Most common lithologies are granitic to trondhjemitic orthogneiss and lesser amphibolite. Includes quartz-biotite ± garnet gneiss, amphibolite, and minor pelitic gneiss, quartzite, schistose gneiss, augen gneiss, and quartz-mica schist (Weber and others, 1978; Foster, 1992; Dusel-Bacon and others, 2006). Unit is most extensive in the northern Alaska Range in the Tanacross quadrangle and sparsely exposed in the Yukon-Tanana Upland. Largely metamorphosed to amphibolite facies (Dusel-Bacon and others, 1993), locally unit has been retrograded to greenschist facies in the Mount Hayes quadrangle (Nokleberg and others, 1992a). Whole-rock trace-element data indicate a within-plate origin for most amphibolite (Dusel-Bacon and Cooper, 1999). Where possible, augen gneiss mapped separately as unit MDag. This unit is gradational with unit |<ygs, which is largely of metasedimentary origin, but includes some metaigneous components