GeiAogij of Hudson County, New Jersey. 53 



material with huge boulders, over which the sand has drifted. 

 At Caveii Point, a repetition of these conditions may be observed. 



The upland, formed of glacial drift, containing quantities of 

 transported boulders, on which Communipaw and Lafa^^ette are 

 situated, is covered to a large extent with similar sand. 



The islands formerly known as Paulus Hook, Harsimus, and 

 Pavonia, on which the older portion of Jersey City is built, 

 have the same history as these other areas of reolian sand. 



Around the high land forming Castle Point, similar accumu- 

 lations of glacial drift covered with blown sand may be seen ; 

 the sandy region here underlies a large portion of Hoboken. 



Swamjj Deposits. — The series of geological formations in Hud- 

 son County is brought to a close by the salt meadows bordering 

 the county on the east aiad west, and still in process of accu- 

 mulation. These are formed of vegetable groAvths, making a 

 peaty mass, composed of matted stems and roots at the top, but 

 becoming more compact and showing less vegetable structure 

 at some distance below the surface ; the peat is frequently ren- 

 dered impure by silt and mud brought i)i by high tides, and in 

 places these muddy sediments predominate over the vegetable 

 matter, and form a great depth of blue clay or mud. 



Surface Geology. 



Soils may be divided according to the mode of their forma- 

 tion, into soils of disintegration and soils of transportation. 

 The former are derived from the wearing away of the rocks 

 upon which they rest, and owe their formation to the fact that 

 even the most comi3act and homogenous rocks, when subjected 

 to meteoric agencies, are in time broken up and more or less 

 decomposed. Disintegrated rock of this nature, Avith some ad- 

 mixture of organic matter or humus, forms the soil OA'er a large 

 part of New Jersey. Soils of transportation, on the other hand, 

 have resulted from the accumulation of material brought from 

 distant sources, and are influenced but little by the nature of 

 the underlying rock. As examples of soils of transportation, 

 we have river drifts, consisting of sand, gravel, alluvium, etc. ; 

 and also the earth, clay and sand filling lake-basins and estu- 



