GEOLOGY OF LAKE PLEASANT QUADRANGLE 9 



Falls dolomite, Black River limestone (Lowville), Trenton lime- 

 stone, and Canajoharie (Trenton) shale are all represented. 



The whole region of the quadrangle has been literally cut to 

 pieces by numerous normal faults, the fault ridges and blocks form- 

 ing the dominant features of the topography. 



This region, in common with most of the rest of the State, was 

 buried under the great ice sheet of the Glacial (Pleistocene) epoch, 

 so that all the ordinary glacial phenomena may be observed. 

 Glacial deposits are widespread, the more important valleys usually 

 containing heavy glacial lake and morainic deposits. 



The following papers contain statements which bear more or 

 less directly upon the geology of the quadrangle : 



Darton, N. H. Geology of the Mohawk Valley. i8th Annual 

 Rep't N. Y. State Geol. for 1893, p. 608-9. 



Emmons, E. Geology of the Second District, 1842, p. 417. 



Kemp, J. F. Physiography of the Eastern Adirondacks in the 

 Cambrian and Ordovician Periods. Geol. Soc. Am. Bui. 8, 

 p. 408-12. 



Kemp, J. F., Newland, D. H., & Hill, B. F. Preliminary Report 

 on the Geology of Hamilton, Warren, and Washington Counties. 

 1 8th Annual Rep't N. Y. State Geol., p. 134-62. 



Miller, W. J. Early Paleozoic Physiography of the Southern 

 Adirondacks. N. Y. State Mus. Bui. 164, 1912, p. 80-94. 



The Geological History of New York State. N. Y. 



State Mus. Bui. 168, 1913, p. 42-43. 



Ruedemann, R. Additional Note on the Ocean Current in the 

 Utica Epoch. Am. Geol., Feb. 1898, p. 75-81. 



PRECAMBRIC ROCKS 

 Grenville series 



So far as known, these Precambric rocks are to be classed with 

 the oldest formation in the crust of the earth. They represent a 

 thickness of thousands of feet of sedimentary rocks now highly 

 metamorphosed and crystallized so that much of the original sedi- 

 mentary character has been obliterated. The sedimentary character 

 is best shown by the repeated and rapid alternations of bands or 

 layers of distinctly different composition ; the presence of such 

 rocks as crystalline limestone and quartzite ; and the presence of 

 scattering flakes of graphite. These are the usual characteristics 

 of the Grenville throughout the Adirondack region and they are well 

 exhibited within the Lake Pleasant quadrangle. 



As regards areal extent, however, the Grenville of the quadrangle 



