May, 1912.] A Study of Buckeye Lake and Vicinity. 527 



aquatic plants with fixed roots and submerged or floating leaves. 

 Such plants as the pond lilies and lotus with large leaves and 

 rhizomes add rapidly to the vegetal deposit and prepare the soil 

 for sedges and other marsh plants which grow in quite shallow 

 water. Sedges are well adapted to holding and adding to the soil 

 and adding to the mat. Thus a sedge meadow was formed. The 

 sedge mat in turn was succeeded by a sphagnum-cranberry bog. 

 In such a mat the circulation of the water becomes impeded, gases 

 set free in processes of decomposition collect and the mat is buoyed 

 up so that it remains at or near the surface of the water. As the 

 mat increased in thickness the surface finally rose above the water, 

 became better aerated and the soil was prepared for shrubs and 

 finally trees. The older portion of the bog was of course on the 

 landward side. As the changes sketched were taking place in the 

 bog it was constantly spreading out farther into the lake. 



When thru the conversion of the swamp into the reservoir, 

 the water level rose rapidly, all the fixed plants were submerged 

 and killed but the floating mat of the cranberry-sphagnum bog 

 was buoyed up on the surface and escaped extermination. Cut 

 off from the shore by the water it became an island. 



The presence of this bog presents conclusive evidence that the 

 body of water in which it developed dates from the close of the 

 glacial epoch. 



The map of the survey of 18U1 contains a number of smaller 

 swamps to the west and northwest of the "Big Swamp." All of 

 them have been drained and are either wood lots or are under 

 cultivation. They vary in size from mere depressions in cultivated 

 fields and meadows to 400 acres in area. Of these swamps the 

 largest, known as "Bloody Run" or "Pigeon Roost" swamp, is 2 

 miles east of Kirkersville and 3^ mile south of the Ohio Electric 

 railway. It is now almost wholly under cultivation, but 13 years 

 ago it was a bog forest of soft maple, swamp ash and white elm 

 with an undergro\\1:h of willow and poison sumac. A drove well 

 on one of the farms show^s 17 feet of peat, then 3 feet of yellow clay, 

 below this hard pan covering the gravel from which comes the 

 water supply. These smaller swamps all lie at a lower elevation 

 than the 900 foot level and as even the largest has a substratum of 

 glacial clay they must have occupied depressions which were due 

 to the inequalities of deposition. 



III. The location and extent of the Newark river valley 

 from Newark westward to the Franklin county line. 



Frequent reference has been made to the existence of a broad 

 and deep pre-glacial valley extending from Hanover westward to 

 the Scioto Basin. Mr. M. C. Read was, I believe, the first to 

 mention this valley. In the Report of the Geology of Licking 

 county^ Mr. Read writing of this pre-glacial channel says: "A 



9. Read, M. C. Geology of Licking County, O. Geol. Survey 3: .348, 1878. 



