[194] Average of two analyses.

[195] As sesquicarbonates.

[196] As chloride.

[197] As peroxide.

[198] Carbonic acid by difference.

[199] Analyses of Rocks, Bull. 168, U. S. Geol. Surv., 1900, p. 15.

[200] Quantitative Classification of Igneous Rocks, by Whitman Cross, Joseph p. Iddings, Louis V. Pirsson, and Henry S. Washington. 1903.

[201] Van Hise. 16th Ann. U. S. Geol. Surv., Pt. I, pp. 589–94.

[202] The application of these principles we owe chiefly to Van Hise: Metamorphism of Rocks and Rock Flowage, Bull. Geol. Soc. Am., Vol. 9, pp. 269–328.

[203] Cross, Iddings, Pirsson, and Washington. Quantitative Classification of Igneous Rocks.