| Basis for focus area |
Series of potassic, Fe-enriched plutons somewhat coeval with Wolf River Batholith, dated at ~1565 Ma. Stettin nepheline syenite pluton is a REE entry in USMIN. Fluorite, REE-bearing minerals, and pyrochlore found in pegmatites cutting the Nine-Mile pluton. |
| Identified resources |
Unknown. |
| Production |
Unknown. |
| Status |
Unknown. |
| Estimated resources |
No data. |
| Geologic maps |
Sims (1992), scale 1:500,000; LaBerge and Myers (1983), scale 1:100,000. |
| Geophysical data |
Inadequate aeromagnetic and aeroradiometric coverage. |
| Favorable rocks and structures |
The Wausau Syenite Complex consists of 4 intrusion. From oldest to youngest these are Stettin complex, Wausau pluton, Rib Mountain pluton, and the Nine Mile pluton. The Stetten intrusion is the most alkaline, and pegmatites carrying fluorite REE-bearing minerals and pyrochlore cut nepheline syenite. Pegmatite dikes cutting the Nine-Mile pluton carry REE minerals, including monazite, xenotime, bastnasite, and pyrochlore-group minerals, as well as abundant fluorite. |
| Deposits |
Wausau area (MRDS dep_id: 10132832). |
| Evidence from mineral occurrences |
MRDS. |
| Geochemical evidence |
Hafnium, niobium, REE, tantalum, thorium, zirconium occurrences. |
| Geophysical evidence |
No data. |
| Evidence from other sources |
No data. |
| Cover thickness and description |
Partially exposed; glacial cover in some areas. |
| Authors |
Laurel G. Woodruff. |
| New data needs |
New geologic mapping, high resolution geophysics. |
| Geologic mapping and modeling needs |
Need new geologic mapping. |
| Geophysical survey and modeling needs |
High resolution aeromagnetic and aeroradiometric coverage needed and more ground gravity data for Marathon County. |
| Digital elevation data needs |
Lidar planned; currently inadequate. |
