Abstract

Seven mappable lithologic units are recognized: a southern gneiss terrane of plagioclase-quartz gneiss, augen gneiss, amphibolite, and a quartz-diorite body; and a northern granitic terrane of intergradational, scattered bodies of quartz monzonite, quartz diorite, and agmatite. Regional synformal structures with steep dips are defined by foliation in both terranes; with local exceptions, contacts between rock units are broadly parallel to regional strike of foliation -- E-W, E-NW, and NE-SW. Many rock units are transgressed by limited shear zones and marked by retrograde metamorphism as well as faults. The northern granitic complex evolved essentially contemporaneously with the southern gneiss during a period of metamorphism and metasomatism; late mobility of potash at the north end converted the gneiss there to granitic rocks. The isolated Bald Mtn. area may represent the center of such metasomatic activity.

First Page Preview

First page PDF preview
You do not currently have access to this article.