1868.] ^^^ [IhiydLMi. 



above the footof tlie hills, were some singular illustrations of the 

 dynamics of geology. On the south-west side of the stream 

 and inclining eastward or south-eastward the entire series of 

 red and variegated beds are shown in their order of succession 

 1500 to 2000 feet in height. At the foot of this escarpment 

 is a low ridge of the red material, which is so grassed over that 

 the connection cannot be seen with the sienite nucleus. This 

 covers a belt of sienite, about two hundred yards wide and 

 three to five miles long, the jagged masses of rock reaching a 

 height of one thousand feet or more, and standing nearly verti- 

 cal or dipping slightly to the south-east. Between the sienitic 

 beds and the river are the two low ridges of Cretaceous Xo. 2 

 and 3 which seem to have been lifted up with the sienite, but to 

 have fallen back past a vertical position, so that they now incline 

 from the sienite ridge, while on the opposite side the beds have 

 a regular dip from the ridge. This peculiarity seems to be com- 

 mon in various localities, owing to the fact that the metamorphic 

 beds which composed the central portion of all the mountains 

 had suftered upheaval prior to the deposition of the unchanged 

 beds. Therefore in the quiet elevation of the mountain ranges 

 the beds are merely lifted up in the direction of the dip of the 

 older rocks, while they are as it were pushed away from the 

 opposite side, forming what ma}' be called an abrupt or incom- 

 plete anticlinal. 



On the opposite or south side of the river there is a gradual 

 slope of 2000 feet above the bed of the stream, the strata incli- 

 ning 5° until we reach the nucleus of another mountain range ; 

 so that we have here as it were two huge monoclinals. These 

 monoclinals form local anticlinals, inasmuch as, in some places, 

 all the beds incline for a short distance from a common axis. 



On the north side of the river, and east for ten to twenty miles, 

 the flanks of the mountain ranges are covered with the un- 

 changed rocks, which give comparativel}^ gentle grassy slopes, 

 owing to the readiness with which they yield to atmos- 

 pheric agencies. Through these slopes many little streams cut 

 their wa}', forming huge canons, which exhibit along their sides 

 the series of beds in their order of succession. 



From a point near the source, for twenty or thirty miles, the 

 river flows through a synclinal valley, the conspicuous red beds 

 dipping from either side. Along the A-alley of the river are 

 marked deposits of drift, the result of glacial action ; but the 

 most beautiful feature is the well defined terraces, about fifty 

 feet high and smoothed olf like a lawn. These terraces are 



