Hershev.] The River Terraces of the Orleans Basin. 



445 



having been worked down on to it from the high bluff back of 

 it. From mining done at low water, and from a shaft sunk 

 several years ago, it appears that back of the rim whose surface 

 is ten feet above the river, there is a channel nearly or quite 

 as deep as the present river level. In the highest floods the 

 river reaches within fifteen feet of the top of the bar. How- 

 ever, this bar is distinctly older and higher than any modern 

 deposit of the river. 



Between the Pearch Mine and Redneck's house there is a 

 flat several acres in extent whose surface is about forty-five feet 

 above the river at its ordinary stage. No bed-rock is exposed 

 along the bank, but it may occur to twelve or fifteen feet above 

 the river, as a modern gravel bar 300 feet wide and ten feet 

 high intervenes between the bank and the stream. Redneck is 

 mining along the bank, the bottom of his excavation being about 

 fifteen feet above the river. It shows a moderately coarse river 

 gravel of brown color in the lower twenty feet, and a finer 

 gravel in the upper ten feet, with a black soil at the surface. 

 Where the material in the bank is damp it has a dark brown 

 color. The Redneck buildings apparently stand on another 

 small remnant of this terrace. 



West of the village of Orleans this terrace spreads out into 

 a broad plain comprising about 200 acres. It has an average 

 altitude of 526 feet, but the surface is slightly undulating. Bed- 

 rock is exposed along the river, rising mostly to ten or twelve 

 feet above low water, although downstream it gets lower. Over 

 it there is a coarse, bouldery gravel bed fifteen to twenty feet 

 thick. This is overlaid by fifteen feet of dark brown sand. It 

 is the erosion of this sand bed which gives the terrace its gently 

 undulating surface. Near the river the sand has been scoured 

 off the gravel in strips several hundred feet wide, producing an 

 apparent lower terrace, as at Sandy Bar. These lower levels 

 are gravelly on top, thus differing from the regular terraces. 



The Orleans post-office stands on this terrace, at an altitude 

 of 520 feet. Opposite it the river at low water has an altitude 

 of 475 feet, thus yielding forty-five feet as the height of the 

 terrace. 



On the south of the river, west of the Ferris Mine, there is 



