Metaconglomerate (Kreisa, 1980). Metamorphosed sandy conglomerate, conglomeratic sandstone, and granule conglomerate containing pebbles and cobbles of polycrystalline quartz, with lesser diorite, diabase, chert, rhyolite, granite, schist, and quartz arenite. Cobbles are generally less than 2 cm but may range up to 25 cm in diameter (Kreisa, 1980). Unit occurs as beds of 0.3 to 6.1 meters thickness at base of and locally within the lower portion of Aaron section. Aaron slate (Zas) and metaconglomerate (Zac) herein includes the upper and lower members of the Aaron Formation of Kreisa (1980), and the Aaron Formation and upper portion of the Virgilina Formation of Harris and Glover (1985).