4 [January, 



On the Ancient Alluvium of the Ohio River and its Tributaries. 



By Alfred T. King, M. D., of Greensburgh, Pa. 



The Ohio River, and all its tributaries which I have examined, are bounded 

 by an ancient alluvial deposit, rising from one to two hundred feet above the 

 present beds of those streams, and extending from half a mile to nearly two 

 miles in width. 



In the brief description which I design to give of these deposits I shall com- 

 mence with that extensive and remarkable one at the mouth of the Beaver 

 River. 



This is a beautiful and romantic stream, rising in the northern part of Beaver 

 County, Pennsylvania. It runs nearly south, and empties into the Ohio river 

 about thirty miles below Pittsburgh. At its mouth are two small towns, 

 Rochester on the east and Bridgewater on the west. The town of Beaver, which 

 is the seat of justice of Beaver county, is situated on the hill immediately above 

 and west of Bridgewater, on an alluvial plain, two miles and a half in length, 

 one mile, or nearly so, in width, and one hundred and thirty feet above the bed. 

 of the Ohio, stretching along the northern shore of that river. Although wells 

 have been sunken, in different parts of the town, 128 or 130 feet, which would 

 be about on a level with the bed of the Ohio, still no one has penetrated through 

 this deposite. The strong probability is, therefore, that it extends many feet 

 beneath the present bed of the river. On the opposite side of Beaver river this 

 deposite stretches along the Ohio, about three quarters of a mile. At both ex- 

 tremities it is apparently transferred to the opposite side of the river, in conse- 

 quence of the present curving of the stream, which causes the water to impinge 

 against the base of those lofty hills which everywhere skirt the shores of this 

 picturesque river. Seldom does the Ohio, or any of its numerous and mighty 

 tributaries, flow through the centre of this ancient alluvium, for this deposite is 

 seen every now and then on opposite shores. 



On the eastern side of Beaver river this deposite is 20 or 30 feet higher than it 

 is at the highest point on Beaver plain, w hich would make it there about 150 or 1 60 

 feet, above the bed of the Ohio. At the most eastern extremity the hills are com- 

 posed of fine sand and loam, containing fluviatile and terrestrial shells of the genera 

 A?iodo?ita, Unio, Planorbis, Paludina, Limnea and Helix. Nearly the whole of 

 the residue of this deposit at Rochester, Bridgewater and Beaver, is composed 

 of nodules of argillaceous oxide of iron, and of rounded, polished river pebbles, 

 from the size of gravel to the size' of a man's head and upwards. 



At the town of Rochester, the Pennsylvania and Ohio Railroad Company has 

 made an extensive cut of about eighty feet through this mass of iron nodules 

 and river pebbles. Here it exhibits symptoms of stratification. Commencing 

 at the summit, there is first a thin seam, which composes the surface soil, of 

 sandy loam, then loose pebbles, below which there is a seam of eight or ten 

 feet of conglomerated pebbles cemented together with an oxide of iron. So- 

 firmly bound together are these pebbles, that the workmen, when making the 

 cut, were obliged to blast them, and I am told that they encountered much 

 more difficulty than they ordinarily do in more solid, compact rock. Below this 

 is a seam of ignitable bituminous coal, about one inch and a half in thickness, 

 extending entirely through the cut, and always preserving the same relative 

 position. Below this coal were loose pebbles again, and so on, alternately, from 

 the summit to the base. 



Doubtless this tendency to stratification in alluvial, as well as in marine de- 

 posites, may be accounted for that streams at different periods transport different 

 materials, but the continuous seams, and vast masses of hydrate of alumina, 

 frequently seen in alluvial bluffs, particularly in those of the Mississippi river, 

 and the pure crystals often seen imbedded in solid sedimentary rocks, clearly 

 indicate the existence of chemical affinity between some of the particles of 

 sediment, in connection with mere mechanical deposition. 



Beaver river is a small stream, not larger than the Mohawk, but its scenery 

 is exceedingly beautiful. Its calm and placid bosom reflects vividly like a 



