Massive Cnjstalline Roclcs. 



Ill 



Figure 3 represents (-3V of the natural size) an example from the 

 3. soda-granite, half a mile 4_ 



west of Cruger's, where 

 displaced fragments of a 

 thin layer of mica-schist 

 occur in the granite. Fig. 



4 (iV the natural size) is 

 of an inclusion in the 

 norite of Montrose Point ; 

 the distorted form, the 

 fractures, and the faults 

 appear to be evidence of 

 former free movement in 

 the massive norite. Fig. 



5 represents a surface 



three feet square from a large brecciated pyroxenite 

 adjoining directly the crystalline limestone on the 

 shores of the Hudson at Verplanck Point. The 

 masses in this strange breccia are contorted frag- 

 ments of the limestone, one or two feet long, the thin layers of 

 which have been brought out prominently by surface erosion. 



The examples of what appear to be veins or dykes are also numer- 

 ous. They cut through the chrysolite rock and norite of Stony 

 Point and Montrose Point, and through the crystalline limestone of 

 Verplanck Point. Those at the last-mentioned place, facing the 

 river (north of the foot of Broadway), vary from an inch in width 

 to over fifty feet. Some are simply faulted bands, like Fig. 6. 



Others have more irregular courses, as in Fig. 7, representing 

 eight feet from a vein at Verplanck Point. Fig. 8 shows a crossing 

 of two small veins from the same limestone region. Some, if not all, 

 of such veins must, therefore, be true veins or dykes; and are evidence 

 as to the former fused or j^lastic condition of the material and its 

 injection into fissures. Veins formed in this way are not veins of 



