| Basis for focus area |
Buffered point around the deposits. |
| Identified resources |
Historical production of cadmium, iron, and zinc. |
| Production |
The Sterling Hill mine began operating around 1739 and produced more than 11 million tons of Zn over its 247-year lifespan. The Scrub Oaks mine, which contained magnetite (Fe) and apatite (REE) ores formed by pegmatitic overprinting of volcanogenic seafloor deposits, produced intermittently until 1905; final closure in 1966 with an estimated total production of 7 million tons of iron ore. |
| Status |
Past mining. The Sterling Hill mine is currently a museum on the National Register of Historic Places listings in Sussex County, New Jersey. |
| Estimated resources |
Unknown. |
| Geologic maps |
Drake and others (1996), scale 1:100,000; Volkert and Monteverde (2013), scale 1:24,000. |
| Geophysical data |
Inadequate Rank 3 aeromagnetic and aeroradiometric coverage. |
| Favorable rocks and structures |
Proterozoic Franklin Marble in the Reading Prong Highlands. Rocks were metamorphosed to granulite grade during the Mesoproterozoic Ottawan orogeny (~1045 to 1024 Ma). |
| Deposits |
Sterling Hill mine (MRDS dep_id: 10198715), Franklin mine (MRDS dep_id: 10073174), Scrub Oaks mine (MRDS dep_id: 10021748; USMIN Site ID: NJ00006). |
| Evidence from mineral occurrences |
MRDS; USMIN. |
| Geochemical evidence |
Major zinc minerals (zincite, franklinite, and willemite) are oxides, not sulfides. |
| Geophysical evidence |
No anomaly. |
| Evidence from other sources |
See Volkert and others (2010). |
| Comments |
Known past producer but limited spatial extent. Benefit of geophysical surveys not known. Ore is hosted in a perthite-oligoclase granite. Drilling and analyses were performed in conjunction with USBM research (Williams, 1967). The Sterling Hill and Franklin zinc deposits are Basin brine mineral system, MVT-type deposits that were highly deformed and metamorphosed to granulite grade. |
| Cover thickness and description |
Cover less than 100 m? |
| Authors |
Anjana K. Shah, Bernard E. Hubbard, Nora K. Foley. |
| New data needs |
Detailed mapping of deposits, geophysics. |
| Geologic mapping and modeling needs |
1:24,000 scale mapping of area around deposits. |
| Geophysical survey and modeling needs |
High resolution aeromagnetic and aeroradiometric coverage. |
| Digital elevation data needs |
Lidar complete. |
