No. 4.] INUNDATED LANDS. 377 



THE INUNDATED LANDS OF MASSACHUSETTS. 1 



BY PROF. N. S. SHALER OF CAMBRIDGE. 



The soils of every country owe their quality to the geo- 

 logical history of the regions in which th- lie. They 

 depend for their essential features upon the xact that they 

 are in the main composed of originally substantial rocks, 

 which by processes of decay have been reduced to a frag- 

 mentary state, and are now slowly making their way from 

 their original bedding places towards the floor of the oceans. 

 If the rocks whence a soil was derived abounded in materials 

 suitable to the needs of vegetation, the debris which they 

 afford by decay may be fertile, and thus well calculated to 

 serve the interests of man. If the deposits, however, have 

 not such a nature as will afford a nutritious earth, the fields 

 may be barren. Owing to the complicated geology of 

 Massachusetts, the character of the soils, as determined by 

 the nature of the rocks whence they have been made, is 

 exceedingly varied. This variety is enhanced by the fact 

 that in the geological yesterday this region was deeply 

 covered by a mass of moving ice, which dragged the rock 

 waste of one district over the fields of anothe , sometimes 

 accumulating the debris to the depth of hundreds of feet,, 

 again leaving the surface almost without detrital covering. 



The character of the soil-covering in Massachusetts is 

 here and there much affected by the varying ease with which 

 the water finds its way from the surface of the land to the 

 level of low tide in the ocean. One of the most important 

 effects of the glacial period is found in the embarrassment of 

 the ancient natural river drainage through the channels of 

 which the rain-water found its way to the sea. Although 

 the valleys of the ancient streams were not to any consider- 

 able extent effaced by the glacial wearing, their surfaces 



* Published by permission of the Director of the U. S. Geological Survey. 



