National Uranium Resource Evaluation, Portland Quadrangle: Maine and New Hampshire
The two-mica granite of the Sebago Lake pluton (New Hampshire plutonic-volcanic series) is classified as an environment favorable for the occurrence of uranium deposits containing not less than 100 tons U/sub 3/O/sub 8/ at an average grade of at least 100 ppM U/sub 3/O/sub 8/. The granite is abnormally differentiated relative to uranium: the uranium-to-thorium ratio varies from about 1:4 in facies having less than about 15 ppM U/sub 3/O/sub 8/ to greater than 6:1 in zones bearing up to more than 500 ppM U/sub 3/O/sub 8/. Radioactivity in the granite increases with grain size in uraniferous zones, reaching maxima in pegmatoid facies. Along fractures in these zones, uraninite, microcline, apatite, and molybdenite were introduced by mineralizing deuteric fluids. Red staining of K-feldspar is due to radioactive bombardment and secondary hematite. Introduction of secondary hematite is not necessarily related to uranium enrichment. The southern portion of the White Mountain batholith, composed of the Conway and Mt. Osceola Granites, is classified as a favorable environment for uranium deposits, although no favorable areas were identified. The Conway Granite contains up to 37 ppM U/sub 3/O/sub 8/ in deuterically altered miarolitic zones and up to 28 ppM U/sub 3/O/sub 8/ in the unaltered portions. The granite apparently has not been significantly differentiated relative to uranium. Nonetheless, concentrations of U/sub 3/O/sub 8/ up to about 100 ppM were found at one locality in a biotite-rich zone and at another along a quartz-epidote vein. The vein is similar to veins associated with the miarolitic zones of deuteric alteration.
- Research Organization:
- Bendix Field Engineering Corp., Grand Junction, CO (USA). Grand Junction Operations; Chiasma Consultants, Inc., South Portland, ME (USA)
- DOE Contract Number:
- AC13-76GJ01664
- OSTI ID:
- 5297465
- Report Number(s):
- PGJ/F-028-82; ON: DE82018995
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
DATA ANALYSIS
EVALUATION
FEDERAL REGION I
GEOLOGIC DEPOSITS
GEOLOGICAL SURVEYS
GEOPHYSICAL SURVEYS
GRANITES
IGNEOUS ROCKS
MAINE
MINERAL RESOURCES
NEW HAMPSHIRE
NORTH AMERICA
PLUTONIC ROCKS
RESOURCES
ROCKS
SURVEYS
URANIUM DEPOSITS
USA