ROCKS AT CAMDEN. 99 



stratification is extremely obscure; and were it not for interlaminated slate or other beds, 

 it*would be impossible to determine the direction of dip. It. is difficult to discover the cause 

 of such a condition, which is one that is quite common to limestones of this period. Even 

 in the Massachusetts beds, the stratification is not always distinct. 



There is nothing peculiar to the main bed of quartz. It is interlaminated with a siliceous 

 slate; and like all other beds, this is extremely barren of minerals. The dip is north, or 

 conformable to that of the upper rocks. 



The most interesting mass of this rock is west of Camden village, where it forms 

 Megunticook mountain, an eminence from six to seven hundred feet high. This mass 

 I supposed to be the lowest, and it can not be less than five hundred feet thick. Dip 

 southeast, at an angle of fifteen or twenty degrees. The whole mountain seems but a 

 brecciated or conglomerated mass of pebbles, cemented together by a fine siliceous paste. 

 The layers are jointed : one set runs N. 75° W., and another N. 10° E. 



The pebbles are usually partially rounded, although they appear as if they were all 

 angular. Actual inspection, however, shows that while some are partially worn, others 

 are ?harp and angular. From an examination of these pebbles, they seem to have been 

 derived from the quartz of the mica slate and granite. I was unable to discover limestone 

 pebbles in any of the strata. Abundance of grey mica, in fine scales, gives a glimmering 

 aspect to some portions of the rock. 



Megtinticook mountain rises rather abruptly from a rolling country, and appears insulated 

 from other rocks of the Taconic system. A few rods from its steep sides, a mica slate ap- 

 pears, the surface of which is grooved by diluvial action. I could obtain no evidence that 

 the quartz is embraced in this depressed mass of mica slate ; the whole appearance led me 

 to infer that it rested upon the slate. The ground upon which my opinion in this matter 

 is founded, is the difference in the strike and dip of the two rocks : thus the quartz, as has 

 been stated, dips at a very moderate angle to the southeast ; the mica slate, on the con- 

 trary, is nearly vertical, with a strike N. 60° -70? W.* The two rocks therefore have no 

 coincidence, as they ought to have if the quartz was enclosed in the slate. This result, 

 too, is agreeable to what is elsewhere observed, particularly along the western face of the 

 Green mountain range at Arlington, Vermont. It is true that Prof. Hitchcock considers 

 the quartz as embraced in mica slate in Berkshire. Not to maintain an opinion contrary 

 to high authority in this case, I will only remark that I do not think that it is ever em- 

 braced in the primary schists, or those of the Gneiss system. This mica slate also bears 

 the same characters, and has the same trend and dip as the other masses associated with 

 the gneiss and granite passing between Searsmont and Belfast. What appears to be the 

 fact, therefore, is that we have a primary base underlying the whole region, and forming 

 occasionally wide belts ; and in these belts the true Gneiss or Schist system is comprised, 



•That there is no mistake in determining the dip of the quartz, is shown by the position of the pebbles, which lie 

 with their major axis parallel to the planes of bedding, as is always the case upon a pebbly beach. 



13* 



