Triassic carbonaceous cherts are widesp-read in the Sikhote-Alin fold belt. They occur in a 4 to 20 m-thick sequence of interbedded cherts, carbonaceous cherts, and argillites that ranges in age from Upper Olenekian to Upper Anisian. The carbonaceous cherts are marine radiolarian rocks that contain 0.3 to 8.5 wt% C
. The majority of these rocks have undergone textural and mineralogical changes to a middle stage of catagenesis. Their organic matter contains low-grade oxidized humic acids with quinone, >CH
hydrocarbon groups. The δ
C values are between −27.3 and −32.5 ‰. Carbonaceous cherts are anomalously enriched in V, B, Cu, Ni, Mo, Ag, and locally Au.