Damon

Prospect in Alaska, United States with commodity Copper
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 10308615
Record type Site
Current site name Damon

Geographic coordinates

Geographic coordinates: -131.74677, 55.19374 (WGS84)
Relative position The Damon prospect is at an elevation of about 700 feet in, or adjacent to, the valley of an unnamed creek that follows the northwest flank of Punch Hill. The site is on the boundary of sections 17 and 18, T. 77 S., R. 91 E., of the Copper River Meridian. It corresponds to loc. 111 in Elliott and others (1978). The location is accurate within 0.1 mile.

Site location context

Political divisions (FIPS codes)

Ketchikan Gateway(Borough)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

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

Ketchikan SW(quadrangle 1:100,000 scale)

Ketchikan(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Ketchikan(hydrologic unit)

Southern Southeast Alaska(hydrologic accounting unit)

Southeast Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Tongass 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
Copper Primary

Materials information

Materials Type of material
Chalcopyrite Ore
Pyrite Ore
Quartz Gangue

Alteration

  • Probably local silicification, carbonatization, pyritization, and introduction of hydrothermal hematite.

Mineral occurrence model information

Model code 85
USGS model code 22c
Deposit model name Polymetallic veins
Mark3 model number 46

Nearby scientific data

(1) -131.74677, 55.19374

Economic information

Comments on the geologic information

  • Geologic Description = Southern Gravina Island is underlain by an assemblage of undivided Silurian or Ordovician metamorphosed bedded and intrusive rocks; a stock and associated dikes of Silurian trondhjemite that cuts the metamorphic assemblage; and a sequence of Upper Triassic carbonate, clastic, rhyolitic, and basaltic strata that unconformably overlies the older rocks (Berg, 1973, 1982; Berg and others, 1988). The rocks are complexly folded and are cut by high-angle faults and by low-angle thrust faults. In many places, the Triassic rhyolite and the rocks beneath it are permeated by microscopic particles of hydrothermal hematite, giving them a pink, purple, or red hue (Berg, 1973, p. 14). Wright and Wright (1908, p. 140) describes the Damon deposit only as a quartz vein heavily mineralized with pyrite. The vein is in banded chlorite country rock and strikes N20W. The Wrights' description suggests that the Damon and the Plutyas (KC117) prospects are on different parts of the same, NW-striking, vein. Their map (Wright and Wright, 1908, fig. 10), however, shows that the prospects align E-W, not NW-SE, which suggests instead that the veins are on separate, parallel, NW-striking faults. Maas and others' (1995, p. 227) description of the mineral deposits in the Seal Cove area probably applies in general to the Damon prospect. They report that chalcopyrite occurs as vein fillings, disseminations, and in fault breccias west and northwest of Seal Cove. The mineralized breccias have a siliceous matrix. Small quartz-barite veins with galena and sphalerite have been found west of Seal Cove, and on the northeast slopes of Punch Hill. The rocks at or near the Damon prospect are cut by a high-angle fault that strikes north-northeast (Maas and others, (1995, fig 58). Maas and others (1995, p. 227) report that copper mineralization on southern Gravina Island generally is associated with faulting. The deposits are mainly in meta-andesite (greenschist) and trondhjemite, but also in the overlying Triassic strata. The deposits are chiefly chalcopyrite- and pyrite-bearing quartz fissure veins, but the sulfide minerals also occur as disseminations in the metavolcanic rocks, in silicified zones in the trondhjemite, and as clasts or pods in silicified or carbonatized breccia. The character and setting of the deposits suggest that they mainly are polymetallic veins of Late Triassic or younger age.
  • Age = Late Triassic or younger.

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Mining district

District name Ketchikan

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Maas and others, 1995

General comments

Subject category Comment text
Deposit Model Name = Polymetallic veins (Cox and Singer, 1986; model 22c)

Reporter information

Type Date Name Affiliation Comment
Reporter 05-JUL-1999 H.C. Berg U.S. Geological Survey

Beyond USGS

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

Authoritative Alaska resources

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