192 FROZEN WELL. 



on our Map of Surface Geology he has marked six other cases, viz., on the north side 

 both of Great and Little Averill Pond; on the north shore of Island Pond; the east 

 shore of a pond in Maidstone ; the east shore of Memphrernagog at its south end ; and 

 on the east, west and north shores of a pond in the south part of Franklin. Mr. Hall 

 states that the rampart on some of these is 15 feet high. 



These facts we believe are new to geology, with one exception perhaps, on Lake Onega 

 in Russia, and by what agency could these ramparts have been produced ? for we are not 

 inclined to refer them to human agency. But we think the ice of winter could have done 

 the work. If the ponds, or some parts of them, are rather shallow, and the bottom 

 covered by bowlders, the ice of winter would inclose the stones and the gravel of the 

 bottom it may be, and from its well known property of expansion it would force the 

 fragments from the central parts of the lake towards the shore. In one year the progress 

 would be small ; but in each succeeding winter the work would be resumed, until at 

 length the fragments would be driven to the shore ; and as the level of the lake, or at least 

 of the ice, is usually higher in the winter than in the summer, they might be crowded 

 a considerable distance beyond low water mark, and in the course of ages the accumula- 

 tion might be large if the materials at the bottom of the pond were abundant. Formed 

 in this manner, their outside would be as steep as rounded stones could be made to lie 

 upon one another, and no wonder such walls should be regarded as of human production. 

 We doubt not, now that a few cases have been pointed out, that many more will be found 

 around the ponds and lakes of Vermont, as well as of other northern States. 



DEPOSIT OF FROZEN GRAVEL WITH A FROZEN WELL IN BRANDON. 



The presence of a mass of frozen gravel deep beneath the surface in Brandon, was first 

 made known by digging a well through it in the autumn of 1858. The low temperature 

 of the well the next summer called public attention to it. We visited it as soon as con- 

 venient, and up to the present time (October, 1860), some of us have been there repeatedly, 

 and ascertained the facts respecting this well and the deposit, as they have transpired. 



The frozen well is situated not far from a mile southwest of the village of Brandon, and 

 from an eighth to a quarter of a mile east of Otter Creek. The surface is not raised vci'y 

 much above the river, and is undulating, a good deal sandy and gravelly, with one of the 

 varieties of Eolian Limestone showing itself occasionally in bosses and low ridges, break- 

 ing through the gravel, and doubtless underlying the Avhole superficial deposit at no great 

 depth. The gravel, also, rises into occasional knolls and ridges. In short, it is just such 

 a region of sand and gravel as may be seen in many places along the western side of the 

 Grreen Mountains ; and, indeed, all over New England. It is what we call modified drift, 

 and lies above genuine drift, having been the result of aqueous agency subsequent to the 

 drift period. It belongs to the terrace period probably to nearly the oldest terraces, 

 which we have called Moraine Terraces. But greater detail will show the structure of 

 the deposit at and around the well, where the frozen deposit was penetrated. Several 

 wells have now been -dug as deep as the frozen one in its immediate vicinity, but none of 

 them have gone through to the subjacent rocks, so that the character of this rock r.-in lie 

 of little consequence in our inquiries. 



