FOSSILIFEROUS MARINE CLAYS 539 



Along the Washington County railroad between Cherryfield and Calais, 

 Maine, a number of good railroad cuts show till resting on clay. 



In a road section at Ottar cliff, Mount Desert island, are 4 to 6 feet of a 

 moraine-like deposit of imassorted gravels containing boulders up to 2% 

 feet in diameter, underlain by hard tough clay containing no pebbles. 

 This clay is somewhat yellowed through surface oxidation. 



At Kittery, York, and other places in Maine, and at Kevere, Danvers, 

 and Newburyport, Massachusetts, large boulders have been seen to rest on 

 clay. At York an exposure of till resting on clay was seen. 



4. Folding and erosion due to action of overriding ice. — In many places 

 in this part of ISTew England clays, sands, and gravels have been seen 

 which must have been originally horizontal, but which are now highly 

 folded. The principal examples are as follows : 



A section is given by Marbut and Woodworth * showing contorted clays 

 on the west side of Fresh pond, in Cambridge, Massachusetts. Folds and 

 eroded upper surfaces of the clays, which are attributed by those writers 

 to overthrusting by ice, are also exposed in the clay pits at Cambridge. 



Two miles north of Haverhill, Massachusetts, on the east side of Little 

 river, a brick clay similar to that in the neighboring valley bottom is 

 folded up over gravel deposits 20 feet or more in height. 



At Augusta, Maine, a gravel ]Dit several hundred feet long shows 35 

 feet of gravel overlain by 8 feet of stratified sand, and above that lie 20 

 feet of clay. As shown in plate 58, figure 2, the clay in the center of 

 the pit is nearly horizontal. At the northern end of the section, how- 

 ever, it rises in an overturned fold and is truncated by the surface of the 

 hill. Over a distance of 100 feet at the surface the clay is missing, but 

 about the center of the exposure it comes in again and descends with a 

 dip of 15 to 45 degrees to the base of the section at its south end. The 

 supposed former extent of the clay is shown by the dotted line. 



About 200 feet west of this main gravel pit is a smaller excavation in 

 which the same beds are seen._ They differ from those in the first section 

 in the respect that the clay in the second section contains many sandy 

 layers, and is probably a somewhat lower part of the clay formation. The 

 gravel imderlying the sandy clay here is inclined 30 to 45 degrees from 

 the horizontal. The beds are truncated at the top and are overlain by a 

 very clayey and stony till which ranges in thickness from 2 to 6 feet 

 (^ plate 58, figure 1). In both these sections the strata of sand and cla;» 

 are inclined to-ward the south, but the fold is high and overturned toward 

 the north, indicating that the shoving which produced the folding took 

 place from the latter direction. It seems a fair supposition that this 



* Seventeenth Ann, Rept. U. S. Geological Survey, part 1, p. 990. 



