Dominantly medium- to medium-dark-gray garnetiferous quartz-mica schist and amphibolite, but includes slate and shale in the Livengood quadrangle. Locally has gneissic texture. Minor white to light-gray, medium- to coarse-grained, thin- to medium-bedded, typically finely laminated marble and very minor quartzite occurs in the Tanana quadrangle. Unit outcrops as large fault slivers or “lozenges” along a strand of the Tintina-Kaltag Fault System in the Livengood (Weber and others, 1992) and Tanana quadrangles (Reifenstuhl and others, 1997). In the Tanana quadrangle, geophysical interpretation cited in Reifenstuhl and others (1997) and outcrop patterns suggest a steep northwest contact with rocks of the Tozitna assemblage and a moderately southeast-dipping southeast contact. Protolith age is unknown and, although Reifenstuhl and others (1997) and Dusel-Bacon and others (1989) suggest a Ruby or Yukon-Tanana metamorphic complex origin, Weber and others (1992) suggest a possible protolith of Tozitna sedimentary rocks (see section on the Angayucham, Tozitna, and Innoko assemblages and Rampart Group (unit KMm) and included subunits). Includes the Raven Creek Hill unit of Weber and others (1992) and units pTam, pTas, pTaq of Reifenstuhl and others (1997). Also includes light- to medium-gray, fine-grained, recrystallized sucrose-textured, hard, dense, cryptically layered quartz arenite interbedded with the pelitic schist unit. Exposures are rare and typically consist of blocky, black lichen-covered talus. A black opaque mineral composes as much as 3 percent of the quartzite. Quartzite unit is uncommon and differentiated where possible