single, narrow, gorge-like valley below. The reasons for emphasizing this 

 area as a division point will be clearer when the details of the different 

 series are understood; but it may be worth while to note certain general 

 differences just here between the terraces and valleys above the area near 

 the junction and tlie corresponding phenomena below. The more obvious 

 or the more important differences are : 



1. Different materials ; slopes mainly of outcropping bed reels below, 

 mainly of glacial drift above. 



2. Different number of terrace levels ; four clearly marked below ; 

 seven above. 



3. Different gradient of terraces ; slope being upward in the down- 

 stream direction, or nearly horizontal below the junction area ; level to a 

 gradient about the same as the beds of the streams above the area. 



Summary of Observations on Terraces Above the Gorge. 



The diff"erent terraces along the tlu'ee forks of the Whitew-ater can be 

 referred to seven different series. For the "West Fork these seven series 

 are indicated in Fig. 3 by broken lines numbered from (1) to (7) inclusive. 

 In nearly every case each series is made up of a number of disconnecte<? 

 terrace remnants. The total number of these remnants along the West 

 Fork is 51 ; along Middle Fork, 26 ; along East Fork, 31 ; total, 108. From 

 this total when deduction is made for terraces counted more than once 

 near the junction of the streams, the net total is 103. 



In size these remnants vary greatly. The largest forms the surface on 

 which the principal part of West Richmond is built, and contains about 

 420 acres; its total length is more than li miles, and its width from | to 

 i mile. This terrace is a part of the fourth series and has an elevation 

 above the stream at its south end of 82 feet; at its north end, of 45 feet. 

 At its southern end bed rock is within a few feet of the surface; farther 

 north the covering of drift, mostly assorted, becomes thicker. 



At the other extreme of size are tlie very small patches forming flat- 

 topped points or shoulders, in some cases having areas of only a few square 

 feet. These exceedingly small patches, wliile sometimes of value in the 

 field in correlating remnants of terraces, liave not, however, been included 

 in the count of terrace remnants given above. The smallest area included 

 In the numbers as given contains about one-fifth of an acre ; the average 

 is, however, much larger, being for the 103 areas a little over 20 acres. 



