Tin in Eastern Maine

Region East, Northeast
Mineral systems
Deposit types
Other minerals

Information leading to the delineation of this focus area

Basis for focus area Devonian intrusives in similar geologic setting to formerly productive Sn mines in Nova Scotia.
Identified resources None.
Production None.
Status Exploration by Canadian company, including granitic outcrop sampling and heavy mineral stream sediment sampling in 1980s.
Estimated resources Unknown.
Geologic maps Osberg and others (1985), scale 1:500,000; Gates (1977), scale 1:62,500.
Geophysical data Inadequate aeromagnetic and aeroradiometric data: Rank 5 aeromagnetic and aeroradiometric data.
Favorable rocks and structures Lower Paleozoic metamorphic rocks intruded by several discreet Devonian granite plutons. Devonian S-type granites have potential greisen development.
Deposits No known Sn deposits in focus area, but a large Sn-bearing glacial erratic was discovered in 1972. No source has been found to date.
Evidence from mineral occurrences F.M. Beck (written commun., 2019).
Geochemical evidence Stream sediment and outcrop sampling of exposed granite plutons was conducted in 1982. Several anomalous sites were identified for additional work before the exploration was concluded.
Geophysical evidence Unknown.
Evidence from other sources Geologic similarities to productive Sn mines in Nova Scotia.
Comments It is conceivable that aeromagnetic geophysical mapping could lead to the discovery of buried calc-silicate skarn deposits within the Pioneer Mountains. Carbonate formations intruded by silicic intrusions hosting past producing Sn mines are found throughout the region. The same carbonate rocks and intrusions could occur at other unexplored locations within the Pioneer Mountain range.
Authors Fred M. Beck.
New data needs High resolution airborne geophysics.
Geologic mapping and modeling needs A more accurate location for the edges of the potentially productive plutons is needed.
Geophysical survey and modeling needs High resolution airborne aeromagnetic and aeroradiometric coverage would assist in more accurately locating the edges and tops of the plutons which are the most likely areas for tin mineralization in greisen zones.
Digital elevation data needs Lidar complete.