30 Geology, 4^c. of the Connecticut' 



Hatfield, is a manufactory of common earthen ware, and 

 here a small stream, running east, has cut across the great- 

 er part of the sienite range, and laid the rock bare nearly 

 the whole distance, which does not much exceed half a 

 mile. Let a person follow up the south side of this stream, 

 and in some of the ledges he will perceive a distinct strati- 

 fication of the sienite, though of little extent; one part of 

 the same ledge being often stratified and the other amor- 

 phous. In this place he will see, also, numerous intersec- 

 tions of granitic and other veins by which a part of the rock 

 has been displaced. In one of the ledges a httle distance 

 from this stream, on the south side of a pond, may be se«n 

 the prototype of Fig. 6. 



Another interesting fact may be noticed in the sienitic 

 granite along this stream, especially on the northern side, 

 near the earthen ware manufactory. The rock here contains 

 numerous imbedded massifs of other primitive rocks, as gneiss, 

 mica slate.quariz, hornblende, and a finer kind of siemte. And 

 what is peculiar,is that these imbedded fragments are almost 

 uniformly rounded — as much so as those contained in the 

 conglomerated roi;^ks along the Connecticut; and they are 

 often so numerous that the rock appears like a real second- 

 ary conglomerate. The masses are very firmly fixed in the 

 base, and often there appears a mutual impregnation and 

 sometimes the veins of granite cut through the imbedded 

 fragments, as in Fig. 6. 



Thus we have a real conglom.erated sienite, and I had al- 

 most said a conglomerated granite : for much of the rock 

 containing these fragments is destitute of hornblende, while 

 all the ingredients of granite are present. And the instan- 

 ces in which this conglomerated rock occurs,are not confin- 

 ed to the particular locality above named — but it is to be 

 found in many other parts of the range. I have seen bowl- 

 ders of it in Surry, Alstead and Walpole in New-Hamp- 

 shire, but I did not there see the rock in place. 



Tiie Northampton sienitic range lies at a very low level. 

 A considerable part of it is hidden by a deposit of sand 

 through which it sometimes projects. The sienite in Bel- 

 chertown is also rather low. All the remarks above made, 

 in relation to the Northampton range, except that in regard 

 to its conglomerated character, will apply to this. The best 

 route which I have found for viewing this sienite, after cross- 



