GEOLOGY OF THE REMSEN QUADRANGLE 45 



and Black creeks was most likely pushed out over the clay as a 

 delta deposit by the creeks named. The heavy sands around 

 Trenton Falls are thought to be of later origin as delta deposits 

 from West Canada creek when the ice had retreated farther south. 



Erratics 



The whole region covered by the map is strewn with thousands 

 of glacial boulders or erratics. These erratics are mostly repre- 

 sentatives of the Precambric formations, even over the Paleozoic 

 area. They vary in size from those which are very small to 

 others which are lo or 12 feet across and weigh from 50 to nearly 

 100 tons apiece. The accompanying photograph [pi. 11] shows a 

 large syenite erratic resting on the Trenton limestone in the bed of 

 Black creek below Grant. Glacial boulders of considerable size 

 are often associated with the kame-moraine deposits as for example 

 north of Hinckley. Over the typical sand flat areas they are 

 generally absent and this is probably due to the deposition of 

 these sands after the retreat of the ice thus causing them to be 

 buried and lost to view except along the stream channels where they 

 have been again exposed by subsequent erosion of the sands. The 

 erratics over the Precambric area cause trouble in mapping because 

 it is often difficult to distinguish between them and true outcrops. 

 In the fields around Remsen and Alder Creek station hundreds of 

 large erratics may be seen. 



The distribution of these glacial boulders whose source was in 

 the Adirondacks, over the southwestern portion of the district as 

 for instance over Starr hill and to the west as well as for many 

 miles south of this region indicate that at the hight of glaciation 

 the predominating ice current was southerly rather than south- 

 easterly. 



Drainage 



For the most part the larger streams such as Black river, West 

 Canada and Black creeks, now occupy the same channels that they 

 did during preglacial times. The most noticeable exception is the 

 course of West Canada creek below Prospect. Between Prospect 

 and Trenton Falls, West Canada creek certainly passes through a 

 postglacial channel as shown by the series of waterfalls and the 

 steep sided gorge. The writer has every reason to agree with 

 Brigham^ who has discussed the matter and who makes the follow- 

 ing tentative statement. " It is held as possible that before glacial 



' Geol. Soc Am. Bui. 1898, 9:191. 



