18 



Report of the State Geologist. 



A large part of this report is especially concerned with the product of 

 natural gas and records of the wells which have been drilled in and 

 about the city of Buffalo. This account has been prepared with elaborate 

 care, giving a full list of the gas-producing companies or individuals, their well 

 records and product. The tabulated list of wells, productive and non- 

 productive, embraces sixty-seven. These statistics are supplemented by some 

 discussion of the geology and supply of natural gas. Brief accounts of the 

 rock salt and water power of the county are followed by the description of 

 a general geologic section from Lake Ontario to Cattaraugus creek. 



The paper is accompanied by a geologic map of Erie county, with several 

 maps showing the location of the gas wells, and by numerous photographs. 



Report on the Geology of Orange County. 



By Heinkich Hies. 



The introductory parts of this report are devoted to a description of the 

 physical geography and topography of the region, followed by a summary of 

 geologic literature pertaining to the district. 



The geologic formations present are then taken up in consecutive order 

 for brief discussion. 



The j •re-Cambrian rocks are largely developed, consisting of gneisses, 

 gneissoid rocks and limestones, all frequently traversed by dykes of igneous 

 lock. The bodies of iron ore which are worked in this county lie in these 

 crystalline rocks. 



The Cambrian r< >cks are light colored, generally heavy bedded magnesian 

 limestones, and though apparently without fossils, they seem to be a con- 

 tinuation of the limestones of northern New Jersey, in which fossils have 

 been found. These limestones frequently become crystalline as a result of 

 granite intrusions. 



The Trenton group is represented only by a single exposure near New- 

 burgh. The Hudson river shales and sandstones are very widely extended 

 ami cover nearly two-thirds of the area of the county. In a few localities 

 they have furnished fossils. In the Shawangunk mountains, the Medina sand- 

 stone has a thickness of about fifty feet in the town of Deer Park, and "also 

 appears in the vicinity of Skunnemunk mountain. The Lower Helderberg 

 series appeals at several points, and at the best exposures its different mem- 

 bers can be determined. The Oriskany sandstone and quartzite occurs in two 



