Nelson and Tift

Mine, Inactive

Commodities and mineralogy

Main commodities Ag; Au; Cu; Pb
Ore minerals bornite; chalcopyrite; galena; gold; magnetite; pyrite
Gangue minerals calc-silicate minerals; quartz

Geographic location

Quadrangle map, 1:250,000-scale PR
Quadrangle map, 1:63,360-scale D-6
Latitude 54.8017
Longitude -131.9743
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Nelson and Tift Mine is on the north shore of McLean Arm, 0.8 mile west of Island Point at the entrance to the arm; it is in Sec. 33, T. 81 S., R. 90 E., of the Copper River Meridian. The location is accurate and the mine is shown by symbol on the current US Geological Survey 1:63,360-scale topographic map.

Geologic setting

Geologic description

The Nelson and Tift Mine was unusual in that it was found by two prospectors, mostly mined by them at low cost, and returned a profit with little legal or operational complications (Wilcox, 1937; Roehm, 1939, Roehm, 1942,; Roppel, 2005). The deposit was found in 1935 by two fishermen, Otto Nelson and R.C. Tiff along the exposed shoreline in an area that previously had been prospected for many years. A 2,150-pound test shipment was sent to the Tacoma smelter and assayed 0.785 ounce of gold per ton. Nelson and Tift then proceeded to mine in a pit just above sea level with a small compressor and jackhammer and sent a 50-ton ore shipment to the smelter in 1936. They then leased the property to the Anaconda Copper Company who mined for a year, periodically sending out barges of sulfide rich ore that proved to be worth $50 to $770 a ton. Anaconda drilled four holes on the deposit and concluded that while rich, it was small. At the end of the year, the property reverted to Nelson and Tift who continued to mine. In 1938, they shipped 1,076 tons of ore to the smelter with a return of $34,000 in gold and silver. A small flotation mill was set up to concentrate the sulfides in the ore and a search continued into the 40s for more mineralization with no success. Nelson reported that about 1,300 tons of ore was mined and that the total return was about $111,000 in gold and silver with some copper and lead.
The rocks in the area of the Nelson and Tift mine (MacKevett, 1963, pl. 1) consist of a Cretaceous quartz diorite stock; thin roof pendants of Devonian (?) marble and calc-silicate rock; and numerous Tertiary andesite or dacite dikes that cut both the stock and the roof pendants.
The deposit (MacKevett, 1963, p. 99-100) consisted of a sulfide lens 75 feet long, 30 feet deep, and 9 feet wide, in a steeply dipping, 20- to 40-ft wide roof pendant of marble that has been intruded by quartz diorite. Near the intrusive contacts, parts of the pendant have been converted to calc-hornfels. The ore consisted largely of auriferous pyrite, accompanied by small amounts of chalcopyrite and bornite. A few pyrite-bearing quartz veins up to 6 inches thick that cut the pendant contain gold. Pyrite and a little magnetite are disseminated in parts of the marble.
Geologic map unit (-131.975971088789, 54.801357136708)
Mineral deposit model Au skarn (Cox and Singer, 1986; model 18b).
Mineral deposit model number 18b
Age of mineralization Probably Cretaceous or younger.

Production and reserves

Workings or exploration The Nelson and Tift Mine was unusual in that it was found by two prospectors, mostly mined by them at low cost, and returned a profit with little legal or operational complications (Wilcox, 1937; Roehm, 1939, Roehm, 1942; Roppel, 2005). The deposit was found in 1935 by two fishermen, Otto Nelson and R.C. Tiff along the exposed shoreline in an area that previously had been prospected for many years. A 2,150-pound test shipment was sent to the Tacoma smelter and assayed 0.785 ounce of gold per ton. Nelson and Tift then proceeded to mine in a pit just above sea level with a small compressor and jackhammer and sent a 50-ton ore shipment to the smelter in 1936. They then leased the property to the Anaconda Copper Company who mined for a year, periodically sending out barges of sulfide rich ore that proved to be worth $50 to $770 a ton. Anaconda drilled four holes on the deposit and concluded that while rich, it was small. At the end of the year, the property reverted to Nelson and Tift who continued to mine it. In 1938, they shipped 1,076 tons of ore to the smelter with a return of $34,000 in gold and silver. A small floatation mill was set up to concentrate the sulfides in the ore and a search continued into the 40s for more mineralization with no success.
Indication of production Yes; small
Reserve estimates The ore body was apparently mined out.
Production notes Nelson (Roehm, 1942) reported that about 1,300 tons of ore was mined and the total return was about $111,000 in gold and silver with some copper and lead.

References