All rock units, many fabrics, and two major faults mapped in the Hadlyme and Willimantic areas, Connecticut, are identified in a 1.45-km-deep research hole drilled at Moodus, Connecticut. Correlation of surface information and existing shallow drill-core data with the Moodus data was partially based on the description of core and cuttings from the deep hole, with supplemental chemical analyses, petrography, and a geochemical log. Rocks to a depth of 709.9 m are a mixture of quartz-diopside granofels and biotite-quartz-plagioclase schist identical to outcrops of Hebron Formation and are assigned to the Merrimack terrane. A 46.1-m section of biotite granitic gneiss...