PLEISTOCENE GEOLOGY OF MOOHRS QUADRANGLE 



21 



A full and satisfactory account of this series of spillways can 

 hardly be presented till the region on the west of the Mooers quad- 

 rangle has been mapped. The outlines of these bare areas shown 

 on the sketch map [pi. 5] are mere approximations obtained from 

 a single traverse of the area between the north branch of the Big 

 Chazy and " the Gulf." 



Blackman's rock. Half a mile southwest from Cannon Corners 

 there begins a bared strip of the Potsdam sandstone which 

 stretches southward nearly to the north branch of the Big 

 (Jhazy river. Only the northeasterninost extension of this spill- 

 way appears on the Mooers quadrangle. This spillway stands 

 at an elevation of about 800 feet. 



Stafford's rock. This stripped area lies wholly west of the 

 Mooers quadrangle and extends from near the north bank of the 

 English river toward " the Gulf " on the south side of Covey 

 hill. It is reached by taking the first left-hand road north of 

 Cannon Corners, which may be followed out northward to " the 

 Gulf." The area appears to be separated from the tiat rock at "the 

 Gulf " on the international boundary by a torrent-washed or at 

 least a bouldery moraine. 



Armstrong's bush flat rock. The settlement in the wooded dis- 

 trict of the northwestern corner of the Mooers quadrangle is 

 known as Armstrong's bush. In the extreme northwest corner 

 of the quadrangle and extending across the boundary line into 

 Canada is a small stripped area lying between 750 feet and 770 feet 

 elevation and at the top of a low hill. Its relation to the other 

 spillways is not perfectly clear. 



From the distribution of the frontal moraines and these spill- 

 ways, it would appear that for some time before the ice sheet 

 melted away from the north slope of Covey hill, its edge as an 

 unbroken wall extended along the northeastern face of the Adi- 

 rondack* between the 680 foot and 000 foot contour lines from 

 Covey hill southeastward to the Little Chazy river in the vicinity 

 of West Chazy. At this last named locality, at least in the later 

 stages of the torrential action along its border, the ice front 

 turned eastward across the valley of Lake Champlain but with 

 out leaving, so far as is at present known, any definite frontal 

 deposits. In front of the ice over the southern part of the 



