Fig. 10.---Plot of conglomerate clast composition versus stratigraphic position for the Usibelli Group and the Nenana Gravel. Note that quartz, schist, and metasedimentary clasts are most common low in the section, whereas sandstone/conglomerate and plutonic/greenstone clasts are more abundant higher in the section. Circles on the left side of the figure mark the stratigraphic position of the 36 conglomerate clast counts used to construct this diagram. Total number of clasts counted = 3420.