544 F. G. CLAPP GLACIAL PERIOD IK NEAV ENGLAND 



marine fossils were reported by Packard up to 217 feet above tide. 

 Similar exposures, although imfossiliferous, were foi^nd by the writer on 

 Mount Desert island up to 150 feet above tide, and at less elevations on 

 the islands of Casco and Penobscot bays. Sometimes a broad, little 

 eroded deposit of low-level clay is found near a local deposit of high-level 

 cla}^ as at Eockland, ]\:[ount Desert island, Bucksport, and at several 

 places near Portland. Such instances point to the conclusion that the 

 high level claA^s were deposited thousands of years before the deposition 

 of the low-level clays of the coast. 



An interesting locality is in the western part of Augusta, where clay is 

 found up to 320 feet on a hill standing out from the sides of the valley. 

 Other deposits of clay in the vicinity do not rise above 220 to 250 feet 

 above the sea. It is believed this deposit owes its higher elevation to the 

 shoving action of ice. 



7. Occurrence of overlying buried soils. — In 1872 Dawson described an 

 occurrence of peat underlying till in Cape Breton,* and this was referred 

 to by Hitchcock in 1878 and ISSS.f 



No similar exposures have been observed in New England, and it seems 

 probable that most soils were removed by the severe glaciations to which 

 the region was subjected. At Salisbury Beach a "quagmire" is reported 

 beneath clay 50 feet below the surface in well records, but its exact 

 nature is not known. At Portland a series of w^ll records and samples 

 has been seen where the submarine clay is overlain directly by a bed of 

 peaty matter rising to about 30 feet below low-water mark. This bed is 

 described on page 534. As the peat fills the channels in the clay, svliich 

 has been eroded to a depth of 55 feet since the deposition of the latter, 

 there seems good evidence of an extended elevation and subsidence of the 

 land preceding the present epoch. 



WISCONSIN TILL 



General description .—The great mass of the till in New England is 

 the Montauk boulder-clay, described on pages 524-526. Over most of the 

 region there is another type of till, overlying the Montauk and consisting, 

 as a rule, of a heterogeneous deposit of gravel, boulders, and sometimes a 

 little clay. The common appearance of these deposits is illustrated in 

 plate 57, figure 1, where a bed of stratified sand can l)e seen underlying 

 the till. As a rule, this type of till contains much less clay than does 

 the Montaiak type. It is known to form the surface nearly everywhere 



* Canadian Naturalist, second series, vol. vi, p. 178. 



t Supplement to the second edition of Acadian Geology, pp. 27-28. Report of the sub- 

 committee on the Quaternary and Recent. American Geologist, vol. ii, pp. 300-306. 



