342 Dewey on Geology of Wiltiamstoton, ^c. 



coarse-grained and white limestone is found, resting on the 

 mica slate at the west of it. 



At the north and west base of Saddle Mountain, (E) and at 

 a less elevation than the quartz, are extensive strata of lime- 

 stone, inclining the same way as the mica slate of the mountain. 

 It is less distinctly granular, and less white than the other, but 

 belongs to the same rock. It forms tolerably good marble. 

 Between the strata are crystals of carbonate of lime, rhomboi- 

 dal, and tending to the lenticular form. Some of these strata 

 appear to be composed of blended crystals of this kind. In 

 one place are strata of several rods in length and breadth, 

 which are inclined to the southwest, and thus lie against the 

 mica slate of the mountain. The inclination is about forty-five 

 degrees. Unless this limestone be connected with that on the 

 east of Saddle Mountain, (and no connexion has yet been tra- 

 ced,) it must be considered as lying on both sides of the mica 

 slate, or alternating with it. 



6. Argillaceous Slate rests on quartz on Stone Hill, and is also 

 found low down in the valley connected with limestone. It 

 constitutes the hill (P) connected with the Taconick range, 

 and also Northwest hill, (Q,) whose base is compact limestone. 

 A few miles north, this slate is distinctly marked, and in about 

 12 miles, forms hills of roof slate in Hosack, New- York. It is 

 annually carried in large quantities to Albany. On the first- 

 mentioned hill, it contains some talc. 



6. Aluminous slate. This is found in argillaceous slate, in 

 Pownal, 6 miles north, at the base of a hill east of the Hoo- 

 sack. It is used to set colours. 



7. Chlorite. In rounded masses, generally with quartz, 

 scattered through the valley in Williamstown, and found at an 

 elevation of some hundred feet on the hills of the Taconick 

 range. Chlorite slate has already been mentioned as occur- 

 ring on the'same range. 



8. Rubble Stone. In rounded masses through the valley. 



9. Compact Limestone. In several places low in the valley. 

 Near the college it is white and deep gray. In the veins of 

 the latter, talc is diffused in all directions. It contains silex, 

 often from 3 to 15 per cent., and sometimes gives fire with 



