LOWER SILURIAN SYSTEM OF EASTERN MONTGOMERY CO. 43 1 



man station. South of the Mohawk the Calciferous sandstone 

 appears in low ledges along the greater part of its outcrop. The 

 Trenton limestone produces a gentle topography with scarcely any 

 ledges or sharp lines. 



The second region, that of the Utica shale, is characterized by 

 rounded hills rising at Iheir maximum to an altitude of 1062 feet 

 A.T. or about 800 feet above the Mohawk river. Here again there 

 are no deep glens. The formation is very homogeneous, there 

 being few hard layers to form waterfalls or steep slopes by the 

 more rapid disintegration of underlying shale. The highest parts 

 of this region are near the parting of the Utica and Hudson river 

 shales. After the removal of the latter formation the Utica shales 

 are rapidly reduced to base level. 



The third region, that of the Hudson river formation, furnishes 

 by far the most interesting topography, being characterized by bold 

 relief; the very soft shales interstratified with firm layers of sand- 

 stone produce an abundance of deep and very narrow glens and 

 steep hillsides. Waterstreet hill back of Rotterdam Junction rises 

 to an altitude of 1400 feet A.T._, nearly 1000 feet above the level 

 of the Mohawk river. Its northern slope is steep and with the 

 southern slope of the Glenville hills across the river forms the 

 Notch, so conspicuous a feature of the northwestern horizon from 

 the vicinity of Schenectady 10 miles to the east. Eastward the hill 

 plunges abruptly to the bed of the Plotterkill, forming one of the 

 finest glens in the eastern part of the state. The streams empty- 

 ing into the Mohawk in Rotterdam township form a series of beauti- 

 ful and characteristic waterfalls. Almost every heavy sandstone 

 layer has its fall. Normankill in the southern part of this region 

 flows for the greater part of its course in a deep narrow valley 

 often amounting to a gorge with precipitous sides. This stream, 

 it will be noted, empties into the Hudson river near Albany. The 

 divide between the Mohawk and Normankill drainage reaches an 

 altitude of over 1400 feet A.T. and extends with little variations 

 from this amount through Rotterdam, Princetown and Duanes- 

 burg townships. It will be seen that Mariaville pond and Feather- 

 stonaugh lake are situated only 100 feet below the summit of the 

 divide which is less than half a mile south of the latter. 



The hills of these Hudson river strata rise abruptly along the 

 Hudson-Utica parting. The valley of South Chuctanunda rapidly 



