Saddle (Freegold)

Prospect, Active

Commodities and mineralogy

Main commodities Ag; As; Au; Pb; Sb
Ore minerals arsenopyrite; boulangerite; gold; jamesonite; pyrite; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale LG
Quadrangle map, 1:63,360-scale A-1
Latitude 65.0659
Longitude -147.3613
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Saddle prospect as defined by Freegold Ventures Ltd. in 2008 includes a number of prospects and the McCarty Mine (LG150-156) that were previously described individually in ARDF and these records have been retained for their geologic details and history. The center of the prospect is on the ridge at the head of Fairbanks Creek about 0.2 mile west-northwest of the McCarty Mine as shown on the U.S. Geological Survey, Livengood A-1, 1:63,360-scale topographic map.

Geologic setting

Geologic description

The Saddle prospect as defined by Freegold Ventures Ltd. in 2008 (Freeman, 2008) includes several old prospects and the McCarty Mine (LG150-156). These were previously described individually in ARDF and these records are retained for their geologic detail and history. The older ARDF record for the Saddle prospect (LG151) is particularly informative.
Placid Oil explored the property from 1978 to 1994 and drilled at least 23 core holes, but the results were more generally indicative of mineralization than defining ore reserves (see LG152). As of early 2008, Freegold has mainly conducted reconnaissance, surface sampling, and has examined the numerous old records in anticipation of future drilling and trenching.
Freeman (2008) redefines the Saddle prospect is a 'vein swarm' that includes several prospect and small mines (LG150-151 and LG153-156) and the McCarty (American Eagle) Mine (LG152), which produced about 60,000 ounces of gold prior to WWII from ore that contained about 1.6 ounces of gold per ton. The vein swarm at Saddle has the highest density of parallel veins along the Cleary Hill mineral belt; it extends for about 3,500 feet along strike and has a minimum width of 2,500 feet. The Saddle prospect is at the intersection of the swarm of northwest-trending, high-grade gold-quartz veins and a district-scale northeast-trending fault structure. The veins are in altered Paleozoic quartz-sericite schist; they contain variable amounts of arsenopyrite, pyrite, stibnite, native gold, boulangerite, and jamesonite. The sulfides in the veins are oxidized to a depth of at least 310 feet. Drilling has verified that the mineralization persists to a depth of at least 650 feet and remains open in all directions.
Geologic map unit (-147.363747983252, 65.0654779398379)
Mineral deposit model Quartz veins with arsenopyrite, As-Sb sulfosalts, and stibnite.
Age of mineralization Mid-Cretaceous by analogy with other mineralization in the area.

Production and reserves

Workings or exploration
The Saddle prospect as defined by Freegold Ventures Ltd. in 2008 (Freeman, 2008) includes several old prospects and the McCarty Mine (LG150-156). These were previously described individually in ARDF and these records are retained for their geologic detail and history. The older ARDF record for the Saddle prospect (LG151) is particularly informative.
Placid Oil explored the property from 1978 to 1994 and drilled at least 23 core holes, but the results were more generally indicative of mineralization than defining ore reserves (see LG152). As of early 2008, Freegold has mainly conducted reconnaissance, surface sampling, and has examined the numerous old records in anticipation of future drilling and trenching.
Indication of production Yes; small
Reserve estimates None by modern reserve standards.
Production notes The McCarty/American Eagle Mine in the Freegold prospect area produced about 60,000 ounces of gold prior to WWII; several of the other deposits produced small amounts of ore that was processed through the McCarty mill. There has been no production since 1942.

References

References

Freeman, C.J., 2008, Executive summary report for the Golden Summit project, Fairbanks Mining District, Alaska: Unpublished Technical Report for Freegold Ventures Ltd., 112 p. (posted on www.sedar.com, March 31, 2008).
McCoy, Dan, Newberry, R.J., Layer, Paul, and others, 1997, Pluton-related gold deposits of Interior Alaska, in Goldfarb, R.J., and Miller, L.D., (editors): Economic Geology Monograph 9, p. 191-241.
Reporters D.J. Grybeck (Port Ludlow, WA)
Last report date 6/5/2008