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Geologic mapping of Mesoproterozoic lithologies and foliations, and sensitive high-resolution ion microprobe (SHRIMP) U-Pb crystallization ages of 43 samples of orthogneisses and metagranitoids from the northern Blue Ridge establish new subdivisions: group 1 (1183–1144 Ma), group 2 (1143–1111 Ma), and group 3 (1078–1028 Ma). Protoliths of group 1 were metamorphosed at amphibolite- to granulite-facies conditions and strongly deformed between ca. 1153 and ca. 1144 Ma. Metagranitoids of groups 2 and 3 were emplaced continually for another 115 m.y. and display only local effects of diminishing deformation events. Ages of zircon overgrowths overlap temporally with igneous crystallization ages of group 3, but continued until ca. 960 Ma.

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