LEWISTON-DUEHAM SBKIES. 201 



at the north end, this series Hes in a region covered by marine clay. Its 

 length is about 5 miles. 



A small plain of gravel, cobbles, and rounded bowlders, which appears 

 to have no connections, is found about 2 miles northwest of Freeport Village. 

 It will be more fully described later. 



LEWISTON-DURHAM SERIES. 



This is a discontinuous series of short ridges, domes, and plains, sepa- 

 rated by the usual intervals. It appears to begin as a terrace in the 

 southern part of Greene, a short distance east of the Androscoggin River 

 and about 75 feet above it. The gravel here is but little waterworn, yet 

 plainly has had the finer detritus washed out of it. From this point the 

 series continues along the left bank of the Androscoggin River throug'h 

 Lewiston to the west line of Durham, but for 2 miles in Auburn a nearly 

 parallel series is found also on the right bank. One of the smaller mounds 

 of this series is found in the city of Lewiston, a short distance from the 

 end of the upper wagon bridge between Lewiston and Auburn. It is 

 composed of well-rounded gravel and cobbles. 



The two parallel sei'ies of gravels in Lewiston and Auburn are found 

 at or near the brow of the steep banks on each side of the river channel. 

 These places would be favorable to the foriiTiation of crevasses in the ice, 

 and the appearances indicate that a subglacial river flowed on each side 

 of the valley, and that they united into one stream about a mile east of 

 Lewiston. The domes of this series vary in height from a few feet up to 

 100 feet. They are covered or partly covered by the marine clays as far 

 north as Lewiston, and how much farther is uncertain. The lower clay at 

 Lewiston contains various marine shells; the upper clay is sparingly fossil- 

 iferous. The only fossil I have been able to find in the upper clay is a 

 marine alga, a frond of sea lettuce, found a short distance north, of the 

 Androscoggin River in Lewiston. This was at an elevation of about 220 

 feet. When the sea stood at the contour of 230 feet, it would extend 2 or 

 more miles above Lewiston. 



The condition of western and central Maine during the last of the Ice 

 period proper and during the subsequent time when the ice was melted over 

 the valleys but still lingered in the country lying to the north will, when 

 fully investigated, form the basis for an interesting chapter in geological 



