Original published in D.F. Merriam, ed., 1964, Symposium on cyclic sedimentation: Kansas Geological Survey, Bulletin 169, pp. 1-20

Figure 3--Thin section of Florissant lake deposits showing short series of normal diatomite-sapropel varves interrupted by pumice layers. Upper band contains 11 normal layers; middle band 12; and lower band 7 (X 16).