Newsboy Mine, Fairbanks Mining District, Fairbanks North Star Borough, Alaska, USAi

Regional Level Types
Newsboy Mine	Mine
Fairbanks Mining District	Mining District
Fairbanks North Star Borough	Borough
Alaska	State
USA	Country

Location: Cobb (1972, MF-413), loc. 37; SE1/4 sec. 26, T. 3 N., R. 1 E., of the Fairbanks Meridian. The Newsboy mine is just south of the saddle between Cleary Creek and Last Chance Creek; it is at an elevation of 1,750 feet, approximately two miles NNE of Pedro Dome.
Geology: The Newsboy mine as one of the major producers of the Cleary Hill area. It began production in 1911 and continued intermittently until World War II. The Newsboy mine is hosted in dark green, massive to tightly foliated chlorite-actinolite schist of basaltic origin. The country rocks trend N 60-80 E and dip 0 to 30 NW (Robinson and others, 1990). Mine dumps also indicate a significant proportion of quartz-biotite-mica schist and quartz-sericite schist with abundant white to granular quartz stockwork and pervasive flood silica (Freeman, 1992). Movement on the main Newsboy structure appears to be of multiple-age, strike-slip character. However, dip-slip displacement is probably present, but difficult to discern due to the intensity and complexity of the movements (Freeman, 1992). The Newsboy shear zone is situated on the northwest limb of the Cleary antiform and is cut by a series of poorly understood, east-west trending faults which dip predominantly to the north at angles ranging from 57 to 80 degrees. These structures truncate the mineralization and despite several hundred feet of drilling and exploratory drifting, the continuation of the shear zone could not be located (Freeman, 1992). Mineralization at the Newsboy mine consists primarily of native gold plus arsenopyrite, some of it auriferous, with lesser amounts of stibnite, chalcopyrite, sphalerite and ubiquitous pyrite (Fairbanks Exploration Inc., unpublished report, 1986). Ore in the Newsboy mine is similar to that at the nearby Tolovana mine, about one mile east and 650 feet lower than the Newsboy shaft (Brooks, 1913). White quartz, shear zones and stockworks range from 2 to 14 feet wide and average about 4 to 5 feet wide in the upper 200 feet of workings (Hill, 1933; Stewart, 1931). Samples collected in 1986 from the Newsboy mine dumps contain high arsenic and gold contents coupled with erratic but generally low antimony and silver contents (Fairbanks Exploration Inc., unpublished report, 1986). Gold values range from 260 ppb to 4.180 troy ounces per ton. Samples taken from mill sulfide concentrates and stamp tailings near the old Newsboy mill contain much gold with abundant arsenopyrite and pyrite. Sulfide-rich mill concentrates varied from 1.433 to 3.377 ounces of gold per ton. Stamp sand tailings returned grades ranging from 0.087 to 0.163 ounces of gold per ton (Fairbanks Exploration Inc., unpublished report, 1986). A significant amount of gold (810 to 5700 ppb) was detected in quartz-sericite schist derived from rhyolite tuff and exhalite (Fairbanks Exploration Inc., unpublished report, 1986).
Workings: The Newsboy mine was first staked June 25, 1909 (Times Publishing Company, 1912). The Newsboy shear zone was traced for several hundred feet on the surface and additional claims were staked. In October, 1911, a 5-stamp Joshua Hendy Mill was erected (Brooks, 1912; Smith, 1913, B 525). The mill operated for only a few months due to lack of water. Brooks (1912) indicated that by mid-1911 the Newsboy Mine shaft had reached the 200-foot level and working drifts had been driven on the 60-foot and 115-foot levels. By the end of 1911 the bottom of the shaft was at the 315-foot level and drifting was being conducted on a 4-foot-wide shear zone on the 215-foot and 315-foot levels. By May 12, 1912, the mill had been moved to placer claim #11 above Discovery on Cleary Creek, about 4,000 feet northeast of and 600 feet lower than the Newsboy mine. Water for the mill was taken from a 100-foot-deep 6-inch well, located near the mill (Smith, 1913; B 525). By 1913, the Newsboy mine was being developed on the 60-, 115-, 168-, 215- and 315-foot levels. The 