132 



and boulders of all sizes, the last all of trap, granite, and other 

 non-calcareous metamorphic rocks, such as are found in place 

 on the mainland not far away. Those less than a foot in diameter 

 are pretty well rounded by the action of ice or water during the 

 Glacial Period. 



The commonest type of soil is a brown loam plentifully sup- 

 plied with pebbles and cobbles. It is called "Miami stony 

 loam" in the soil surv'ey of western Long Island published by 

 the U. S. Bureau of Soils in 1905, in which the following physical 

 analysis is given of a sample taken two miles east of Flushing. 

 This represents only the "fine earth," the pebbles exceeding 

 two millimeters in diameter having been sifted out. The figures 

 in the first column indicate the diameters of the soil particles, 

 and the others percentages. 



Soil Subsoil 



0-14 In. 14-36 In. 



Gravel, 2-1 mm 1.72 1.78 



Coarse sand, 1-.5 mm 4.96 5.50 



Medium sand, •5-.25 mm 3.86 4.14 



Fine sand, .25-1 mm 8.28 8.58 



Very fine sand, .1-.05 mm 20.48 22.90 



Silt, .05-005 mm 43.36 4440 



Cla5% .005-.0001 mm i7-40 12.70 



Organic matter 3.06 1.16 



Total 103.12 101.16 



The soil and subsoil do not dift'er much, which probably indi- 

 cates that the soil has undergone very little weathering since it 

 was deposited by the glaciers. No chemical analyses are avail- 

 able, unfortunately, but the principal minerals in the soil are 

 said to be feldspar, muscovite and biotite mica, hornblende, and 

 quartz. These and the large percentage of silt, clay, and organic 

 matter indicate a soil well above the average in fertility. It is 

 rather impervious to water, as shown by the occurrence of 

 swampy pools near the tops of some of the hills. 



Few of the pebbles and smaller boulders appear on the surface 

 in undisturbed areas, probably on account of the activities of 

 earthworms, which abound in this type of soil. The rocks too 

 large to be buried by the worms are not large enough to support 

 any vegetation other than a few mosses and lichens, and the 



