Figure 1
From: Biogenically induced bedded chert formation in the alkaline palaeo-lake of the Green River Formation
Location map, division of lacustrine paleonenvironments, lithostratigraphic columns, and outcrop photographs of the bedded chert succession in the Green River Formation. (a) Location map of the Green River Formation in the Indian Canyon section, western Uinta Basin. (b) Lithostratigraphic column, chert occurrences, and subdivision of lacustrine palaeoenvironments; 40Ar/39Ar ages of intercalated tuffs are from Smith et al.26 O: Oily tuff; P: Portly tuff; F: Fat tuff; W: Wavy tuff; C: Curly tuff. (c,d) Outcrop photographs and lithological columns of alternating beds of chert, dolomite, and mudstone. Occurrences of chert beds represent marked periodicities of centimetre-scale changes in thickness. All photographs (c,d) shown here are taken by R. Kuma.
