J.D. Lyons

Prospect in Alaska, United States with commodity Copper

Geologic information

Identification information

Deposit ID 10094006
MRDS ID A011846
Record type Site
Current site name J.D. Lyons

Geographic coordinates

Geographic coordinates: -144.04957, 62.78079 (WGS84)
Relative position The J.D. Lyons prospect (Cobb, 1979 [OF 79-1247,p. 18]) is at an elevation of about 4,400 feet on the ridge about 1/4 mile south of the confluence of the two headwater forks of Grubstake Creek . It is in the center of the N1/2, section 35, T. 12 N., R. 7 E., Copper River Meridian. Another geologically similar prospect is at an elevation of about 3,700 feet to the north, but south of Grubstake Creek. The location of these prospects is accurate; they are shown as locality 5 of Richter (1966, figure 5, p. 31), locality 16 of Richter and Matson (1972), and locality 15 of MacKevett and Holloway (1977).
(click for info)

Geographic areas

Country State
United States Alaska


Commodity Importance
Copper Primary

Materials information

Materials Type of material
Chalcopyrite Ore
Malachite Ore
Pyrite Ore
Quartz Gangue


  • (Local) Chlorite-hornblende hornfels in altered border phases of the Pennsylvanian to Permian, Ahtell pluton.

Mineral occurrence model information

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

Host and associated rocks

  • Host or associated Host
    Rock type Plutonic Rock > Ultramafic Intrusive Rock > Hornblendite
    Stratigraphic age (youngest) Late Permian

Nearby scientific data

(1) -144.04957, 62.78079

Comments on the geologic information

  • Geologic Description = The Lyons prospect is in hornfelsed, chlorite-hornblende volcanic rocks in the border phase of the Pennsylvanian to Permian, Ahtell pluton (Richter, 1964 and 1966; Richter and Matson, 1968). The hornfels is cut by irregular, discontinuous quartz veins as much as 6 inches thick. The veins and host rock is weakly copper stained (malachite?), and the quartz veins contain small amounts of pyrite and chalcopyrite (Richter 1966, p. 31).
  • Age = The mineralization is probably related either to the Pennsylvanian to Permian, Ahtell intrusive or to mid-Jurassic dioritic rocks exposed east of the occurrence.

Economic information

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Chistochina

Comments on the workings information

  • Workings / Exploration = The prospect on the ridge at an elevation of about 4,400 feet was developed prior to 1963 by prospect pits and by a 10-foot-long adit (Richter, 1964).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A011846
USGS Alaska Resource Data File ARDF GU018

Bibliographic references

  • Deposit

    Richter, D.H., 1964, Geology and mineral deposits of the Ahtell Creek area, Slana District, south-central Alaska: Alaska Division of Geological and Geophysical Surveys Geologic Report 6, 17 p., 1 sheet, scale 1:31,680.

  • Deposit

    Richter, D.H., 1966, Geology of the Slana district on south-central Alaska: Alaska Division of Geological and Geophysical Surveys Geological Report 2l, 36b p., 3 sheets, scale 1:63,360.

  • Deposit

    Richter, D.H., and Matson, N.A., 1968, Distribution of gold and some base metals in the Slana area, eastern Alaska Range, Alaska: U.S. Geological Survey Circular 593, 20 p.

  • Deposit

    Cobb, E.H., 1979, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Gulkana quadrangle, Alaska: U.S. Geological Survey Open-File Report 79-1247, 36 p.

  • Deposit

    Richter, D.H., and Matson, N.A., Jr., 1972, Metallic mineral resources map of the Gulkana quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-419, 1 sheet, scale 1:250,000.

  • Deposit

    MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous and selected non-metalliferous mineral deposits in the eastern part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-A, 99 p., 1 sheet, scale 1:1,000,000.

Comments on the references

  • Primary Reference = Richter, 1966

General comments

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

Reporter information

Type Date Name Affiliation Comment
Reporter 20-DEC-00 W.T. Ellis Alaska Earth Sciences
Reporter 20-DEC-00 Hawley, C.C. Hawley Resource Group
Reporter 20-DEC-00 W.J. Nokleberg U.S. Geological Survey