PHYSICAL HISTORY OF NEW HAMPSHIRE. 



535 



formation of a very fine siliceous mud, with dolomite, soapstone, and 

 serpentine. More gold was deposited in this period than in the first. 

 Third, the formation of a small bed of conglomerate composed of quartz 

 pebbles, possibly derived from the rocks of the first and second divisions. 

 Some gold is present in this conglomerate, which seems to be mechani- 

 cally mixed with the pebbles. This bed indicates the existence of a 

 strong current, sufficient to carry along fragments of gold. 



The relations of the Huronian to the Labrador series are interesting. 

 Fig. 6 1 shows a section from Northumberland falls to Pilot mountain. 

 Between Mts. Lyon and Pilot the middle member 

 of the Huronian is disposed in synclinal form, and 

 reappears on the west. The junction between the 

 quartzite and felsite is obscured by drift. Near by 

 an exposure has been discovered where the quart- 

 zite stands vertically, abutting against the felsite. 

 On breaking off large masses of the quartzite, the 

 felsite was seen extending downwards, whence it 

 appears evident that the felsite was the oldest, un- 

 derlying the slate unconformably. It is therefore 

 probable that the felsite of Mt. Pilot unites with 

 the rock of Mt. Lyon underneath the Huronian. 



When the crust of the earth was shrinking, I 

 suppose that the felsite hills were brought nearer 

 together without essentially disturbing their strati- 

 fication. The rock is massive and very tough; 

 while the slaty Huronian rocks between them were 

 pliable and easily doubled up by the lateral shoving 

 force. This conjecture will explain the seeming 

 anomaly of horizontal rocks being older than the 

 adjacent highly inclined strata. 



The Huronian strata are remarkable for dipping 

 at a very high angle, almost constantly. The com- 

 mencement of their inclination was probably in- 

 duced at the close of this period, since these strata are much more 

 highly inclined than those deposited in the following age. 



