GEOLOGY OP HAMILTON, WARREN AND WASHINGTON COUNTIES 161 



lake and extends for a considerable and as jet unknown distance 

 to the westward. The principal rock present is a coarsely crys- 

 talline aggregate of labradorite with very little of the dark sili- 

 cates present. There is evidence of crushing, but there has been 

 slight if any development of gneissoid foliation. Specimens were 

 collected near the outlet of Thirteenth lake which show sharp 

 eruptive contacts against the gneiss. Gabbros of basic character 

 likewise appear along the northern side of this area. 



The second area lies to the south of the first and is near the 

 road leading from Bakers Mills to Wellstown. The anorthosite 

 is rather strongly gneissoid and has been more sheared than in 

 the northern locality. Mr Newland observed however a good 

 eruptive contact against the gneiss. 



The' exposures of the anorthosites are the most southerly of 

 those yet discovered in the eastern mountains, and probably mark 

 the limits of the formation in this direction. In statements of 

 this character, mention should however also be made of the 

 augite syenite gneisses, which may belong with the anorthosites 

 in their geologic relations and which were referred to under 

 series 1. 



Series 4. Along the brook that heads to the westward from 

 North River and about 2 miles from the village numbers of large 

 boulders of Potsdam sandstone are found, giving every reason to 

 think that they are not far from their parent ledges. There is 

 little doubt that there is an outlying area of the Potsdam at this 

 point, and the discovery adds another to the remnants of this 

 formation which have already been met, so far removed from the 

 larger southern exposures. 



Series 5. No trap dikes have been observed. 



Series 6. The glacial deposits are widespread and important 

 and should be a special object of study. Morainal material is 

 widely distributed. Glacial scratches have been observed in only 

 one instance, which was about 8 miles east of Bakers Mills. They 

 bore n 32 e magnetic, or about n 20 e true. 



Along the Hudson there is one remarkable terrace about 40 feet 

 above the stream, and opposite the tributary streams are deltas 

 in very striking development, but our observations are not yet 

 sufficientlv detailed to correlate them. 



