Mespelt

Prospect in Alaska, United States with commodities Silver, Lead, Uranium, Gold, Tin, Tungsten, Zinc

Geologic information

Identification information

Deposit ID	10096773
MRDS ID	A011561
Record type	Site
Current site name	Mespelt

Geographic coordinates

Geographic coordinates:	-152.21286, 62.88952 (WGS84)
Relative position	The Mespelt prospect is located at the end of the trail shown in the east half of Section 2, T. 32 N., R. 16 W., of the Seward Meridian. C.C. Hawley and Associates, Inc. (1978, Fig. 4.2-C) locate this prospect approximately 800 feet east-southeast of Little Mountain at about 4300 feet. Also shown by Reed and others (1978) as locality 5.
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Geographic areas

Country	State
United States	Alaska

Commodities

Commodity	Importance
Silver	Primary
Lead	Primary
Uranium	Primary
Gold	Secondary
Tin	Secondary
Tungsten	Secondary
Zinc	Secondary

Comments on the commodity information

Ore Material = Ytterbium

Materials information

Materials	Type of material
Galena	Ore
Pyrite	Ore
Sphalerite	Ore
Metazeunerite	Ore
Zeunerite	Ore
Calcite	Gangue
Limonite	Gangue
Quartz	Gangue
Siderite	Gangue

Alteration

(Local) Greisen assemblages of quartz-tourmaline-muscovite-chlorite are developed locally (C.C. Hawley and Associates, Inc. 1978).

Mineral occurrence model information

Model code	47
USGS model code	15b
Deposit model name	Sn veins

Host and associated rocks

Host or associated Host

Host or associated	Host

Nearby scientific data

(1)	-152.21286, 62.88952	ListMap

Comments on the geologic information

Geologic Description = The Mespelt prospect consists of two bulldozer cuts, several prospect pits, and a 40 foot shaft (now caved) constructed to evaluate a 7-foot-wide, 1000-foot-long quartz-carbonate vein that cuts the Tertiary-age Tonzona granitic pluton (Tmt), part of the McKinley sequence mapped by Reed and Nelson (1980). The vein, comprised of argentiferous galena, low-grade uranium, and tin mineralization, occurs beneath a gossan cap. High grade grab samples collected in 1959 contained 0.18 to 32.91 oz/ton Ag; trace Au, up to 46.4% Pb, 0.037 to 0.14% eU, up to 2.52% Sb, up to 0.06% Sn, and 0.01 to 0.04% W. A chip sample collected in 1956 assayed 56.3% WO3 (Maloney and Thomas,1966, Table 3; Reed and others, 1978). Greisen assemblages of quartz-tourmaline-muscovite are developed adjacent to the vein. Tin in excess of 1,500 ppm in the nonmagnetic heavy-mineral concentrates from stream silt samples collected from the Camp Creek drainage to the west of this prospect is reported by Curtin, Karlson, Tripp, and Day (1978).? the geologic setting of the Mespelt silver-lead-tin-tungsten vein is described, as follows, by C.C. Hawley and Associates, Inc., (1978) and Reed and Nelson (1980). Blocky slate, argillite, thin-bedded siliceous limestone and chert define a belt of lower Paleozoic sedimentary and metavolcanic rocks (possibly Keevy Peak, Totalanika series, or equivalents) bordered by the Tonzona granitic pluton. The granite has three phases: a coarse-grained, locally porphyritic biotite granite; a medium-grained biotite granite; and a late fine-grained, leucocratic, locally aplitic, muscovite - tourmaline granite in which ovoid clusters of small black tourmaline crystals give the rock a 'dalmatian' appearance. Muscovite may exceed biotite and accessory minerals include tourmaline with lesser amounts of topaz, fluorite, garnet, zircon, and apatite. Late-stage greissen veinlets, like those at the Mespelt propect, contain muscovite, topaz, tourmaline, locally abundant beryl, and occasionally, cassiterite. Lead, silver and tin mineralization occurs in Paleozoic metasediments and metavolcanic rocks along the north and northeast contact of the pluton. The Tonzona pluton has metamorphosed the country rocks to skarn assemblages along the contact and has formed skarn hosted polymetallic mineralization such as at the Jiles-Knudson (TL 004), Boulder Creek (TL073) and the nearby Hogback prospect (TL006). ? In much of the literature, the Jiles-Knudson, Mespelt, Hogback and Boulder Creek are included as the Purkeypile group of lode claims.
Age = Tertiary; mineralization in the Boulder Creek, Jiles-Knudson , Hogback and Mespelt areas is interpreted to be linked to the Tonzona granite (Tmt), part of the McKinley Sequence, that has been determined to range from 52.3 to 56.2 m.y. in age (Reed and Lanphere, 1972; Reed and Nelson, 1980).
Age = Chron age is for McKinley Sequence.

Economic information

Economic information about the deposit and operations

Development status	Prospect
Commodity type	Metallic

Mining district

District name	McGrath

Comments on the production information

Production Notes = No published information available.

Comments on the workings information

Workings / Exploration = Workings consist of two bulldozer cuts, prospect pits, and a 40-foot shaft (now caved) (C.C. Hawley and Associates, Inc., 1978).

