Predominantly volcanic and volcaniclastic unit of red-colored lithic tuff, lithic conglomerate, graywacke, and finely laminated tuffaceous siltstone and mudstone. Also contains minor basalt to dacite flows similar to unit JTrrb, but distinct from it because of the occurrence of clasts of gabbro, serpentinite, and fossiliferous Permian(?) limestone (Csejtey and others, 1992; Clautice and others, 2001). Found only in thrust slivers in the southwestern Healy quadrangle. Unconformably overlies volcanogenic and sedimentary rocks of Triassic to Devonian age (unit TrDv). Volcanic members are predominantly calc-alkalic andesite tuff and tuff breccia, but compositions range from calc-alkaline basalt to dacite. Coarser volcaniclastic rocks are frequently calcareous and havea predominantly medium- to very coarse-grained, poorly sorted matrix that contains occasional feldspar, clinopyroxene, and hornblende crystals. Lithic clasts are predominantly mafic volcanic rock fragments altered to chlorite, hematite, and calcite. Other lithic fragments include felsic volcanic, plutonic, and metamorphic rocks. Mineral grains are monocrystalline and polycrystalline quartz. An isolated fault-bounded(?) exposure in Broad Pass (Csejtey and others, 1992) in the Healy quadrangle is included here. Lower part of this section consists of cobble to boulder conglomerate that contains clasts of green volcanic rocks and red radiolarian chert. Chert clasts have yielded Permian Radiolaria. Finer grained volcanogenic conglomerate, higher in the section, locally contains abundant Heterastridium sp., which indicate a Late Triassic, late Norian age (Csejtey and others, 1992). The uppermost part of the section is massive volcanic sandstone. No Permian source area is known for the chert clasts in this unit