Trans. N. V. Ac. Sci. 22 Nov. 19, 



Dr. N. L. Brixton reported the abundant occurrence of kyanite 

 crystals in the mica schist at an excavation near Madison Avenue 

 and Fiftieth Street. 



Dr. A. A. JuLiEN referred to a locality of the same mineral near 

 the corner of Ninetieth Street and Eighth Avenue. 



Prof. D. S. Martin stated that it had been found in great abun- 

 dance, as small crystals, throughout the schist at Forty-second 

 Street and Park Avenue — in quantity sufficient to entitle the rock 

 to the name, kyanite schist. 



Dr. Alexis A. Julien then read a paper, illustrated by many 

 specimens, on the subject of 



NOTES ON THE GLACIATION OF THE SHAWANGUNK 

 MOUNTAIN, N. Y. 



The Shawangunk range marks the county lines of Orange County on 

 its east, and Ulster and Sullivan Counties on its west. Its lowest 

 summit occurs between Blooniingburg and Wurtsboro, 1,271 feet 

 above tide water; its highest, about 1,700 feet. The lowest point in 

 the Wallkill valley at its foot is found at the mouth of the Mongaup 

 on the Delaware, 550 feet above the sea ; the highest at Rondout, 773 

 feet ; along this valley the Delaware and Hudson Canal has been exca- 

 vated, with a descent of only 80 feet to the Delaware at Port Jervis. In 

 this region the highest peak found is Walnut Hill, in the town of 

 Liberty, Sullivan County, 2,130 feet above the sea. 



The Shawangunk Mountain not only marks a line of upheaval and 

 fault, branching southwestwardly from the Hudson River axis, but, 

 along the greater portion of its course, it serves as a line of demarca- 

 tion between the Lower Silurian area of the Wallkill valley on the 

 southeast, and the Upper Silurian and Devonian terrane on its north- 

 west side. At its upper extremity, near Rondout and Kingston, its 

 trend is from a few degrees west of north to a few degrees east of 

 south, but it soon assumes a southwestwardly trend, and so passes 

 over the southern boundary of the State. 



The Oneida or Shawangunk grit and conglomerate cap the range 

 for a distance of 43 miles from the New Jersey line to the vicinity of 

 Kingston on the Hudson, generally nearly horizontal on the sum- 

 mit of the mountain, dipping sometimes to the E. S. E. on its eastern 

 flank, but generally westwardly, from 30° to 60°, on the northwest 

 side, in the vicinity of Sam's Point. Its thickness usually varies from 

 60 to 150 feet, and the broken edges of the strata present mural 

 escarpments of 30 to 200 feet in height, both in the gaps and along 



