Dark greenish, very fine-grained cherty tuff that grades into greenish-gray radiolarian chert in west-central Alaska; commonly considered part of the Innoko assemblage. Unit also contains fine- to coarse-grained crystal and lithic tuff, as well as volcanic breccia and conglomerate composed of poorly sorted clasts of mafic volcanic rocks and cherty tuff in a crystal and lithic tuff matrix. Unit includes several small bodies of slightly recrystallized limestone and a few small intrusive bodies of gabbro and diabase. Age assignment is from widely distributed Radiolaria and conodonts in the cherty beds and range in age from Mississippian to possibly as young as Jurassic (Patton and others, 1980). Unit is unique in this group of assemblages (Angayucham, Tozitna, and Innoko) because of its tuffaceous character. Unit crops out in a distinctive band east of the more typical Innoko terrane rocks. Unit is similar in age and lithology to unit JTrct of the Chulitna sequence, but there is little reason to assert that these are the same unit