115-foot level extended 140 feet southwest and 100 feet northeast of the shaft and much of the ore between this level and the 168-foot level had been mined (Chapin, 1914). A few feet east of the shaft on the 115-foot level the shear zone was mined over a 14 foot width. The 315-foot level was accessed by 250 feet of drifts, but this level of the mine was flooded in 1913 (Chapin, 1914). Surface trenching was conducted along the shear zone in 1923 but the mine was idle (Stewart, 1923). During 1931, renovation was completed on the mine and the old mill on upper Cleary Creek (Pilgrim, 1932; Smith, 1933; B 836), and the shaft was opened to the 160-foot level (Hill, 1933). In October, the nearly retrofitted mill burned to the ground. Development work continued in the mine and de-watering was begun in the lower mine levels (Pilgrim, 1932; Stewart, 1933; Hill, 1933). In 1932, a diesel-powered 180-cubic-foot-capacity Sullivan compressor was installed at the mine. One-hundred and fifty tons of ore from above the 215-foot level was shipped seven miles to the Tom Gilmore Mill on Fairbanks Creek. The 215-foot level was reopened in 1932 and minor exploratory work was conducted in 1933 (Smith, 1934; B 864). The Newsboy mill was rebuilt in 1933. New grinding and flotation equipment was added to the mill in 1935 and mining resumed underground (Smith, 1938). In 1938, the mine was de-watered at the 215-foot level (Reed, 1939). A 1200-foot-long surface trench was emplaced and drifting on the 165-foot level took place in 1938; no ore was produced in 1938 (Stewart, 1939). In December, 1940, the prospect was idle (Stewart, 1941).
Alteration: Quartz, sericite and ankerite.
Production: In May of 1911, the Newsboy mine produced a 66 ton ore shipment which yielded $5008.20 in gold, or about 244 ounces of gold. An additional 7.5 tons of ore was shipped in 1911 to the Garden Island Mill in Fairbanks and was reported to contain $104 gold per ton (5 ounces of gold per ton) in free milling gold (Brooks, 1913; Smith, 1913, B 525). Drifting and mining continued at the Newsboy mine in 1913 although no production figures for the year are available (Chapin, 1914). Despite production of nearly $150,000 worth of gold (7250 troy ounces), the mine was shut down in 1915. In 1932, 150 tons of ore from above the 215-foot level was shipped 7 miles to the Tom Gilmore Mill on Fairbanks Creek. The total estimated production from 175 feet to the surface is 35,937 tons of ore and 8,125 tons of waste from which 35,937 troy ounces of gold were recovered (Freeman, 1992).
Reserves: The following discussion of reserves is taken from Freeman (1992) and is based on analysis of old mine maps. Ore reserves blocked out between the 350-foot and 175-foot levels are estimated at 21,875 tons of ore, 10,937 tons of waste and 21,875 ounces of gold in place. The estimated potential ore reserves on the Newsboy shear zone system on the Newsboy prospect are considerably larger. Based on the past production figures, an estimated 75% of the reserves will consist of 4 feet of shear zone in a 6 foot heading; the remaining 25% of the reserves are figured on a 14 feet wide shear zone on 14 feet of heading. Reserves are based on free gold at a grade of 0.5 ounces of gold per ton. Sulfide-encapsulated fine gold is expected to contribute a significant amount to the total gold, however, since reliable figures on the average amount of sulfide-encapsulated gold are not available, no value is given to this form of gold in the geologic reserves. The adjusted total geologic reserves takes into account the 44,062 tons of ore and waste estimated to have been mined from the Newsboy shaft. Based on the above assumptions, the total geologic reserve of the Newsboy shear zone system to the 1200' elevation is 813,938 tons at a grade of 0.5 ounces of gold per ton. It should be noted that the reserves are hypothetical reserves (USBM nomenclature) and as such no dilution or recovery factors have been included in the calculations.

Commodities (Major) - Au; (Minor) - Cu, Sb, Zn
Development Status: Yes; small
Deposit Model: Gold-quartz vein.

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