296 



Report of the State Geologist. 



but adjacent to the walls and in the smaller dikes and the overflow layer 

 it has decomposed and is now very soft and friable and greenish yellow in 

 color. The main dike is exposed also on the south side of Green street, but 

 for only a few rods south of that point. It extends in a northerly direction 

 across James street, and has been traced by Mr. P. F. Schneider as far as High- 

 land street, a distance of a little more than a quarter of a mile. 



A water pipe ditch dug near the west line of lot No. 805 James street, 

 and another on the premises of Mr. Hiscock on the opposite side of the street 

 exposed, and was excavated through, the decomposed overflow layer of this 

 eruptive to drab limestone beneath. The excavation for the foundations of a 

 barn on Green street, six rods east of the main dike, exposed a layer of the 

 same character, ten inches thick, spread over the shaly limestones. Grading 

 Elm street, which runs parallel with the dike nearly one-half mile to the east, 

 has exposed the rocks, and shows that the inclination of the strata corresponds 

 to the general slope of the hill. 



The position of the dikes as exposed at Green street is on the southwest 

 slope of the hill, and sixty feet higher than the low land at the south. The 

 elevation increases somewhat toward the north. Evidences of the eruption 

 have been found in this place, over a section one hundred rods in length 

 and twenty to twenty-five rods in width. 



The occurrence of the eruptive rocks in this region was first recorded by 

 Yanuxem (Annual Report, 1839 ; Final Report, 1842) and Beck (1842). The 

 original locality " on the Foot-street road to the east of Syracuse," was lost 

 sight of, and the rock was afterward known only from the few specimens 

 which had passed into the collections of some of the older educational insti- 

 tutions. From such material its nature was studied and its eruptive character 

 demonstrated by the late George H. "Williams (A.7neric<m Jowrnal of Science, 

 1887, and Bull. Geolog. Society of America, Vol. 1). A new exposure of this 

 rock was brought to notice by Mr. Schneider, in 1895, at DeSono station on 

 the West Shore railroad, about one-half mile south of Dewitt Center, and 

 an account of its occurrence and nature published by Messrs. Dai ton and 

 Kemp ("A Newly Discovered Dike at Dewitt, near Syracuse, New York. 

 Geologic Notes by N. H. Darton. Petrographic Description by J. F. Kemp" • 

 American Journal of Science, vol. 49, pp. 456-462, 1895). 



On account of the disturbed condition of the strata, any figures given in 

 regard to the dip can be only approximately correct. From data gathered 

 from the records of the Solvay Process Co.'s wells at Tully it was found that 

 the upper surface of the Corniferous limestone has a southward dip of forty 



