GEOLOGY OF THE LONG LAKE QUADRANGLE 493 



valley belt of the quadrangle is a Grenville belt. Because of 

 the greater strength of the quartzite member of the series, it gives 

 rise to considerable hills in each of the belts, but otherwise they 

 are low. It is quite likely, too, that the lowland along the southern 

 margin of the sheet, and that about Round pond, is really Gren- 

 ville territory. The few exposures seen in each area are of uncer- 

 tain gneisses, and do not suffice to definitely determine what the 

 prevailing underlying rock may be. Except for the lowland along 

 the north margin of the sheet, which belongs to the lake belt 

 and is likely due to down faulting, the main lowlands are owing 

 to the presence of Grenville rocks and their weakness. 



The hills tend to the long ridge type with their major axes 

 trending northeast-southwest. Those w T hich suggest faulting have 

 a northeast pitch to their crest, and a steep, clifflike back slope 

 on the southwest, as seen on Mt Morris and on the ridges 

 east of Little Simons pond. Stony Creek mountain shows an ap- 

 proach to the same type. On the other hand the long, irregular 

 ridge of Rock Pond and Grampus Lake mountains does not at 

 all suggest the type, and the Kempshall mass is not even of the 

 ridge type. There is a tendency on the part of the elevations in 

 the gneiss country to be of the hill, rather than of the ridge type, 

 as illustrated by Mt Kempshall and Buck mountain, while this 

 type is practically absent in the anorthosite and syenite country 

 [pi. 7-9]. 



Drainage lines. In so far as there are belts of weak Grenville 

 rocks, the valleys so located are drainage lines, w T hose trend is 

 determined by that of the Grenville belt. Moose creek, Bog stream, 

 lower Cold river, and the Raquette between Cold river and Moose 

 creek, are the principal streams of the quadrangle occupying 

 Grenville valleys. In so far as the remainder of the water courses 

 are concerned, the lines of weakness which they occupy must be 

 structural rather than stratigraphic, hence must be lines of joint- 

 ing and faulting. Hobbs has recently presented strong arguments 

 for the belief that such lines have had predominant influence in 

 the location of the drainage lines of New England and Eastern 

 New York. 1 But it is difficult to apply the argument in a district 

 where joints are found with all possible compass directions, as 

 they are within this quadrangle. Yet, as has been pointed out, 

 there are certain directions of more frequent, and more important 



1 Jour. Geol. 1901. 9: 469-84; Geol. Soc. Am. Bui. 1904. 15:483-506. 



