xii CONTENTS. 



PAGE 



winds, 336. Movements generated by attraction, 322. 

 Aperiodic movements, 338. Summary, 339. 



Waves 339 



Wave-motion, 339. 



Work of the Waves 342 



Erosion 342 



By waves and undertow, 342. 



Topographic Features Developed by Wave Erosion. . . . . 349 



The sea-cliff, 349. Chimney rocks, etc., 350. Sea caves, 

 350. The wave-cut terrace, 351. Wave erosion and hori- 

 zontal configuration, 353. 



Transportation by Waves , 354 



Deposition by Waves, Undertow, and Shore Currents 355 



The beach, 355. The barrier, 356. The spit, the bar, 

 and the loop, 357. Wave-built terraces, 363. 



Effect of Shore Deposition on Coastal Configuration 363 



Summary of Coastal Irregularities 364 



The Work of Ocean-currents 366 



Deposits of the Ocean-bed 368 



Shallow-ioater Deposits 369 



Littoral deposits, 369. Non-littoral, mechanical deposits 

 in shallow water, 369. Characteristics of shallow-water 

 deposits, 373. Topography of shallow-water deposits, 374. 

 Chemical and organic deposits, 375. Limestone, 378. 



Deep-sea Deposits 378 



Contrasted with shallow-water deposits, 378. Sources, 

 380. Mechanical inorganic deposits, 380. Organic con- 

 stituents of pelagic deposits, 382. Chemical deposits, 383. 



Lakes 386 



Changes taking place in lakes, 387. Lacustrine deposits, 

 388. Extinct lakes, 388. Lake ice, 389. Saline lakes, 391. 

 Indirect effects of lakes, 392. Composition of lake waters, 

 392. 



CHAPTER VII. 

 THE ORIGIN AND DESCENT OF ROCKS. 



Composition of Igneous Rocks 395 



Leading elements, 396. Union of elements, 397. Forma- 

 tion of minerals, 397. Sources of complexity, 398. The 



