516 F. G. CLAPP GLACIAL PERIOD IN NEW ENGLAND 



Other exposures. — Several exposures which resemble old till were ob- 

 served in the southern part of Gardiner, the southern part of York, and 

 on Mount Desert island, Maine ; at Newton, New Hampshire ; and near 

 Canton Junction, Haverhill, and under North Eidge at Ipswicli, Massa- 

 chusetts, and elsewhere. In the towns of Paris and Eumford, Maine, a 

 number of road exposures of a hard, compact type of till were seen, which 

 is very dark in color and of a shaly texture, unlike till seen anywhere 

 else in Maine. In some exposures it is possible that the high colors and 

 old appearance may be due to staining by iron; in others this is clearly 

 not the case. Nearly all these tills occur in depressions in the l)ed-rock 

 where they have evidently been protected from erosion. The Norridge- 

 wock and Portland exposures are exceptions to this statement. 



Figure 3. — Section of Gravel Pit at Portland, Maine. 



Snowing evidences of probable old drift. A, horizontally stratified sand, affected by 

 weathering ; B, sandstone, contain a few boulders ; C, hard, unweatheied clay, resting 

 unconformably on B. • 



Correlations. — These old deposits may not all be of identical age, and 

 no data are at hand by which to judge of their exact age. They are prob- 

 ably as old as the Manetto gravels of Long Island* and the Ivansan or pre- 

 Kansan till of the middle West. These tills are distinguished from the 

 next more recent till (Montauk) by the following characteristics: 



1. By the greater abundance of pebbles of the underlying bed-rock than 

 of rock from a distance. 



2. By the greater abundance of pebbles of rock not easily decomposed 

 (that is, slate and quartzite) and the absence of decomposable pebbles. 



3. By their deeper oxidation and brighter colors. 



4. By their occurrence underneath more recent till. 



• M. L. Fuller : Geology of Fishers island. New York. Bull. Geol. Soc. Am., vol. 6, 

 1905, pp. 373-375. 



