Scientific Investigations Report 2006–5316
U.S. GEOLOGICAL SURVEY
Scientific Investigations Report 2006–5316
DOE/ID-22201
Figure 9. Distributions of total sediment thickness among various groupings of composite units. For rocks older than unit 1, the similarity in histogram shape among various age-range groupings and the results of nonparametric tests of similarity (table 3) indicate that the amount of sediment relative to basalt has remained fairly similar over time.