MOVEMENTS AND DEFORMATIONS OF THE EARTH'S BODY. 589 



which occur at long intervals and mark off the great eras of geologic 

 histor^^ These great deformations apparently involve the whole, or 

 a large part, of the body of the earth, and seem to require a very high 

 state of effective rigidity. 



General references on crustal movements. — Babbage, Jour. Geol. Soc, Vol. Ill 

 (1834), p. 206; Lyell, Principles of Geology, Vol. II, p. 235; Mallet, Phil. Trans. (1873), 

 p. 205; Reade, Origin of Mountain Ranges, and Evolution of Earth Structure; Fisher, 

 Physics of the Earth's Crust; Dutton, Greater Problems of Physical Geology, Bull. 

 Phil. Soc. of Washington, Vol. XI, p. 52, also Amer. Jour, of Sci., Vol. VIII (1874), 

 p. 121, and Geology of the High Plateaus of Utah (1880); Jamieson, Quar. Jour. Geol. 

 Soc. (1882), and Geol. Mag. (1882), pp. 400 and 526; Heim, Mechanismus der Gebirgs- 

 bildung; Marjerie and Heim, Les Dislocations de I'Ecorce terrestre (1888); Shaler, 

 Proc. Boston Soc. Nat. Hist., Vol. XVII, p. 288; Dana, Manual of Geol. , 4th ed. , p. 345 

 et seq.; Woodward, Mathematical Theories of the Earth, Smithsonian Rept. for 1890, 

 p. 196; Willis, The Mechanics of the Appalachian Structures, 13th Ann. Rept. U. S, 

 Geol. Surv., Pt. II (1893), pp. 211-282; LeConte, Theories of Mountain Origin, Jour. 

 Geol. Vol. I (1893), p. 542; Gilbert, Jour. Geol., Vol. Ill (1895), p. 333, and Bull. 

 Phil. Soc. of Washington, Vol. XIII (1895), p. 31; Van Hise, Earth Movements, Trans. 

 Wis. Acad. Sci., Arts and Let., Vol. II (1898), pp. 512-514; Estimates and Causes of 

 Crustal Shortening, Jour Geol., Vol. VI (1898), pp. 29-31; Relations of Rock Flowage 

 to Mountain Making. Mon. XL VII, U. S. Geol. Surv. (1904), pp. 924-931; A. Geikie, 

 Text-book of Geology, 4th ed. , pp. 672-702. 



