What do the rocks say?
The Chattanooga and its correlatives are known for their almost unvarying lithology. The quartz that makes up a large percentage of the Chattanooga is uniformly fine- to very fine-grained over its entire area of preservation. There is very little size grading. Conant and Swanson (1961, p. 43-45) describe the quartz in the Chattanooga as follows: The following generalities are drawn from study of thin sections of rocks in the Chattanooga shale: (a) The chief detrital mineral grains of the massive black shale are silt-size quartz and somewhat smaller amounts of clay and mica, and these grains are well sorted…One of the most striking microscopic characteristics of the seemingly nearly massive black shale is a wellmarked lamination that results from a high degree of sorting of the grains… QUARTZ Extremely fine-grained quartz is the major constituent of the black shale beds of the Chattanooga and probably makes up about 20 to 25 percent of the rock. Partings of quartz silt are visible t
