SECOND REPORT OP THE DIRECTOR 1905 



13 



been brought about by a slight upward flexure of the gypsum beds 

 and the consequent erosion of the Bertie waterlime and the Coble- 

 skill limestone, which in the adjacent area^are found above the 

 gypsum. In order to demonstrate that the gypsum here is due to 

 an upward flexure, it will be necessary to show that the direction 

 of the dip of the rocks is such as will bring them down to the lake 

 level to the north of the gypsum outcrop along the lake shore. 



The Bertie waterlime outcrops on Hibiscus point, and farther 

 east .toward the railroad the top of the gypsum is several feet 

 above the lake, while the Bertie waterlime above the gypsum is 

 higher than that directly west on the lake shore. A similar ex- 

 amination of this waterlime as observed in the various gypsum 

 pits at Cayuga Junction shows that the slope of the rock is toward 

 the lake. 



From the point where the waterlimes are exposed north of the 

 gypsum at Cayuga Junction, this series of rocks may be followed 

 up the creek south of the railroad and into the fields on the east 

 side of the highway. The dip of the rocks along this creek measured 

 in a line a little to the north of west shows 12 feet in a distance of 

 275 yards. The highest point where these rocks can last be observed 

 here is less than \ mile from the outcrop of the top of the Bertie , 

 as seen in the ledge exposed to the southeast, showing that the 

 rocks exposed in the creek are the Bertie waterlimes since the dip 

 would not permit the 40 feet of gypsum to be interposed between 

 them. 



At Cross Roads the same series of rocks is exposed in Sawyer 

 creek. From the old plaster mill to above the old mill dam, the 

 dip of the rocks in a distance of 50 rods is at least 10 feet. The 

 highest point at which the rocks can be observed in this creek 

 is within 10 feet of the top of the gypsum bed, so that with this 

 dip the waterlime series would be brought above the gypsum. 

 The Cobleskill limestone which is seen above the Bertie in the 

 railroad cut has a dip toward the northwest as may be made out 

 by comparing the Cobleskill on both sides of the cut. 



In following Sawyer creek northwest toward the lake, the fall 

 of the stream is greater than the dip of the rock, so that in about 

 one mile one comes again to the gypsum beds which are exposed 

 along the bank of the creek and which are undoubtedly below 

 the waterlimes exposed farther up the creek. One and one half 

 miles north and slightly west from the gypsum pit at Cross Roads 

 are the old Thompson gypsum quarries. Here the gypsum is 

 capped by the Bertie waterlime and a small ledge of Cobleskill 

 limestone. One half mile directly west from this place the gypsum 

 is seen at least 30 feet below the gypsum in the quarry. 



The conditions found at the Thompson quarry clearly prove 

 that the gypsum is flanked on all sides by the Bertie waterlime 

 and that undoubtedly the same condition holds true at the quarry 

 at Cross Roads and the quarries at Cayuga Junction. 



