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ANNALS NEW YORK ACADEMY OF SCIENCES 



feet, the lower, which outcrops on the southern slope of the mountain, 

 is in this region covered with glacial drift. The strata as a whole dip 

 gently west-northwest. 



Glaciation" 



Two glacier streams have swept over this region: 3 the Continental 

 Glacier, and later the more shallow Hudson Valley Glacier. The geo- 

 logic structure of the region makes it somewhat difficult to trace satis- 



Fig. 3. — Map of Overlook region, showing direction of glacial stria (indicated by arrows) 



Contour interval 200 feet 



f actorily the course of the glaciers ; for the sandstones and soft shales of 

 which the mountain is composed have retained glacial markings only in 

 exceptional localities; while a considerable portion of the surface is, of 

 course, covered with glacial drift. 



The map (Fig. 3) shows the direction of the striations left by the 

 Hudson Valley glacier in the Overlook region. It affords an interesting 



3 A. A. Julien : "The Excavation of the bed of the Kaaterskill." Trans. N. Y. Acad. 

 Sci., Vol. 1, p. 24-27. 1881. 



