264 GEOLOGY OF THE ISLE OF WIGHT. 



nature of the laud, and its fauna and flora, may be 

 necessary to enable the unscientific reader justly 

 to appreciate the geological interest of the pheno- 

 mena that will demand his notice — phenomena 

 which, if rightly interpreted, will reveal a former 

 condition of the earth's surface, more marvellous 

 than any which even the wildest imagination has 

 ventured to portray. 



Nature of river deposits. — The torrents that 

 rush down the mountains' sides, and the streams 

 and rivulets that meander through the plains, are 

 more or less charged with earthy particles, worn 

 from the rocks and strata over which the waters 

 flow ; and the united streams, in their progress to- 

 wards the rivers, become more and more loaded with 

 adventitious matter, and a great quantity of de- 

 tritus is mechanically suspended in the water, and 

 carried towards the sea. If the current is feeble, 

 and the inclination of the ground but slight, a 

 large proportion of the mud, pebbles, and gravel, 

 subsides in the bed of the river ; but the greater 

 part is transported to the mouth of the stream, 

 and accumulating in the bays and creeks, and 

 around the embouchure of the river, gives rise 

 to those deposits of alluvial debris termed 

 deltas and estuaries. But the finest particles of 

 the detritus are carried far out to sea, by the 



