Elevation: 5,735 feet
Location: Center of sec. 20, T. 145., R. 20 E., at the head of Johnson Creek on the northeast slope of Lookout Mountain. The property adjoins the Mother Lode mine property on the northeast.
Owners: Independent Quicksilver Co.; Lloyd Bartlett, Salem, secretary-treasurer.
History: The prospect may have been worked initially by early owners of the Mother Lode mine. The pres¬ent company, which was organized by George A. Dreis, acquired ownership in 1930 and has done nearly all of the existing work.
Development: Prospecting efforts have been concentrated in two areas about 1,500 feet apart (figure 48 in image gallery). Both areas have been explored by many hundreds of feet of bulldozer trenches and by several drill holes. The eastern area also includes three adits, one of which is caved. The other two contain, collectively, about 600 feet of workings. A small gravity mill was installed on the property in 1959.
Geology: The west workings are in and along the western edge of a grassy meadow at the head of Johnson Creek. The meadow, which is roughly 200 yards across, is underlain largely by stream and marsh deposits consisting of crossbedded sand and clayey silt. Outcrops are scarce and several of the trenches failed to penetrate the alluvium. Rocks exposed within the meadow and along its periphery include andesite flows, tuffs, and breccias of the Clarno Formation. Dips where ascertainable are of low angle. Along the southeast side of the meadow in the vicinity of the east workings these rocks are overlain, apparently unconformably, by porphyritic andesite.
Within the meadow, cinnabar is sparsely but widely scattered through the alluvium. Its source was not determined by the writer; however, the owners report that, as a result of drilling, several small occurrences of cinnabar have been found in the underlying andesites. Weathering and erosion of the upper parts of such bodies could have contributed the cinnabar.
The two accessible adits of the east workings penetrate hard andesite, crosscutting at irregular intervals some narrow faults. The faults contain from a few inches to a foot of crushed andesite and gouge. Some are impregnated with a little calcite and silica. Cinnabar, though present as fracture coatings and small disseminated crystals, is scarce. One of the opencuts immediately below the adits exposes the varicolored clays and gouge characteristic of shear zones in the Johnson Creek area. Because of inadequate exposure, neither the width nor the attitude of the shear zone could be ascertained. A sample taken from the floor of the cut showed a little cinnabar and pyrite when panned.
Text from Quicksilver in Oregon, Bulletin 55, State of Oregon Department of Geology and Mineral Industries. Author: Howard C. Brooks