258 EECENT FORMATIONS. 



larger rivers. "We take, for example, Stratheden in Fife 

 (locally the " Howe " or hollow of Fife), and there, within 

 a distance of twenty miles, we have first the sand-banks 

 and sand-drift now in course of formation along the outer 

 estuary; a few miles inland a greyish " carse-clay," with 

 antlers of deer and bones of oxen, overlying a peaty layer 

 of forest-growth replete with the stumps and trunks of 

 the oak, pine, hazel, alder, birch, and willow, marking an 

 oscillation of the land;* and still further up the strath, 

 extensive deposits of sand and brick-clay, containing the 

 remains of whales, seals, northern sea-birds, arctic shells, 

 and star -fishes, usually regarded as immediately post- 

 glacial. 



Of Eecent Formations, the next that fall to be con- 

 sidered are the Marine, or those accumulated in seas, and 

 whose imbedded remains are chiefly of oceanic growth and 

 habitat. Of course much of the sediment deposited in 

 the ocean is brought down by rivers from the surface of 

 the land, but we refer here to the areas in which it is col- 

 lected, and the manner in which it occurs. Marine silt 

 (mud, sand, and miscellaneous debris) is formed in every 

 sheltered bay and recess of the ocean, where, under the 

 influence of winds, waves, and tides, it gradually accumu- 

 lates till it banks out the water, and is converted into 

 tracts of low-lying alluvial land. The fens of Lincoln, 

 and the polders of Holland, are familiar examples in our 

 own seas ; and as these have been formed, so have similar 

 flats along every sea -shore favoured with the necessary 

 shelter and the necessary tidal sets. In many areas it will 



* This submarine forest, which is well exposed at the railway bridge 

 across the affluent stream of the Motrie, is at the same level and of a 

 similar character with those occurring on the Tay, Forth, Humber, the 

 coast of Lincolnshire, Devonshire, Lancashire, and other localities. 



