Geology of Hudson County, Xcic Jersey. 55 



Nearly the whole of the main upland of Hudson Connty, from 

 the Kill Von Knll to Bnll's Ferry road, is covered with glacial 

 drift soil. Its characteristic features are well shown at Bergen 

 Point, along the line of the JST. J. Central Eailroad, and at the 

 railroad cuts and street excavations in various parts of Bergen 

 Hill and Weehawken: the depth of the drift in these exposures 

 varies from a few inches to twenty or thirty feet. 



Eastward of Bei'gen Hill, the glacial drift soil occurs at Con- 

 stable's Point, Caven Point, Communipaw, and Lafayette; also 

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

 viz. Paulus Hook, Harsimus, and Pavonia, and on the similar 

 area northward of these around the serpentine hill forming Castle 

 Point. At all these localities the reddish glacial drift, with its 

 boulders, etc., is largely covered by blown sand, which forms 

 our third division of soils. 



The amount of clay which these soils contain makes them less 

 retentive of moisture, and therefore less desirable from a sanitary 

 point of view, than more sandy and porous strata. This ten- 

 dency to retain the surface water is counteracted in some portions 

 of Hudson County by the slope of the underlying rocks, which 

 secures a good natural drainage. 



This is the case on the western slope of Bergen Hill, and also 

 on some portions of Bergen Neck and Bergen Point, where 

 the drainage is to the eastward. Over a large area on the 

 top of Bergen Hill, however, where the trap-rock has been worn 

 down by glacial action to an irregular plane surface, the cover- 

 ing of drift fills the depressions in the rocky floor beneath, and 

 thus forms a soil, not only stiff and retentive, but also Avitli an 

 incomplete or in many cases total lack of drainage ; this region, 

 I understand, has long been known to resident phj'sicians as 

 one where malarial diseases particularly prevail. In some cases, 

 wells have been sunk through the covering of drift on Bergen 

 Hill, and a supply of water obtained from some of these con- 

 cealed sink-holes, thus greatly endangering the health of those 

 using the Avater. In West Hoboken and Weehawken, several of 

 these depressions in the trap — some of them receiving the drain- 

 age from considerable areas — may be seen ; they are now in the 

 condition of lakelets or marshes filled with decaying vegetable 

 matter, which become partially dried in the summer, and cer- 



