Broken Neck Creek

Mine, Probably inactive

Commodities and mineralogy

Main commodities Au
Ore minerals gold

Geographic location

Quadrangle map, 1:250,000-scale EA
Quadrangle map, 1:63,360-scale D-2
Latitude 64.9313
Longitude -141.7242
Nearby scientific data Find additional scientific data near this location
Location and accuracy Broken Neck Creek is a small north tributary of the Seventymile River. Prindle (1905) reported that Broken Neck Creek was worked for about one-half mile upstream from the mouth. The coordinates are the approximate midpoint of this part of the creek, in section 7, T. 1 N., R. 30 E., of the Fairbanks Meridian. The location is accurate. Broken Neck Creek is locality 28 of Cobb (1972 [MF-393]), locality 7 of Eberlein and others (1977), and locality 10 of Burleigh and Lear (1994).

Geologic setting

Geologic description

Broken Neck Creek flows through a narrow, steep-walled valley; the canyon walls are only 120 feet apart where the creek emerges onto the Seventymile River flats. Bedrock along the creek consists of Upper Cretaceous to Pliocene conglomerate interbedded with shale containing abundant fossil leaves (Prindle, 1905; Foster, 1976). Placer gold has been produced on the Seventymile River (see EA025) downstream from the mouth of Broken Neck Creek.
In 1903, the placer workings at Broken Neck Creek were 100 feet wide, and extended about one-half mile upstream from the mouth (Prindle, 1905). The pay streak at this time was about 6 feet wide, and total production was about $10,000 (gold at $20.67 per ounce). Mining on Broken Neck Creek is sporadically reported from 1910 to 1940. Gravel worked in Broken Neck Creek was later reported to be 3 to 5 feet thick; the pay streak was 20 to 50 feet wide at the mouth of the canyon and much narrower upstream (Mertie, 1938). Work in the 1930s was confined to benches on the west side of the creek. Most of the gold on the benches was located close to and on bedrock; no coarse gold was recovered. An average of four assays of gold from the benches, collected in four separate years, was 829 parts of gold and 165 parts of silver per thousand (Mertie, 1938). Clark and Foster (1971) found anomalous lead and zinc were found in stream sediments from Broken Neck Creek.
Geologic map unit (-141.726529993635, 64.9309954777307)
Mineral deposit model Placer Au (Cox and Singer, 1986; model 39a).
Mineral deposit model number 39a
Age of mineralization Quaternary.

Production and reserves

Workings or exploration In 1903, the placer workings at Broken Neck Creek were 100 feet wide and extended about one-half mile upstream from the mouth (Prindle, 1905). The paystreak at this time was about 6 feet wide. Mining on Broken Neck Creek is sporadically reported from 1910 to 1940. Gravel worked in Broken Neck Creek was later reported to be 3 to 5 feet thick; the pay streak was 20 to 50 feet wide at the mouth of the canyon and much narrower upstream (Mertie, 1938). Work in the 1930s was confined to benches on the west side of the creek.
Indication of production Yes; small
Production notes Total gold production from Broken Neck Creek as of 1903 was about $10,000 (gold at $20.67 per ounce) (Prindle, 1905). An average of four assays of gold from the benches, collected in four separate years, was 829 parts of gold and 165 parts of silver per thousand (Mertie, 1938).

References

MRDS Number A015131

References

Reporters R.L. Flynn; M.B. Werdon
Last report date 5/1/2002