24 Geology, ^c. of the Connecticut. 



terfield, (N. H.) Putney, Sec. 9. Not very fissile — break- 

 ing into thick blocks. Mica, abundant but poorly charac- 

 terised — having somewhat the aspect of argillite — surface 

 slightly irregular, appears as if grooved — Abundant in Cum- 

 mington, Chesterfield, (Mass.) Vernon, Bolton, &c. 10. 

 Quartz granular, abundant and white — resembling gneiss 

 or granite — scarcely stratified at all — Locality, Buckland, 

 Granville, &:c. 11. Mica in distinct and abundant plates — 

 layers very little tortuous or uneven. This usually lies next 

 to granite. 12. Passing into gneiss — often rendered por- 

 phyritic by crystals of feldspar. Locality, Litchfield county. 



The quartz that occurs in this mica slate, especially in 

 the wavy and tortuous varieties, is commonly the white 

 limpid: frequently it is the fetid, and sometimes a rich vari- 

 ety of a delicate red color. The coloring matter, however, 

 is apparently iron, and therefore it is not the rose-red quartz. 

 This variety of quartz occurs on the west side of the Con^ 

 necticut. 



It has already been remarked, under granite, that nu- 

 merous beds of this rock are contained in mica slate. In- 

 deed, our mica slate more frequently rests immediately up- 

 on granite, without the intervention of any other rock, than 

 does gneiss. It also alternates with gneiss, hornblende 

 slate, argillite and chlorite slate. Small particles of it, in- 

 deed, occur in very many places throughout the whole ex- 

 tent of the primitive along the Connecticut. 



It is a common remark in geological books, that hills 

 composed of mica slate are usually less steep and more 

 rounded than those of granite. But the reverse is the fact 

 in most cases along this river. The granite hills are gener-- 

 ally low and rounded, while some of the most Tarpeian 

 precipices to be found in this region are composed of mica 

 slate. Take for examples West River Mountain, and the 

 high hills of Heath, Hawley, Chesterfield, &c. 



Mica slate is not wanting in a variety of minerals in this 

 section of the country— such, for instance, as staurotide and 

 garnets in immense quantities in Goshen, Chesterfield, 

 Mass. and from Bolton, Conn, one huudred miles north, to 

 Chesterfield, New-Hampshire. Also the fine Chesterfield 

 gfippare. Also the red oxid of titanium, found almost ev- 

 ery where between Conway and Brattleborough, a distance 

 of thirty miles — and the Leyden tremolite — the Putney 



