Magnolia mine, Delamar Mining District, Lincoln County, Nevada, USAi

Regional Level Types
Magnolia mine	Mine
Delamar Mining District	Mining District
Lincoln County	County
Nevada	State
USA	Country

Structure: Abundant Normal Faults Fault In The Quartzite

Deposit: Adit follows n10w, 60s W quartz vein and quartz-cemented quartzite breccia exposed at portal. Vein width is 1-1.5 ft. The quartzite wallrock is fractured and brecciated but has sharp contacts with the vein. Near the vein, the quartzite is cut by quartz veinlets and also contains numerous iron-stained vugs filled with prismatic quartz. The central portion of the main vein is composed of quartz-cemented quartzite breccia containing angular fragments of pink quartzite cemented by a mixture of Mn oxides and chalcedonic quartz. Outward from the breccia are banded comb and chalcedonic quartz veins which are generally vuggy and contain iron oxides and dark streaks which are possibly fine Mn oxides or dispersed sulfides. Quartz stringers fill fractures in the footwall quartzite. These stringers parallel the orientation of the main vein, which is emplaced along a fault, As evidenced by brecciation of host rock and central vein, and by the presence of slicks on the footwall quartzite. Quartz vein material found on the dump is banded, white to vitreous (clear), and cockscomb, sugary or chalcedonic in texture. Comb quartz cements fragments in the breccia. Some oxidized pyrite was observed in iron-stained vugs. Pyritized dark grey finely crystalline siliceous breccia was also noted. Some siliceous or jaspery breccia contained bands of finely crystalline chalcopyrite and pyrite (unoxidized). The siliceous breccias show fine, late-stage quartz veinlets. Malachite, tetrahedrite, psilomelane and pyrolusite were also noted in vein material. Malachite-coated comb quartz vein material on dump contains specks of visible gold. Monzonite porphyry and rhyolitic volcanic rock were found on dump but not located in place.

Development: Small shipments were made in 1920 and 1921. First ore was mined at hiko. In 1931, exploration was undertaken at the magnolia mine and the j.l. Baird and w. L. Aiken lease produced considerable ore in 1932-1933. No activity at time of examination in 1983, but evidence of staking and trenching recently (within past few years) at mouth of canyon.

Geology: Ore is along a dike or volcanic plug of volcanic breccia with numerous rhyolite dikes. Dike is at least 1100 feet long. Average width of workings is 100 feet. The ore breccia consists of quartzite fragments cemented by igneous material, in lenses and pockets

Ore(s): Fracture Zone

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Link to USGS MRDS:	10037390

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References