Materials information

Materials Type of material
Silver Ore
Arsenopyrite Ore
Chalcopyrite Ore
Gold Ore
Molybdenite Ore
Pyrite Ore
Pyrrhotite Ore
Silver Ore
Sphalerite Ore
Galena Ore
Calcite Gangue
Quartz Gangue

Alteration

  • (Local) The intrusive rocks have undergone argillic alteration. Some galena has been altered to cerussite (Johnson, 1912). Limonite and abundant scorodite is also present where arsenopyrite is prominent (Hoekzema and other, 1987).

Mineral occurrence model information

Model code 274
USGS model code 36a.1
Deposit model name Low-sulfide Au-quartz vein, Chugach-type
Mark3 model number 26

Nearby scientific data

(1) -149.11262, 61.04648
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = Park (1933) decribed the geology: Two quartz veins (called the North vein and the South vein by the owners) cut Late Cretaceous age metasedimentary rocks of the Valdez Group which are intruded by many dikes and small, irregular shaped intrusive bodies of holocrystalline argillically altered quartz diorite. Locally, the bedded rocks strike nearly west and dip 40 N. The country rock has been badly shattered near the veins, and part of the deformation is postmineral, resulting in brecciated vein materials, which in some places have been recemented and again fractured. Both the North and the South veins are traceable for several hundred feet along strike. The South quartz vein ranges in width from 6 inches to about 4 feet, with an average of 9 inches in the tunnel. The strike is from east to S 80 E, and the dip is 55 to 70 N. Many fragments of country rock are isolated in the quartz. The North quartz vein strikes N 80 E, and dips about 70 N. Where exposed in the tunnel and in several surface cuts it is from 10 inches to 3 feet wide, with an average of 1 foot. The North vein appears to be somewhat better defined than the South vein and may be traced farther on the surface. There are several crosscutting veins 6 inches wide that strike a few degrees west of north and dip either east or west. The North vein offsets these small veins. The crosscutting veins of this north-south system are very persistent and one mineralized vein 6 to 8 inches wide was followed for more than 500 feet. The mineralization includes at least two generations of quartz, small amounts of calcite, galena, arsenopyrite, sphalerite, chalcopyrite, pyrrhotite, molybdenite, pyrite, gold, and silver. The silver occurs alloyed with gold (75 percent Au, 25 percent Ag). When not with gold, the silver seems to be associated with galena. Considerable magnetite is found in the concentrates obtained by panning.? A random samples of molybdenum-bearing cross-vein contained 0.26 percent Mo (Park, 1933). Samples taken by the Bureau of Mines contained up to 234 ppm Au and 92 ppm Ag (Hoekzema and others, 1987). Jansons and others (1984) report 43 chip and grab samples contained from a trace to 6.82 oz/ton Au, trace to 3.94 oz/ton Ag, up to 400 ppm Mo, and 1.34 percent As. Weighted average grade of all chip samples is 0.31 oz/ton Au and 0.31 oz/ton Ag.
  • Age = Tertiary or younger

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Anchorage

Comments on the production information

  • Production Notes = Total recorded production, including that of the Jewel Mine (ARDF number AN107), was 4,932 oz gold and 996 oz silver (Hoekzema and others, 1987).

Comments on the workings information

  • Workings / Exploration = Berg and Cobb (1967) indicated the Agostino Mine was the site of the most extensive development in the Girdwood area. The site was discovered by Conrad Hores in 1909 and prospected or mined (with interruptions) until as recently as 1941. Johnson (1912) reports that development began in 1910. In 1910-11 there were about 675 feet of underground workings on three levels and some open cuts. Owners reported that the free milling ore from main veins averaged $35 to $40 per ton (gold at $20.67/ton), with much higher assays from single samples. Wall rocks were said to not be gold-bearing. After 1911, Brooks (1922) reported plans for some work in 1920 and Smith (1929) reported plans for adding machinery in 1926. Minor production occurred in 1926 and 1928 using a 1-stamp mill, small crusher, and amalgamation plate. Park (1933) indicated the group of claims was originally known as the Barnes property and has changed owners several times. The Monarch Mining Co obtained control several years prior to 1933. This company was taken over by the Crow Creek Mining Co., Inc. which gave a lease and option to the Bruno Agostino Mining Co. - controlled and operated by four men in partnership. The last group pushed development vigorously during 1931, installing a larger mill that utilized hydropower and three 1,200-foot tram lines (Hoekzema and others, 1987). Development of the property, 1933, included opening two parallel veins, called by the owners the North and South veins. There is one adit 260 feet long on the North vein and one 267 feet long on the South vein. In addition, there are two crosscutting adits, one containing 295 feet of workings and the other 60 feet. A lower adit, planned to crosscut the workings in depth, has been driven 190 feet. A winze on the South vein was open for 40 feet and was reported to be 10 feet deeper but filled with debris. There was also a 10-foot winze on the South vein. The total workings is 1,072 feet and the winze length more than 50 feet (Park, 1933). Production continued from 1933 until 1941. Roehm (1937) reported that development in 1937 consisted of 950 feet of drift, 125 feet of crosscuts, 52 feet of winze, and 4 raises totaling 100 feet. Two levels at elevations of 3,200 ft and 3,300 ft developed the South vein. The North vein was developed on two levels at elevations of 3,285 ft and 3,420 ft. A 60-ft-long adit was developed 500 feet north of the North vein at an elevation of 3,500 ft to examine a north-striking molybdenum-chalcopyrite-bearing vein. Most of the stoping and production appears to have come from the upper level of the south vein.? A random sample of molybdenum-bearing cross-vein contained 0.26 percent Mo (Park, 1933). Samples taken by the Bureau of Mines (Hoekzema and others, 1987) contained up to 234 ppm Au and 92 ppm Ag. Jansons and others (1984) report 43 chip and grab samples contained from a trace to 6.82 oz/ton Au, trace to 3.94 oz/ton Ag, up to 400 ppm Mo, and 1.34 percent As. Weighted average grade of all chip samples is 0.31 oz/ton Au and 0.31 oz/ton Ag. This deposit has high mineral development potential for a small mine, based on history and sampling, if vein extension can be located (Jansons and others, 1984).

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Park, 1933

General comments

Subject category Comment text
Deposit Model Name = Chugach-type low-sulfide Au-quartz veins (Bliss, 1992; model 36a.1)
Deposit Other Comments = There is some confusion in literature distinguishing between this property and the Jewel mine, which apparently was connected to Agostino mill at one time. Both were probably under the same management (Crow Creek Mining Co.) during the 1930's.

Reporter information

Type Date Name Affiliation Comment
Reporter 30-JUL-1998 D.P. Bickerstaff U.S. Geological Survey
Reporter 30-JUL-1998 S.W. Huss U.S. Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Maps centered on this site

Authoritative Alaska resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.