CHAPTER VI.

THE WORK OF THE OCEAN.

Volume and composition, 324. Topography of bed, 326.

Distribution of marine life, 328.

+Processes in Operation in the Sea+ 329

Diastrophism, 329. Vulcanism, 332. Gradation, 333.

+Movements of the Sea-water+ 334

Differences in density and their results, 335. Differences in

level and their results. 335. Movements generated by 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 horizontal

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-water 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 constituents 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.

Geology, Vol. 1 [of 3] · 第 6 / 22 章