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Saddle

Prospect in Alaska, United States with commodities Gold, Silver, Antimony
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Geologic information

Identification information

Deposit ID 10307740
Record type Site
Current site name Saddle

Geographic coordinates

Geographic coordinates: -147.36495, 65.06468 (WGS84)
Relative position The saddle prospect is located on the divide between Wolf Creek and Fairbanks Creek; NW1/4 sec. 28, T. 3 N., R. 2 E., of the Fairbanks Meridian.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Silver Secondary
Antimony Secondary

Materials information

Materials Type of material
Gold Ore
Silver Ore
Stibnite Ore

Nearby scientific data

(1) -147.36495, 65.06468
ListMap

Comments on the geologic information

  • Geologic Description = Prior to 1969, the divide between Fairbanks and Wolf Creeks was host to several producing mines and numerous prospects. The mineralization sought in all of these mines and prospects was high grade gold mineralization hosted by large northwest and northeast trending shear zones. Low grade mineralization was known to be present at the McCarty (ARDF no. LG152), Pioneer (ARDF no. LG155) and Pennsylvania (ARDF no. LG156) mines, along the margins of higher grade portions of the shear zones. However, these lower grade zones could not be profitably worked using the existing technology (W. McCarty, oral commun., 1988). In 1969, International Minerals and Chemicals (IMC) began an exploration program designed to address the possibility of surface mining the lower grade material in this area. IMC conducted trenching and rotary drilling targeted at low grade, zones adjacent to previously mined high grade shear zones. These activities resulted in discovery of the Saddle prospect (Pilkington, 1970). . IMC's initial exploration efforts on the Saddle prospect consisted of geological mapping and sampling of four, previously excavated trenches and open cuts. IMC also excavated 5 new dozer trenches totalling 4,299 feet. Initial sampling was conducted in three trenches previously excavated by Keystone Mines Inc. One of these trenches was located in the footwall of the Pennsylvania shear zone, approximately 1,300 feet northeast of the Pioneer shaft . This trench exposed a schist-hosted quartz-bearing shear zone oriented N 35 E, 65 NW. One-foot channel samples collected in the hanging wall of this shear included 9 feet that assayed 0.9 ppm gold (0.029 ounces of gold per ton) and 58.3 ppm silver (1.70 ounces of silver per ton). The rocks consisted of iron-, arsenic- and antimony-oxide-stained silver-gray schist. IMC also sampled two dozer trenches previously excavated by Keystone Mines approximately 500 feet west of the Pioneer shaft. These two dozer trenches cut the Pioneer shear zone which trends N 70 W and dips 50 S. The first trench had 17 feet that assayed 0.54 ppm gold (0.016 ounces of gold per ton) and 75.6 ppm silver (2.20 ounces of silver per ton); the rocks in the trench consisted of brecciated and silicified quartz-mica schist containing minor iron- and antimony-oxide staining. The second trench had 25 feet that assayed 5.68 ppm gold (0.166 ounces of gold per ton) and 142.6 ppm silver (4.16 ounces of silver per ton) in silicified and brecciated quartz-mica schist with weak iron-oxide staining. In order to test the down-dip extent of suspected northeast-trending mineralization picked up in trenches on the Saddle prospect, IMC conducted rotary drilling using a 5-inch rotary drilling rig (Pilkington, 1970). Two vertical rotary holes totalling 485 feet were drilled on the Saddle prospect. Based on the results from trenching and drilling, IMC calculated drill inferred reserves of 2,111,000 tons grading 0.037 ounces of gold per ton and 0.46 ounces of silver per ton in the Saddle Zone (Pilkington, 1970). These reserves were considered subeconomic at then-current gold and silver prices and IMC terminated its lease with Keystone Mines Inc. in 1970.

Economic information

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Inactive

Mining district

District name Fairbanks

Comments on the reserve resource information

  • Reserves = Based on the results from trenching and drilling, IMC calculated drill inferred reserves of 2,111,000 tons grading 0.037 ounces of gold per ton and 0.46 ounces of silver per ton in the Saddle Zone (Pilkington, 1970). These reserves were considered subeconomic at then-current gold and silver prices and IMC terminated its lease with Keystone Mines Inc. in 1970.

Comments on the workings information

  • Workings / Exploration = In 1969 International Minerals and Chemicals (IMC) began an exploration program designed to address the possibility of surface mining the lower grade material in this area. IMC conducted trenching and rotary drilling targeted at low-grade zones adjacent to previously mined high-grade shear zones. These activities resulted in discovery of the Saddle prospect (Pilkington, 1970). IMC's initial exploration efforts on the Saddle prospect consisted of geological mapping and sampling of four previously excavated trenches and open cuts. IMC also excavated five new dozer trenches totalling 4,299 feet. Initial sampling was conducted in three trenches previously excavated by Keystone Mines Inc. IMC also sampled two dozer trenches previously excavated by Keystone Mines approximately 500 feet west of the Pioneer shaft. IMC conducted rotary drilling using a 5-inch rotary drilling rig (Pilkington, 1970). Two vertical rotary holes totalling 485 feet were drilled on the Saddle prospect. In 1987, Keystone Mines leased their holdings to Fairbanks Exploration Inc. and in 1988 BP Minerals, acting as operator of a joint venture with Fairbanks Exploration Inc. conducted drilling designed to confirm and expand on the results previously generated by IMC. BP Minerals drilled 3,465 feet of reverse circulation drilling in 7 holes Klessig (1988).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF LG151

Bibliographic references

  • Deposit

    Pilkington, H.D., 1970, Keystone Mines Inc. exploration program summary: International Minerals & Chemicals Corporation, 61 p. , 1 plate.

  • Deposit

    Klessig, P., 1988, 1987-1988 Summary report for the Cleary Summit JV: BP Minerals America, 9 p.

  • Deposit

    Freeman, C.J., 1992, 1991 Golden Summit project final report, volume 2: Historical summary of lode mines and prospects in the Golden Summit project area, Alaska: Avalon Development Corp., 159 p. (Report held by Freegold Recovery Inc. USA, Vancouver, British Columbia.)

Comments on the references

  • Primary Reference = Pilkington, 1970

General comments

Subject category Comment text
Deposit Model Name = Gold-quartz veins.

Reporter information

Type Date Name Affiliation Comment
Reporter 04-MAY-99 C.J. Freeman, J.R. Guidetti Schaefer Avalon Development Corporation