GYPSUM DEPOSITS OF NEW YORK 29 



seem to be most persistent where overlain by the escarpment of 

 Bertie waterlime, Cobleskill, ]\Ianliiis and Onondaga limestones and 

 for this reason are found mainly in the low hills capped by these 

 limestones and along the stream valleys cutting through the escarp- 

 ment. 



The beds of massive gray gypsum occur beneath small hills be- 

 tween Fayetteville and James ville. The first area is a series of 

 wooded hills ranging in hight from 40 to 100 feet. These lie 2 

 miles southwest of Fayetteville or i mile south or southeast of 

 Lyndon, a station on the trolley line. They are capped by Helder- 

 berg limestone and the gypsum beds outcrop on the sides of the 

 hills, forming a* belt around each hill. The capping of resistant 

 limestone seems to have serv^ed as a protection against the removal 

 of the gypsum by percolating waters. 



Clifford Miller quarry. This quarry is situated i mile directly 

 south of Lyndon, to the east of the road. It has been worked from 

 early times. It is also known as the Heard or Severance quarry. 

 The gypsum bed is about 60 feet thick and consists of a number of 

 alternating layers, varying in purity, color and grain, the individual 

 layers having local names such as the '' cap rock," the " 9-foot," the 

 " ii-loot," etc. They range in color from very light drab in the 

 cap rock to dark or almost black, and at times have a brownish 

 color from the presence of iron. Despite its varied appearance the 

 rock runs rather uniform in gypsum, and no attempt is made to 

 sort the material in the quarry operations. 



The gypsum here is overlain by 2 feet of marlite or weathered 

 shale, followed by 5 feet of thinly bedded blue limestones (Bertie) 

 then 15 or 20 feet of massive porous Cobleskill limestone full of 

 cavities, with a varying thickness of glacial drift and soil as capping 

 to the whole. The heavy mass of overburden becomes more trou- 

 blesome as the quarry is carried farther into the hill and the strip- 

 ping problem becomes a difficult one. The overlying marlite is 

 usually blasted out until, by caving, the whole overburden falls into 

 the quarry excavation and work is resumed on the new face of 

 gypsum. Both hand and machine drills are employed. Black pow- 

 der is used in blasting. The broken gvpsum is loaded by hand into 

 large 20-ton side dump wagons which are drawn from the quarry 

 by a traction-engine a distance of over 2 miles to the canal. The 

 grade is mostly downhill and the road is in good condition. The 

 installation of traction haulage is a new feature in the district and 

 seems to be giving satisfaction. At the canal dock, the rock is 

 dumped down a small embankment, and from there loaded by six 



