REPORT OF THE DIRECTOR AND STATE GEOLOGIST r9T 



matter of the utmost difficulty. It could be accomplished only 

 on an accurate map of large scale. 



One farther point of importance requires statement. Both 

 gneisses, the coarse and the fine, contain characteristic inclusions 

 of the schist, and so the older as well as the younger, as would be 

 thought from its appearance, is igneous, and both are younger 

 than the limestone formation. 



It happens that one of the widely scattered occurrences of 

 hyperite is located here, numerous dikes cutting both gneisses 

 so that the locality has the interest, rather unusual for this 

 region, of showing within a radius of a few rods rocks of four 

 different ages, clearly defined, while a fifth age is shown in the 

 Potsdam, hardly half a mile distant. 



A similar complexity in the gneiss is indicated about one and 

 one half miles north of Redwood on the road to Alexandria Bay, 

 but the phenomena are not clearly shown, and admit of a different 

 interpretation. 



One half mile north of Grasse lake, in the midst of the great sedi- 

 mentary bel+ described above, there is a bold ridge of very coarse, 

 porphyritic red gneiss. It is of a decided red color, with feld- 

 spars an inch or more in length, and is well foliated, resembling 

 closely the coarse porphyritic and augen gneisses so common 

 farther south. Frequent bands and masses in the rock are quite 

 different, being decidedly fine grained. But after a careful ex- 

 amination the writer was unable to decide positively whether 

 there is a difference of age similar to that described above, or 

 the fine gneiss is simply a phase of the coarse. The former is 

 probably the case, but the question is an open one. 



The coarse gneiss is clearly igneous, containing many inclusions 

 of the schist. One of these merits particular mention. A knob- 

 like exposure a few yards in extent shows on one of its rounded 

 sides a sharp contact between the gneiss and the schist. On the 

 opposite side, the gneiss appears in little strings and lumps, 

 somewhat puckered, scattered through the schist in lines parallel 

 to its foliation. The result is the production of a sort of in- 

 jection gneiss of very peculiar aspect, whose origin would be a 



