14 XEW YORK STATE MUSEUM 



ous material which is injected into the uppermost part of the sec- 

 tion, leaving as a maximum value for the clastic deposits in this 

 area somewhat over 3000 feet. 



Section B. In continuing the measurement, the composite section 

 begins again at the upper boundary of the amphibolite belt where it 

 crosses the Canton-Russell road, and follows a zigzag and inter- 

 rupted course northwestward to the edge of the map. The first 75 to 

 icx) feet are covered: the exposed section begins vrith the lowest 

 stratum in the shallow syncline which crops out in a low bluff about 

 75 yards west of the road. The measurement is made in the direc- 

 tion of the pitch of the fold, that is, a little north .of west, as in 

 this manner a maximum value is obtained but at the same time the 

 danger of including a measurement of duplicated strata is avoided. 

 The strata here, as noted above, have a spoonlike structure, and it 

 is unlikely that there is repetition of any of the beds. The section 

 terminates at the summit of a small synclinal knoll of quartz schist 

 about a half mile east of a right-angled turn in the Grass river, 

 near a wagon road, which is dotted on the map. The thickness 

 exposed, allowing a maximum average dip of 5 degrees, is about 600 

 feet. 



Section C. From this point northwestward to the broad band of 

 granite gneiss which passes through Canton village, the structure in 

 the limestone valley of the Grass river is indeterminable, and it is 

 accordingly impossible to assign a definite value to the thickness of 

 the formation. Assuming the dip to be uniform, however, and of 

 the average value of dips in this part of the quadrangle, that is, 30 

 degrees, and assuming an anticlinal summit to be present close to 

 the northwest base of the synclinal knoll mentioned, in order arbi- 

 trarily to bring the limestone stratum down under the granite gneiss 

 again, a maximum thickness of 2500 feet is obtained for the valley 

 limestone in this section. 



Section D. The next place where a nearly measurable succession 

 of strata is shown is in the vicinity north of Eddy. Here an extremely 

 intermittent section can be followed from its base, which overlies 

 the border of the prominent oval boss of granite west of Canton vil- 

 lage, to its summit which passes under a sill-like body of gneiss west 

 of Eddv. It is unlikely that this group of beds has been repeated in 

 either of the sections already described. It is barely possible that 

 these rocks are connected with the Grass valley limestone by an iso- 

 clinal flexure which passes over the intervening granite gneiss. As, 

 however, this structural relationship is in the highest degree un- 

 certain, and the limestones, besides being more impure, are associated 



