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JOSIAH BRIDGE AND B. E. CHARLES 



initial dip, and the entire mass appears to rest against an old east- 

 ward facing slope developed on the Jefferson City dolomite in a 

 post-Beekmantown pre-Onondaga erosion interval (Fig. 3). 



The Jefferson City formation has been 

 found outcropping to within ten feet of the 

 summit of the hill on the east side and to 

 within fifteen or twenty feet of the summit 

 on the west side. Overlying the Jefferson 

 City beds on the west side is a layer of 

 large bowlders containing a typical Burling- 

 ton fauna. This layer is continuous for 

 several hundred feet, and the bowlders are 

 quite large, and it seems altogether prob- 

 able that they are in place, or that they 

 have not been moved far from their original 

 location. On the east side of the hill this 

 layer is not as prominent, but bowlders of 

 Mississippian and Pennsylvanian float are 

 abundant all over the hillside, and some 

 of them rest directly upon the Devonian. 



LITHOLOGIC CHARACTERISTICS 



Lithologically the Devonian rock is a 

 hard, dense quartzite breaking with a 

 sphntery fracture. In color it ranges from 

 white through gray to bluish and almost 

 black. The lighter shades predominate. 

 Thin sections show great numbers of well- 

 rounded quartz nuclei with strong evi- 

 dences of secondary growth. In some 

 sections the grains show as angular inter- 

 locking crystals because of this secondary 

 growth; in other sections, large second- 

 arily enlarged grains are separated from each other by a finely 

 crystalline ground mass of the same material. The rock contains 

 numerous cavities, most of which have been formed by the leaching 

 out of large fossils, and on the surfaces of these cavities are to be 



found many small but perfect crystals of quartz and of Kmonite 



