SCIENTIFIC SURVEY. 



295 



there is a huge boulder, as "large as a barn," which lias been 

 split into two pieces. His son, also, has picked up very interest- 

 ing fossiliferous boulders, which must have been derived from some 

 undiscovered belt of rock. In Dr. Jackson's third report, page 2T, 

 there is a notice of a large boulder of magnetic iron ore, weighing 

 1T4 pounds, which was found near the village of Phillips. Last 

 year a similar boulder was found in Salem. Whoever can find the 

 vein from which these boulders were derived, will do good service 

 to the community. Passing on towards Rangely we find the axis 

 of Saddleback mountain to be composed of mica schist, only it has 

 more of a gneissic aspect than the rocks in the valley. At Long 

 Pond a new variety of mica schist succeeds, which has been 

 described in a previous portion of this report. 



The geology of Oxford county is peculiar. From the little we 

 have seen of it the following is our impression of the whole. Orig- 

 inally the whole country was occupied by a schistose formation of 

 essentially uniform character. Being in a favorable situation for 

 the action of metamorphic changes, so much granite has been pro- 

 duced and thrust among the strata, that it is now the prevailing 

 rock. The country is made up of mountains, hills and valleys ; 

 without any level tract except scanty meadows along the banks of 

 rivers. Now nearly all these mountains and hills are composed of 

 gi'anite, while the lower districts are occupied by mica schist, 

 gneiss, silicious slate or quartz rock, and indurated limestones. 

 We have never heard of any other district of the same extent with 

 such a singular arrangement of azoic rocks. Upon a properly con- 

 structed geological map the colors will be seen to conform to the 

 topographical features of the country ; and numerous sections can 

 be made which will conform to the old theory of the structure of 

 mountains, that their central and interior portions are composed of 

 intrusive granite. It is hardly necessary to add that an accurate 

 geological map of the western part of the State will present the 

 true arrangement of the Oxford county rocks, besides correcting 

 any false impressions which may have been already received re- 

 specting them. 



The following changes in the character of the rocks were noticed 

 in travelling between Welokenebacook lake and South Paris. Gran- 

 ite extends for about three miles south of the lake. Then, com- 

 mencing at the summit of a mountain range, succeeds mica schist, 

 often gneissoid. About eight miles from the lake we saw the first 



