PASTURE CULTURE 5 



The last geological event of major significance which strongly affected the 

 character of Massachusetts soils was the spreading of vast ice sheets over the 

 whole of New England during a comparatively recent Ice Age. Great ice masses 

 moving over the State in a southerly direction scoured rock and soil surfaces to 

 carry along great quantities of heterogeneous materials ranging from fine clay 

 through sand and gravel to huge boulders. After the melting of the ice, these 

 materials were left as an irregular veneering over most of the State's surface. 



According to W. J. Miller, "Most of the deposits made during the ice advance 

 were obliterated by ice erosion, but those formed during the ice retreat have been 

 left practically intact except for the small amount of post-glacial erosion."^ As a 

 result, the land surface of most of Massachusetts is that of a typical glaciated 

 country. A mantle of unsorted glacial till covers the more level areas. Well- 

 sorted outwash materials occur along valley walls and on valley floors, while old 

 glacial lake beds yield considerable deposits varying in phj'sical character and 

 depth. 



The presence of hundreds of small lakes and the occurrence of many bogs and 

 marshes indicate a condition of imperfect and haphazard drainage, and this is 

 typical of recenth" glaciated country. Other formations peculiar to glacial action 

 also occur, among the most important being the many low, elongated, distinctively 

 rounded hills called drumlins, which are widely distributed over the State. 



This wide variety of glacial formations and remains has given rise to the develop- 

 ment of equally variable soils. Because glaciation was relatively recent, these 

 soils are young and the profiles are comparatively immature; hence they are 

 much influenced by the parent rock material from which they have been derived. 

 Thus may be attributed to the glacier the necessity for classifying an unusually 

 large number of soil types which differ in physical characteristics, chemical com- 

 position, and drainage conditions. 



Influence of Climate 



Cool temperatures and moderately high rainfall (40 to 45 inches annually) 

 characterize the climate of Massachusetts. Since such conditions favor the 

 development of forest trees, it is not surprising to learn from historical records 

 that a natural cover of mixed forest trees spread over the whole of Massachusetts. 

 The rich and varied character of the vegetation is indicated by an observer in 

 1775, who writes as follows: "1 should not forget the woods, which, in the parts 

 not brought into culture, are very noble; they consist of oak, ash, elm, chestnut, 

 cypress, cedar, beech, fir, sassafras, and shumac."* 



The surface of the ground in these virgin forests was covered with a thick layer 

 of organic matter or "vegetable mould," as it was first called, which was com- 

 posed of leaves of forest trees, forest undergrowth, and other forms of forest 

 debris. This layer is described by an early writer as being "fattened by the 

 continual fall of leaves from trees growing thereon" and as covering the ground 

 "to a spit's depth"^ (a "spit" was approximately cne foot). Scill another report 

 states that in Berkshire County "the first settlers feared that they would have no 

 building-material, so deeply were the stones covered by the richness of the forest 

 mould. "^ As long as a forest cover remains, this layer is continually being added 

 to on the surface, and, when not frozen, continually undergoing decomposition 

 beneath the surface. Since cool temperatures do not favor its rapid oxidation, 

 the accumulative process is faster than the wasting-away process. As a result, a 



^The Geological History of the Connecticut Valley (Northampton, 1921), p. 63. 



^American Husbandry [London, 1775] (1939 ed.. New York), p. 42. 



%ew England Quarterly, IX (1936), 220. 



•■Mass. State Bd. .-Xgric. 26th Annual Report (1878), Pt. II, p. 29. 



