Kemp — Geology of Essex County. 



591 



The Boreas river passes out of the southwest corner of the town into 

 Minerva, with various minor tributaries heading in hills of moderate 

 elevation. 



Geology. So far as I have explored North Hudson, only the rocks of 

 Series III have been met. I have crossed the northwestern corner, coming 

 down from Marcy to the Upper Ausable lake. All the rock visible was 

 anorthosite. In the northeast and east all the roads on the map have been 

 traversed and the anorthosites, related gneissoid types and gabbros have alone 

 been met, but it is quite possible that the gneisses of Series I may be present 

 in the northeast corner. No. 60, near Underwood, is crushed anorthosite ; No. 

 61 is massive gabbro ; No. 63 is also massive but is very finely crystalline ; No. 

 64, near Root's hotel, is typical crushed anorthosite. All along the higlnvay 

 that comes in at Chafey's from the east, is Series III, an extension of the 

 great area that forms the prominent knob of Harris hill just over the border 

 in Moriah, and Moose Pond mountain in Crown Point. The road that comes 

 in to the main highway, just south of No. 64, from Johnson's pond, traverses 

 anorthosite all the way. At No. 103a, where the highway along the Schroon 

 river crosses the town line, there is an outcrop of dark typical gabbro. 



On the highway that crosses the southern half of the town from Root's 

 hotel to Newcomb, the rocks are anorthosites and gabbros more or less 

 gneissoid. Gneissoid rocks of the same type are met on the town line where 

 the trail in the southwest corner crosses the town line. I have reached that 

 point coming up from the south in Schroon. The valleys in the interior 

 of the town have not been visited, but as anorthosites and their related rocks 

 are found on the north in Keene and to the northwest in Newcomb, it is 

 unlikely that any other series will be met.* 



Series I and II are lacking so far as we yet know. 



Series III covers the town so far as our present knowledge goes. See 

 above under Geology. 



Series IV is lacking, but it is extremely probable that it formerly 

 existed in the Schroon river valley, as a small outlier is still preserved at 

 Schroon Lake post office, f 



Series V. No dikes were observed, but they doubtless exist. 



Series VI. The usual sands and gravels are present all along the 

 Schroon river and at times form level stretches of noticeable extent. They 

 are even abundant enough to be quite seriously drifted by the winds in one 



* They have since been thoroughly traversed, and only Series III has been found. 



t A small area of Potsdam sandstone has been found in subsequent field-work, about a mile north of Chafey's, 



