Secondary uranium mineralization occurs in a northwest-trending fracture zone in the Devonian Concord Granite in recent rock cuts along Interstate Highway 89 near New London, New Hampshire. A detailed plane table map of this occurrence was prepared. Traverses using total gamma ray scintillometers throughout the pluton of Concord Granite identified two additional areas in which very small amounts of secondary mineralization occurs in the marginal zones of the body. All three areas lie along the same northwest trend.
A ground radiometry survey of a large part of the Jurassic White Mountain batholith was conducted. Emphasis was placed on those areas from which earlier sampling by Butler (1975) had been done. No unusual geological characteristics were apparent around sample localities from which anomalous U and Th had been reported.. The results of this survey confirm previous conclusions that the red, coarse-grained, biotite granite phase of the Conway Granite is more radioactive than other phases of the Conway Granite or other rock types of the White Mountain Plutonic-Volcanic Series. Aplites associated with the Conway Granite were found .generally to be as radioactive as the red Conway Granite.
Additional publication details
USGS Numbered Series
Selected uranium and uranium-thorium occurrences in New Hampshire
U.S. Geological Survey,
ii, 42 leaves,  leaf of ill. :ill., maps (1 fold.) ;27 cm.; (43 p., 2 sheets - PGS)