Reference information

Links to other databases

Agency	Database name	Acronym	Record ID	Notes
USGS	Mineral Resources Data System	MRDS	A011561
USGS	Alaska Resource Data File	ARDF	TL005

Bibliographic references

Deposit

Capps, S.R., 1925, An early Tertiary placer deposit in the Yentna district: U.S. Geological Survey Bulletin 773, p. 53-61.
Deposit

Maloney, R.P., and Thomas, B.I., 1966, Investigation of the Purkeypile prospects, Kuskokwim River basin, Alaska: U.S. Bureau of Mines Open-File Report 5-66, 12 p.
Deposit

Berg, H.C., and Cobb, E.H., 1967, Metalliferous Lode Deposits of Alaska. U.S. Geological Survey Bulletin 1246, 254 p.
Deposit

Reed, B.L., and Lanphere, M.A., 1972, Generalized geologic map of the Alaska-Aleutian range batholith showing potassium-argon ages of the plutonic rocks: U.S. Geological Survey Miscellaneous Field Studies Map MF-372, 2 sheets, scale 1:1,000,000.
Deposit

Conwell, C.N., 1977, Boulder Creek tin lode deposits: Alaska Division of Geological and Geophysical Surveys Geologic Report 55, p. 35 -38.
Deposit

Curtin, G.C., Karlson, R.C., Tripp, R.B., and Day, G.W., 1978, Geochemical and generalized geologic map showing the distribution of tin, tungsten, and beryllium, Talkeetna quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-870-F, 2 sheets, scale 1:250,000.
Deposit

C.C. Hawley and Associates, Inc., 1978, Mineral appraisal of lands adjacent to Mt. McKinley National Park, Alaska: U.S. Bureau of Mines Open-File Report 24-78, 275 p., 7 plates.
Deposit

Reed, B.L., Nelson, S.W., Curtin, G.C., and Singer, D.A., 1978, Mineral resources map of the Talkeetna Quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-870-D, 1 sheet, scale 1:250,000.
Deposit

Cobb, E.H., and Reed, B.L., 1980, Summaries of data and lists of reference to metallic and selected nonmetallic mineral deposits in the Talkeetna quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-884, 106 p.
Deposit

Reed, B.L., and Nelson, S.W., 1980, Geologic map of the Talkeetna quadrangle: U.S. Geological Survey Miscellaneous Investigations Map I-1174, 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.
Deposit

Capps, S.R., 1927, The Toklat-Tonzona River region: U.S. Geological Survey Bulletin 792-C, p. 73-110.
Deposit

Clark, A.L., and Cobb, E.H., 1972, Metallic mineral resources map of the Talkeetna quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-369, 1 sheet, scale 1:250,000.

Comments on the references

Primary Reference = Maloney and Thomas, 1966

General comments

Subject category	Comment text
Deposit	Model Name = Fringe zone of Pb, Zn, and Ag sulfide mineralization to tin veins (generally related to the tin vein model of Cox and Singer, 1986; model 15b).
Deposit	Other Comments = High grade samples were taken by the U.S. Bureau of Mines in 1959 and by the Alaska Division of Geological and Geophysical Surveys (C.C. Hawley and Associates, Inc., 1978). In much of the literature, the Jiles-Knudson, Mespelt, Hogback and Boulder Creek are included as the Purkeypile group of lode claims.? High grade grab samples collected in 1959 contained 0.18 to 32.91 oz/ton Ag; trace Au, up to 46.4% Pb, 0.037 to 0.14% eU, up to 2.52% Sb, up to 0.06% Sn, and 0.01 to 0.04% W. A chip sample collected in 1956 assayed 56.3% WO3 (Maloney and Thomas,1966, Table 3; Reed and others, 1978). Greisen assemblages of quartz-tourmaline-muscovite are developed adjacent to the vein. Tin in excess of 1,500 ppm in the nonmagnetic heavy-mineral concentrates from stream silt samples collected from the Camp Creek drainage to the west of this prospect is reported by Curtin, Karlson, Tripp, and Day (1978).

Subject category

Comment text

Deposit

Model Name = Fringe zone of Pb, Zn, and Ag sulfide mineralization to tin veins (generally related to the tin vein model of Cox and Singer, 1986; model 15b).

Deposit

Other Comments = High grade samples were taken by the U.S. Bureau of Mines in 1959 and by the Alaska Division of Geological and Geophysical Surveys (C.C. Hawley and Associates, Inc., 1978). In much of the literature, the Jiles-Knudson, Mespelt, Hogback and Boulder Creek are included as the Purkeypile group of lode claims.? High grade grab samples collected in 1959 contained 0.18 to 32.91 oz/ton Ag; trace Au, up to 46.4% Pb, 0.037 to 0.14% eU, up to 2.52% Sb, up to 0.06% Sn, and 0.01 to 0.04% W. A chip sample collected in 1956 assayed 56.3% WO3 (Maloney and Thomas,1966, Table 3; Reed and others, 1978). Greisen assemblages of quartz-tourmaline-muscovite are developed adjacent to the vein. Tin in excess of 1,500 ppm in the nonmagnetic heavy-mineral concentrates from stream silt samples collected from the Camp Creek drainage to the west of this prospect is reported by Curtin, Karlson, Tripp, and Day (1978).

Reporter information

Type	Date	Name	Affiliation	Comment
Reporter	10-AUG-98	Madelyn A. Millholland	Millholland & Associates