The Soledad Canyon Ilmenite Mine (P.W. Gillibrand Co.), San Gabriel Mountains, Southern California

Abstract

Abstract The P.W. Gillibrand Company holds 705 placer and lode claims in the Precambrian San Gabriel Anorthosite Complex of the western San Gabriel Mountains. These claims contain large tonnages of ilmenite, magnetite and apatite with anomalous quantities of zirconium (zircon), niobium, vanadium and rare earth elements. Stockpiling of heavy mineral concentrates associated with aggregate mining from alluvial pits has occurred since 1984. The limited reserves of material from these alluvial deposits and their relatively low heavy mineral grades caused Gillibrand Company to initiate an extensive drilling and exploration program to develop the hardrock resources of ilmenite, apatite and magnetite. Surface sampling identified three potential target areas. In 1986 a percussion drilling program was undertaken as a preliminary step in determining the resource potential of the three target areas. By 1987 and 1988, the company changed to a BX size diamond drilling program. The drilling exploration program delineated approximately twenty million tons of combined heavy minerals (ilmenite + apatite + magnetite) in the target areas. Production scale processing of the heavy minerals has occurred since 1984 with more than 20,000 tons of coarse ilmenite sold in 1990 to the export market for titanium pigment production.