GEOLOGY OP HAMILTON^ WARREN AND WASHINGTON COUNTIES 143 



amount of green hornblende. This is syenitic in its nature, and 

 is like the Loon lake rocks of Franklin county and the rocks of 

 southern Benson. No. 176 is, however, greatly crushed and granu- 

 lated. Along the Sacandaga valley in the southern part of the 

 town an augen-gneiss with biotite is quite extensively developed. 



The general strike of the gneiss is n 35 w when referred to the 

 true north, and the dip is about 45 n e. 



Series 6. In the valley of the Sacandaga the drift is largely 

 water-sorted and lies in terraces up to 40 or 50 feet above the 

 stream. Unsorted drift is also abundant throughout the town, 

 and its boulders embrace gneiss, gabbro and anorthosite. 



Wells 



Topography. Wells is a large, irregularly boot-shaped town- 

 ship, 20 miles long from north to south, and 15 miles wide ! on 

 the south. The width on the north in the leg of the boot, is about 

 6 miles. The east branch of the Sacandaga runs southwest 

 across the southeastern corner, while the west branch flows east- 

 erly across the southern part. The surface of the township is 

 formed by a succession of extremely rugged hills, which are 

 closely set together. The average altitude is moderate but it 

 gradually increases to the north. Both the east and west 

 branches of the Sacandaga are swift streams, till they unite, 

 and then the descent is more gradual and the current less swift. 

 A number of ponds occur throughout the town, but none are 

 specially large. The valleys are as a rule narrow and are inclosed 

 between steep walls. Except the west branch of the Sacandaga, 

 practically all the streams flow southwest, following the general 

 trend of the valleys. 



Geology. Special interest attaches to the geology of Wells on 

 account of the outlier of Cambrian and Lower Silurian strata that 

 is found near the village of Wells, and which will be fully dis- 

 cussed later. In addition, the other five series of formations, 

 under which the rocks have been customarily grouped in our 

 descriptions, are present, except no. 5, which embraces the trap 

 dikes. The latter may be present, as our explorations have been 



