Scrub Oaks

Location: New Jersey, United States (40.891, -74.601 approx.)

Commodities: iron; rare earth elements

Deposit model: iron oxide-apatite · low Ti-Fe-oxide, Cu-Au-U-REE

Geology

The mine workings consist of a four-compartment shaft and six working levels that average about 5,000 feet in length. The north end of the 6th level had not been developed at the time of Sims (1953) study. The 7th and 8th levels are now being developed. The shaft is inclined 55 degrees SE., and the working levels are 250 feet vertically apart. The levels are connected by inclined raises. Sublevels, roughly parallel to and about 30 feet above the main haulage levels, extend the length of the mine. In previous workings the sublevels were driven in the ore body, but at the north end of the 6th level and in the 7th and 8th levels the sublevels are in the footwall at or near the footwall-ore contact. (Klemic and others (1959)) “The Scrub Oaks mine has been a large producer of iron ore since 1934 and during World War II its output exceeded that of any other mine in the State. In 1949 it yielded 597,031 tons of crude ore and 206,444 tons of concentrate.” (Sims (1953)) “The principal minerals of the deposit are quartz, magnetite, hematite, albite, oligoclase, perthite and antiperthite. Xenotime and doverite aggregates and bastnaesite with intermixed leucoxene are the most abundant rare-earth minerals, and zircon, sphene, chevkinite, apatite, and monazite are of minor abundance in the ore. The rare-earth elements are partly differentiated into cerium-rich bastnaesite, chevkinite, and monazite, and yttrium-rich xenotime and doverite. Apatite, zircon, and sphene contain both cerium and yttrium group earths.” (Klemic and others (1959)) “The ore deposits in albite-oligoclase granite gneiss differ from the other ore types in several respects. The largest deposit of this type, and the only one now being mined, is the Scrub Oaks ore body. In this deposit the ore minerals form finely disseminated grains and, less commonly, irregular veinlets and lenses. Quartz and albite are the principal gangue minerals; apatite is sparse. The average tenor of the ore now being mined is about 27 percent iron and 0.075 percent phosphorus. Because of the low phosphorus content the ore, after concentration, is of Bessemer grade.” (Sims (1953))

Recorded production

• Scrub Oaks, Scrub Oaks Mine: produced 187,000 metric tons of iron (Fe), containing about 187,000 metric tons Fe, 1949–1949 (Sims (1953), Page 298)

Exploration and site history

• Active — The mine opened in 1856; Not worked extensively until WWI when it was acquired by Alan Wood Steel Co., 1856–1957 (Sims (1953))
• Exploration — A deposit of rare-earth minerals in the Scrub Oaks iron mine, Morris county N.J., was mapped and sampled in 1955, 1955 (Klemic and others (1959))
• Discovery — A deposit of radioactive rare-earth minerals in the Scrub Oaks mine was disclosed in 1954; Found on the 5th level of the mine by Charles Weiler & Edward Osetek; Specimen was given to the senior author and analyzed in the U.S. Geol. Survey laboratories, 1954 (Klemic and others (1959))

Record imported from USGS USMIN ver. 4.0 (June 2019). Developments after that date appear on facility records, not here; see the methodology.