Massive Crystalline Rocks. 165 



the end of the section to fine-grained ; and then, in three-fourths 

 of a mile, the rock is well-characterized norite. Moreover, the 

 norite contains a band of magnetite, exposed in a working (near 

 Mrs. Murden's) with which occur garnet and fibrolite. The band is 

 bedded, the magnetite is chloritic, and the assemblage of minerals 

 is the same that occurs in the soda-granite, as well as the schist 

 west of Cruger's. Fibrolite is found also with the magnetite of 

 Eastern Cortland. 



The norite and chrysolitic rocks are thus apparently in the same 

 category with the soda-granite and quartz-diorite. 



Stony Point. — This conclusion is further sustained by the facts to 

 be observed at Stony Point, and these facts come into this place, 

 although the locality is on the west side of the Hudson ; for the 

 Cruger schists make the south border of the region precisely as 

 near Cruger's, and have the same strike and dip, showing a 

 like relation to the Cruger limestone belt and proving its former 

 extension across the I'iver. For further comparison between the 

 geological facts of the east and west sides of the river, it is to be 

 observed that the succession of rocks west of Cruger's, on the line 

 going northward, from the river on the south side of the point to 

 the north side of Montrose Point, is (1) limestone; (2) schist; (3) 

 soda-granite (with some included diorite) ; (4) chrysolite rocks ; (5) 

 (on Northern Montrose Point) norite and chrysolitic rocks in 

 complicated combination. 



The same is the order on Stony Point, except that the limestone 

 is not in sight (no doubt because submerged) ; it is : (2) schists ; 

 (3) soda-granite ; (4) chrysolite rocks, followed by (o) norite and 

 chrysolite rocks combined. (The diorite of the Cruger soda-granite 

 is not represented there.) On the map, x is the area of the schists ; 

 y, the soda-granite; z, the chrysolitic rocks, and 25' the latter with 

 norite. But besides being the same in order, there is evidence that 

 the soda-granite succeeds the schist along a plane of bedding of 

 the schists, as if conformable^ This is apparent at the junction of 

 the two on the east-north-east shore of the point. Included beds of 

 schist occur, but the covering of earth prevents a determination of 

 their direction. Further, the chrysolitic rocks succeed to the soda- 

 granite along a plane parallel to the same plane of bedding, as is 

 seen just west of the boat-pier near the middle of the northern 

 shore. Besides these facts, there are included beds of fine-grained 

 hornblende rock (schist ?) and other kinds in the norite and chrysolitic 

 rocks, which are in general conformable to the same plane, or about 

 N. 70° E. in strike, with a dip of 75° to 80° to the northward. 



Such facts sustain the inference as to the former connexion of 

 the rocks of the east and west sides of the river, and strongly favour 

 the view that the succession in the rocks noted was dependent 

 originally on stratification. 



If the thickness of the schists at Cruger's Point may be taken as 

 that at Stony Point, the submerged Cruger limestone is to be found 

 beneath the bottom mud of the river within a few hundred feet of 

 the south-east shore. 



