Classification scheme of Size (1972) used in this paper. Red Hill complex of White Mountain Magma Series [Plutonic-Volcanic Suite] consists of six units, all of which intrude the Devonian Winnipesaukee quartz diorite. From oldest to youngest the six units are referred to as the Outer Coarse Syenite, Nepheline Sodalite Syenite, and Fire Tower Syenite, followed by plug-like bodies of Garland Peak Syenite, Watson Ledge Quartz Syenite and the Interior Fine Granite. [Garland Peak and Watson Ledge are formal names; the other subunits are informal.] Interior Fine Granite has been radiometrically dated at 188 Ma (Foland and Friedman, 1977). The Outer Coarse Syenite forms a complete ring around the other units. The Nepheline Sodalite Syenite outcrops completely within the Outer Syenite and is texturally and chemically variable. The Fire Tower Syenite is completely surrounded by the other two and intruded by the three plug-like units. Geologic map. [Red Hill and Winnipesaukee are formal names though lower-cased in this report.]

Source: GNU records (USGS DDS-6; Reston GNULEX).

Used as Red Hill Syenite of White Mountain Plutonic-Volcanic Suite. Not separately mapped on 1:250,000-scale geologic map, but shown on 1:500,000-scale derivative map of plutons and sample localities for isotopic dating. Isotopic ages are as follows:
1. 199 +/-4 Ma by K-Ar methods (Armstrong and Stump, 1971).
2. 190 +/-4 Ma by Rb/Sr methods (Foland and Faul, 1977).
3. 198.5 +/-1.5 Ma and 187.3 +/-3 Ma by K-Ar and Rb/Sr methods (Henderson and others, 1989).
Report includes geologic map, cross sections, correlation chart, and four 1:500,000-scale derivative maps.

Source: GNU records (USGS DDS-6; Reston GNULEX).