Tarr — Origin of the Chert in the Burlington Limestone. 451 



chemical precipitate, was thrown down as colloidal silica upon 

 the sea bottom through the action of salts in the sea water. 

 The precipitation occurred contemporaneously with that of the 

 limestone or dolomite, and the silica was derived from the land 

 through ordinary processes of chemical weathering. The col- 

 loidal silica was then consolidated into the chert through pres- 

 sure, loss of water, and crystallization. 



BIBLIOGRAPHY. 



Only the more important of the articles bearing on chert are given in this 

 bibliography. A large amount of literature was examined for data on the 

 problem, but most of it has to do with the occurrence of chert rather than 

 the origin. 



Ashley, H. E. : Silica in soils, Bull. U. S. G. S. No. 388, p. 10. 



Bain, H. F. : U. S. G. S. 22d Kept., Pt. II, 106-108. 130-181. 



Bain, H. F. and Ulrich, E. 0. : U. S. G. S. Bull. No. 267, p. 27. 



Ball, S. H. and Smith, A. F. : Mo. Bur. Geol. and Min., vol. i. 2d ser., pp. 



34, 85, 145-147, 1903. 

 Bowerbank, Dr. : Trans. Geol. Soc, 2d ser., vol. vi. 

 Buckley, E. E. and Buehler, H. A. : Geology of Granby, Mo., Area, Mo. 



Bur. Geol. and Min., vol. iv, 2d ser., pp. 31-32. 

 Chamberlin, T. C. and Salisbury, E. D. : Textbook of Geology, vol. i, p. 



426. 

 Clarke, F. W. : Data of geochemistry, Bulls. 491 and 616, U. S. G. S. 

 Fultz, F. M. : Iowa Acad. Sci. Proc, vol. ii, p. 177, 1895. 

 Geikie, A. : Structural and Field Geology, p. 66. 

 Grabau, A. W. : Principles of Stratigraphy, pp. 718-720, 764. A. G. Seller 



& Co., N. Y. 

 Griswold, L. S. : Ann. Eep. Geol. Sur. Ark., vol. iii, p. 177, 1890. 

 Hatschek, Emil : Intro, to Physics and Chem. of Colloids. 

 Hinde, G. J. : Phil. Trans. Eoyal Society, vol. clxxvi, part II, p. 403, 1885. 



Geol. Mag., vol. iv, p. 435, 1887 ; ibid., vol. v, p. 241, 1888. 

 Hovey, E. O. : this Journal, vol. xlviii, pp. 401-409, 1894. Lead and zinc 



deposits of Missouri, Mo. Geol. Surv., vol. vii, part II, pp. 727-739, 



1894. 

 Hull and Hardman : Sci. Trans. Eoy. Dub. Soc, vol. i, pp. 71, 85, 1878. 

 Irving, E. D. : this Journal, vol. xxxii, pp. 255-271, 1886. 

 Jones, T. Eupert : Proc. Geol. Assoc, London, vol. iv, 1876, p. 439. 

 Jukes-Brown, A. J. and Hill, W. : Quart. Jour. Geol. Soc, vol. xlv, p. 403, 



1889. 

 Keyes, C. R. : Iowa Acad. Sci. Proc, vol. x, pp. 103-105. 1903. 

 Lawson, A. C. : 15th Ann. Eep. U. S. G. S., pp. 420-426, 1895. 

 Lee, Wallace : Geol. of Rolla quadrangle, Mo. Bur. Geol. and Min., vol. xii, 



2d ser., 1913. 

 Leith, C. K. and Mead. W. J. : Metamorphic Geology, pp. 134-135, etc. 

 Leith, C. K. and Van Hise, C. E. : U S. G. S. Monograph 52, p. 505. 

 Lindgren, Waldemar : Mineral Deposits, pp. 189, 301, etc. Prof. Paper 



U. 8. G. S. No. 43, p. 63. 

 Lyell, Sir Charles : Elements of Geology, pp. 321-322. 

 Mantell, G. A. : Wonders of Geology, vol. i, p. 306. 

 Merrill, G. F. : Rocks, Eock-Weathering, and Soils, p. 110. 

 Moore, E. S. : Jour. Geol., vol. xx, p. 261, 1912. 

 Ostwald, W. : Colloid Chemistry. 

 Penrose, R. A. F. : Ann. Rep. of the Geol. Sur. of Ark., vol. i, pp. 129-188, 



1890. 

 Pirrson, L. V. and Schuchert, Charles ; Textbook of Geology, pp. 469-497. 

 Poschel, Victor : Intro, to Chem. of Colloids. 



