354 BOARD OF AGRICULTURE. 



isle, which is to the east and has a dip of 85° north 30° west, a 

 synclinal axis. The cleavage and strata here are at right angles. 

 Several other islands, together with the outcrops along the south- 

 eastern shore, are composed of the same clay slate ; and what is 

 peculiar to this part of the lake, is that the strata are tilted so as 

 to be nearly perpendicular. 



Upon reaching the extremity of the lake in this direction, we 

 proceeded up on the other side, and found an entire change in the 

 character of the rocks. They are an unstratified trap conglome- 

 rate, forming extensive ledges all along the south-west shore. 

 At first it was an unmistakable trap conglomerate — trap boulders 

 and a trap matrix, but further on the cementing material disap- 

 peared, the boulders growing larger and assuming that concre- 

 tionary or nodular character spoken of by you on page 410 of your 

 Preliminary Report as occurring on Heron lake. The largest 

 boulder we measured here was five feet long. From the fact that 

 genuine conglomerate is found in such close proximity and merg- 

 ing into this latter rock, there can be no doubt as to its true con- 

 glomeratic sedimentary character. 



On either side of a valley running in upon this part of the lake 

 is a range of mountains presenting marked differences in appear- 

 ance, — that to the east is lower, and has a rounded, graceful out- 

 line, showing the soft, easily disintegrating clay slate of which it is 

 composed, while those on the west side have a more broken, rugged 

 contour. The upper part of these latter are very precipitous, so 

 much so as frequently to prevent the growth of vegetation, and 

 leave the rocks exposed, which looked very much like trap. This 

 surmise was afterwards confirmed in passing along the portage 

 skirting the base of this range by the great quantity of angular 

 trap boulders we found. The mountains all along the west side of 

 the lake and extending back from it, were, I have no doubt, trap 

 mountains, as they exhibited the same shouldered wedge-shaped 

 sharpness of outline. 



By mistake, we found our way to Ellis brook pond, a small and 

 very shallow sheet of water one mile south of Alleguash lake. 

 The strata are exposed in a great number of places, both around 

 the shore and on islands. The rocks are the same as those of the 

 eastern shore of Alleguash lake, having a general north-west dip. 

 We made but few observations here, of which one on the south 

 shore may stand for all. Here the dip was 15° north-west. In 



