CARROLL MORAINE FIELD 279 



north of this plain, a mile long and three-quarters of a mile wide; (c) a 

 pair of kame terraces which appear on opposite sides of Alder Brook, 

 south of the Carroll plain, and connect it with (d) a more irregular, 

 deeply pitted kame plain just north and west of the Twin Mountain 

 House; (e) a prominent esker with associated kames and branch ridges, 

 which runs north and south at the Twin Mountain House, in a course 

 nearly perpendicular to the Ammonoosuc Valley; and (/) 2 miles east 

 of here, near the mouth of the Zealand Biver, another strongly developed 

 esker, which runs east and west beside the Ammonoosuc. It seems not 

 unlikely that this is genetically related to the Twin Mountain esker, 

 although there is no evidence that the two were ever actually continuous. 

 Other esker fragments farther up the Ammonoosuc Valley, near Pabyans, 

 have been, known, and, like these, were described in detail by TJpham. 



TWO OPPOSED VIEWS OF THE ORIGIN OF THE OUT WASH DEPOSITS 



In his paper of 1904 Doctor Upham referred to the deposits near the 

 Twin Mountain House as a 



"very interesting esker series, partly complex and partly a single conspicuous 

 ridge." . . . "This series of eskers, traced . . . about six miles, near the 

 west base of the Mount Washington Range and north and west of the principal 

 and central area of the White Mountains, was certainly formed by a glacial 

 river, inclosed on each side by walls of the departing ice-sheet, and flowing 

 away from that area, that is, from southeast to northwest and west, in the 

 same direction as the present Ammonoosuc River. It demonstrates, like the 

 Bethlehem moraine, that a remnant of the general ice-sheet was rapidly and 

 continuously melting back from the northwest to southeast, lingering latest on 

 the flanks of the Mount Washington and Mount Willey Ranges." " 



TJpham contributed no evidence to show that this esker was formed by 

 a glacial river flowing westward and northward rather than southeast- 

 ward and southward, but repeated certain statements of Hitchcock con- 

 cerning evidences of transportation of erratics down the Ammonoosuc 

 Valley between Fabyans and the Twin Mountain House, the weakness of 

 which will presently be shown. 



A study of the deposits around Carroll have led me to take a different 

 view of the conditions under which they originated, namely, that they 

 mark the discharge of glacial drainage southward through the Beech Hill- 

 Cherry Mountain pass into the ponded waters of the Ammonoosuc Valley 

 during the retirement of the Canadian ice-sheet from these foothills of 

 the White Mountains. The evidence which seems to favor this interpre- 

 tation rather than that employed by TJpham is as follows: 



"Op. cit„ pp. 12-13. 



XXI — Bull. Geol. Soc, Am,, Vol. 27, 1915 



