Scrub Oaks Mine, Mine Hill, Morris County, New Jersey, USAi

Regional Level Types
Scrub Oaks Mine	Mine (Abandoned)
Mine Hill	Borough
Morris County	County
New Jersey	State
USA	Country

A major Fe occurrence/mine located in the small borough of Mine Hill, near Dover, on private land. Started before 1868 and worked until 1873 but reopened for a few months in 1880, then the summer of 1881, 1899 and finally in 1905. Some references give the date of last production as 1958 while many others say that final closure was in 1966. Owned in 1879 by the Andover Iron Company, then by Wharton Steel Company from 1907-1929. Subsequently owned by the County Concrete Corporation, Kenvil, New Jersey. The Scrub Oaks mine was the largest of the many iron mines that were once scattered across the Reading Prong highlands of northern New Jersey and adjacent areas. MRDS database stated accuracy for this location is 1,000 meters (sic) (exact location is known).

Mineralization is a Fe-REE deposit hosted in a perthite-oligoclase granite. Much drilling and analyses were performed in conjunction with the ROI # 6885 research. Local rocks include albite-oligoclase granite/microperthite alaskite.

Ore is magnetite ore. The orebody dips 55SE at a thickness of 7.62 meters and a depth-to-bottom of 60.96 meters. The orebodies at Scrub Oaks were a bit different from those typical of the region. Rather than more or less massive magnetite, lens-shaped in cross-section, but lath-shaped in length, the Scrub Oaks ores were more irregular and disseminated. The ores contained a significant amount of hematite, unlike nearly all the other ore deposits of the region. The ore was lean and included magnetite with rutile, apatite and calcite and 15% of hematite.

The most notable feature of the Scrub Oaks ores was the presence of uranium and rare earth minerals. It is the type locality of "doverite", now synchysite-(Y). Smith et al. (1960) note that the rare earth element mineral assemblages occur with pegmatite lithologies. The basic ores of the Scrub Oaks deposit are now thought to have been deposited in a back arc basin environment and metamorphosed to granulite facies during the Ottawan orogeny around 1040 Ma. The rare earth element mineral assemblage was likely superimposed on the existing ores during the period 1000 – 950 Ma, when the region was intruded by pegmatites and experienced widespread hydrothermal activity.

Workings include surface and underground openings with an overall depth of 457.2 meters. Shaft 1 was >1,500 feet (ca. 457 m) deep; shaft 2 was greater than 350 feet (ca. 107 m) deep and filled in with rock & soil. The mining method employed was shrinkage stoping.

Production was 3,713,932 tons of magnetite ore during the period 1856 to 1950.

Reserves and resources data:

In-situ (estimate year = 1958): Demonstrated reserves: 33,392 metric tons of ore; Measured: 33,392 metric tons; Total resources: 33,392 metric tons of ore. Fe at 30 weight percent Fe.

In-situ (estimate year = 1959): Demonstrated reserves: 9,072 metric tons of ore; Indicated: 9,072 metric tons of ore; Total resources: 9,072 metric tons of ore. REE at 3.3 weight percent.

Other Databases

Link to USGS MRDS:	10021748
Link to USGS MRDS:	10174971

Other Regions, Features and Areas containing this locality

References