GEOLOGY OF OGDENSBURG II 



general surface is a clay flat, above which the higher knobs of the 

 moraine project. 



The only considerable drift hill in the whole mapped district is 

 the rather boldly projecting ridge known as Mount Lona, about 2 

 miles south of Heuvelton, midway of the Ogdensburg sheet. Its 

 north front is at the river edge, at the sides it rises rather abruptly 

 from low, flat country, it trends south wxst, parallel with the general 

 direction of ice motion, has a length of about a mile and one-half, 

 and a breadth of one-half of a mile. Its summit has an elevation 

 of 466 feet, the highest point on the map with the exception of one 

 or two of the grani-te knobs near Dekalb Junction, which are a few 

 feet higher. It towers 160 feet above the country on the north 

 and east, and 100 feet above that on the southwest. 



The ridge is entirely composed of bouldery drift, probably 

 morainic. It stands on a sandstone plain, with rock near the 

 surface, and occasionally outcropping around the margins of the 

 knob. A low moraine stretches from it toward the southwest, but 

 a moraine of no particular bulk or prominence. The hill somewhat 

 suggests a drumlin, though somewhat more abrupt, more prominent 

 and more elongated than the usual drumlin. The lack of other 

 hills of the same type in the district tends to throw doubt on such 

 a classification also. We were unable to devote any particular 

 attention to the drift deposits of the region, and simply chronicle 

 this hill as an interesting point for study. Because of its promin- 

 ence it was thought that perhaps shore line features would be 

 shown upon it, but we could detect none, .and apparently the marine 

 waters must have overtopped it somewhat. 



A much smaller and less conspicuous hill of similar type is that 

 at Lost village, 5 miles south of Ogdensburg, on the west side of 

 the Oswegatchie at the point where Black lake outlet empties into 

 it; this is also a purely morainic hill, resting on bedrock, and with 

 no particular connection with a morainic belt. 



Though the general surface of the Ogdensburg quadrangle con- 

 sists of a clay plain, above which low, morainic summits rise, 

 locally considerable sand rests upon the surface. Much of the 

 sand is in the lee of the moraine knobs, in the fashion of sand 

 spits, similar to the many occurrences of the same sort on the 

 Theresa and Alexandria Bay quadrangles. But there is also much 

 sand as knolls mingled with the moraine knobs, which seem to be 

 of the kame type, and the chief moraine is probably a kame 

 moraine, its features masked because of its subaqueous formation. 



