Lavender Pit 

 

 

Lavender Pit 

 

In 1909, the two intrusive porphyry units began to be explored for ore potential. It was learned that two sections one called the West Orebody and the other the East Orebody lent themselves to mining. The West orebody was mined by the Sacramento Open Pit and the East Orebody was to be mined underground largely with the block- cave method and a few top slicing stopes. Unfortunately, the block-cave stopes failed to adequately collapse and the ore remained in situ. Also, the ore itself, also proved somewhat problematic as it was films of chalcocite (Cu2S) coating pyrite (FeS2.)  It was difficult to separate the valueless pyrite from the desirable chalcocite.  In March 1950, planning began on a new open pit mine. To start mining it was essential that the communities of Jiggerville, Upper Lowell and Johnson Addition were moved. Highway 80 would also be moved north. The topography eliminated the use of trains in the pit and 25-ton haul trucks were chosen to haul rock from the pit. P&H 9 yd. electric shovels loaded the trucks. The haul to the waste dumps initially exceeded the economic limits for a 25 ton truck and the waste was dumped into rail cars and transported to No.7 dump by rail. Stripping of the waste rock began in 1951. After the death, of Phelps Dodge vice-president Harrison Lavender in 1952, the new pit was christened the Lavender Pit. In 1954, the Lavender Pit began producing ore. Following advances in technology, the first 35-ton dump trucks were introduced in 1960. Plans were beginning for the first expansion of the pit. This new area was to mine the southeastern side near the abandoned Hoatson Mine. The first of the 65-ton trucks were purchased in 1963. With these new larger trucks the rail line to No.7 dump ceased and the waste was hauled by truck. In the constant search for ore, exploration began in the Holbrook mine region.  An air raise into the Holbrook mine was reconditioned and a diamond drill was placed underground. Also, drift was driven from the Lavender pit toward the 400 level Gardner. Enough ore was discovered and in 1965, the Holbrook Extension was announced. Most of the Holbrook Extension ore mined was oxides (azurite, malachite, cuprite) and was sent directly to the smelter. The Lavender Pit continued to mine until December 14, 1974.  . In November of 1976, 13, 65 ton trucks, 3, 35 ton trucks and 4 electric shovels were we sent to the Western Nuclear Mine in Spokane Washington. During the decades since mining has ceased erosion has exposed a number of stopes in the walls of the Holbrook Extension. During the Late 1980s and early 1990s it was not uncommon from kids and mineral collectors to enter the pit  and collect enter a stope on the 100 level Holbrook mine to collect largely calcite, but a few interesting Malachite psuedomorphs after azurite specimens. Odd nodules of native copper could be found in a clay zone in the pit wall and for a short time massive calcite tinted by copper was collected and sold locally as “Bisbee Ice” in a short-lived rock polishing fad of the early 1990s.

Location of the  Sacramento pit (almost entirely mined out) to the Lavender pit

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© 2013 by Doug Graeme