A foliated granitic complex in the north evolved contemporaneously with gneiss in the south. Small ultramafic bodies in both areas were emplaced before and after metamorphism. All are cut by younger dolerite dikes. K-Ar dates in the gneiss and granitics range from 2.31 to 2.78 b.y.; quartz monzonite is 2.78 b.y., and quartz diorite ranges from 2.79 to 3.14 b.y. Other miscellaneous dates are reported. The dates are minimum only, due to argon loss. The major metamorphism-metasomatism event at approximately 3 b.y. is supported by U-Pb dates on zircons and monazite.