38 PHYSICAL GEOGRAPHY. 



" The specimen brought by Mr. Huntington is a labradorite or norite-rock, which 

 resembles in composition and aspect that of the Labradorian, with this difference, how- 

 ever, that it is much more tender and friable, — and, in this respect, resembles the gran- 

 itic gneiss of the White Mountains, as compared with similar rocks in the Adirondacks." 



I first visited the locality August i8 and 19, 1871, and subsequently on 

 September 20, in company with Prof. J. D. Dana, ll. d., of New Haven, 

 Conn. The conclusions derived from these two visits appeared in a short 

 article by myself in the journal above cited, followed by descriptive 

 analyses of some of the rocks by Mr. E. S. Dana, of New Haven, Conn. 

 The description of the rocks agrees with that which appeared subse- 

 quently in the 1871 report, save in one or two particulars, which I will 

 mention. 



In ascending from " Beckytown," the first rock seen was called gneiss, 

 with nodular orthoclase, with its supposed strata dipping by compass 80° 

 S. 70° W. This rock is evidently the same with the "trachytic granite" 

 of Mt. Osceola and elsewhere. After noticing its distribution in mass 

 throughout so large a portion of the mountains, and its nearly horizontal 

 position between the coarse granite below and the felsites above, the pre- 

 sumption arises that these so-called strata may be bands of mica whose 

 planes do not correspond with those of accumulation, but have been 

 superinduced during the metainorphism of the rock. The jointed planes, 

 dipping about 25° westerly, would be those of stratification, if the rock is 

 stratified. These were pointed out by J. P. Lesley.* 



A few rods up Norway brook appears the first ledge of the ossipyte_ 

 Its junction with the gneiss is concealed by drift. For about a mile 

 similar ledges occur, some exposures being sixty or seventy feet long. 

 Considered as an isolated case, it is difficult to determine the planes of 

 stratification, since two prominent sets of jointed planes exist, either of 

 which might be taken for strata. One set dip about 20° northerly, and 

 are the most numerous; the other dip about 75" W. 10° S. As the lat- 

 ter correspond better in position with the supposed strata of nodular 

 gneiss, it was thought they indicated the proper lines of deposition. The 

 former, however, are what appear at the first glance to be the strata ; and, 

 as by this interpretation the position of the rocks at Waterville will 



Proc. Amer. Acad. Sci., Philadelphia, 1S63, p, 363. 



