322 GEOLOGICAL AP NEAACSERP 



as the oiyctognostic characters of these rocks, and the appear- 

 ances of gradation from the granular quartz, induce me to re- 

 gard them as parts of the primary strata. Yet, if they are so, 

 they have been subjected to some peculiar cause of irregulari- 

 ty ; for the stretch of the face of the granular quartz, which 

 forms their western boundary, is about N. 56° E., and that of 

 the strata, which bound them on the eastward, is at least 80" 

 E. of N., while the distance between these different lines of 

 stretch, measured along the middle of the channel, is less than 

 thirty yards. 



46. The strata to the eastward are a few feet in thickness, 

 and consist, partly of hornblende-slate, and partly of granular 

 .limestone, varying to a compact dolomite penetrated with 

 quartz. They appear on both sides of the river. Owing to 

 some disorder in them, and a good deal of inflexion in one 

 place, their position could not be well determined ; but their 

 average stretch was judged to lie between 80° and 90° E. of N., 

 and their dip is southerly about 40°. It must be remarked, 

 that these strata stretch from 17° to 27° more to the eastward 

 than the gneiss and mica-slate lower down, and from 50° to 

 60° more to the eastward than the granular limestone on the 

 southern bank. 



47. Above this, the channel of the river opens into a broad 

 and straight reach for a hundred and forty yards. On either 

 side the bank is high, and exhibits the bare rock along its 

 foot. 



48. Beneath the northern bank, the strata last mentioned 

 are succeeded by the red sienite, which may be seen on that 

 side with few interruptions, through the whole of the reach, and 

 for between forty and fifty yards beyond it. Low rocks of this 

 substance often project into the water. 



49. On the southern bank, nothing worth notice appears for 

 near twenty yards, and then (at 4 in the plan) we meet with 



strata 



