834 



DYNAMICAL GEOLOGY. 



G. H. Darwin : Influence of Geological Changes on the Earth's Axis of Rotation, 

 Proc. Ro}'. Soc, Nov., 1876. On the Formation of Mountains and the secular cooling 

 of the earth, Nature, Feb. 6, 1879; Amer. J. Sci., III., xvii., 320, 1879. 



A. Sedgwick : On the Structure of Large Mineral Masses (Cleavage, etc), Trans. 

 Geol. Soc. of London, II., iii., 479, read March, 1835; the distinction of slaty cleav- 

 age from bedding here first brought out. — On the Classification of the fossiliferous 

 slates of North Wales, etc., Quart. J. Geol. Soc, iii., 133, 1847 ; treats anew of the sub- 

 ject of cleavage, and discusses further the general coincidence between the strike of a 

 slate and the strike of its slaty cleavage. 



W. Sharpe: On Slaty Cleavage, Quart. J. Geol. Soc, ii., 309, 1846; iii., 74, 1847; 

 includes also the subject of the distortion of fossils. 



H. C. Sorby: On Slaty Cleavage, Edinburgh, New Phil. Jour., lv., 137, 1853; Phil. 

 Mag., IV., xii., 127, 1856. Microscopical Structure of Ciystals and Rocks, see p. 769; 

 advocates the aqueo-igneous origin of granite, etc. 



John Tyndall: On the Cleavage of Slate Rocks, Phil. Mag., IV., xii., 44, 129; 

 Lecture before the Royal Institution, 1856. 



2. American. 



W. W. Mather : New York Geological Report, 4to, 1843 ; advocates the contraction 

 theory of flexures and mountain-making. Also on the Physical Geology of the United 

 States, Amer. J. Sci., xlix., 1, 284, 1845. 



W. B. & H. D. Rogers : Structure of the Appalachians, Trans. Amer. Geol. & Nat., 

 1840-42, 474 ; Am. J. Sci., xliii., 177; xliv., 359; gives full details as to facts from the 

 Appalachians, deduces the general system in their arrangement, sets forth the relation 

 of the whole to mountain-making, and attributes the effects to wave-like movements in 

 the earth's liquid interior. 



H. D. Rogers : Report on the Geology of Pennsylvania, 2 vols., 4to, 1858. 



J. D. Dana : Origin of the General Features of the Pacific and the Globe, Rep. 

 Wilkes U. S. Expl. Exped.,4to, 1849. — On Changes of Level in the Pacific, ibid., and 

 Amer. J. Sci., II., xv., 157, 1853 —Origin of Continental and Oceanic Areas (by dif- 

 ference in rate of cooling), ibid., ii., 352, 1846 ; iii., 94, 1847. — Origin of Mountains by 

 the Earth's Contraction, ibid., II., iii., 94, 176; iv., 88, 1847; III., v. and vi., 1873. — 

 Origin of the Grand Outline Features of the Earth, ibid., II., iii., 1846; 381, xxii., 335, 

 1861 ; bringing out the relation between the extent of the great oceans on the one hand 

 and their border features (that is the heights of the adjoining continental mountain bor- 

 ders, the amount of volcanic action along them, etc.), on the other, and the evolution 

 of the North American continent. 



James Halt. : Theory of Mountains, Introduction to vol. iii. of N. Y. Palaeontol- 

 ogy* PP- !- g 6, 1859; besides adopting Herschel's view as to the sinking of an area of 

 accumulating sediments in consequence of the weight, and resulting displacements, an- 

 nounces, as a general principle, that the making of a mountain range is preceded by a 

 thick accumulation of sedimentary beds over the area; attributes metamorphism to 

 "motion, or fermentation and pressure," within the material of the rock itself. 



G. L. Vose: Orographic Geology, Boston, 1866; argues against the theory of con- 

 traction; attributes metamorphic changes to "the enormous pressure generated in the 

 folding of masses of rock," the pressure being that of gravitating sedimentary beds of 

 great thickness. 



J. P. Lesley : Coal and its Topography, 12mo, Philadelphia, 1856. — Second Geo- 

 logical Survey of Pennsylvania (under Prof. Lesley as State Geologist) ; publications 

 commenced in 1875, and still in progress. 



J. M. Safford: Report on the Geology of Tennessee, 8vo, 1st ed. 1856; 2d, 18i9; 

 treats of the Appalachian region in Eastern Tennessee. 



T. S. Hunt: Seat of Volcanic Action, Geol. Mag. 1869, and Am. J. Sci., II., 1., 21, 

 1870, and Geol. Mag., Feb., 1868; places this seat in a "plastic zone" made by the 

 " aqueo-igneous fusion " of part of the lower section of the sedimentar}' strata. — Points 

 in Dynamical Geology, Am. J. Sci., III., v., 1873. See, also, p. 770. 



