IB 



Report of the State Geologist. 



ing and handling, a list of producers and product and of the notable buildings 

 in Syracuse, affording illustrations of ' the usefulness and beauty of the rock. 



The Marcellus formation is considered, with especial reference to the de- 

 velopment of the Goniatite limestone. 



The shales and sands of the Hamilton group, covering the high lands of 

 the southern part of the district, are described, and notice , taken of all their 

 principal exposures. 



The Tnllv limestone, a highly important base line among the formations 

 in this region, is carefully traced throughout the county and its variations in 

 thickness measured. It has some value as quarry stone, and its exploitation is 

 described. 



A bed of black shale, overlying the Tully limestone and having a thick- 

 ness of 90 feet, is recognized as the continuation of the Genesee slate of 

 w estern New York, together with the bituminous shale beds occurring in the 

 lower part of the Portage formation in Ontario and Livingston counties. As 

 these black bands within the Portage shales are but sparingly fossiliferous -and 

 their species are for the most part unlike those of the true Portage fauna, the 

 assumption that the Onondaga county bituminous beds represent the completed 

 tendency of the ancient seas to such sedimentation at this period may be 

 probable, while its demonstration from sections would, in the paucity of fossil 

 remains, be more difficult. The Portage shales and sandstones appear only in 

 the tops of the high hills at the south, and bear a fauna characterizing the 

 Ithaca gr< nip. 



Under the caption, " Quaternary Era," the various surface modifications of 

 the county in late geologic time are considered. In this connection notice 

 is taken of clay, sand and marl deposits of economic importance, and of the 

 actual product therefrom. 



Following this is a discussion of the condition of the rock strata, w ith 

 (•special reference to dip, folding and faulting, with citation of illustrative 

 phenomena ; and much interest attaches to the author's account of the peridotite 

 eruptive dikes in the city of Syracuse, first discovered by Vanuxem, and 

 carefully studied in Liter years by G. H. Williams, and afterwards by Darton 

 and Kemp. 



The report closes with a statistical table of all economic products of the 

 county, w ith names of producers and amount and value of output. 



The report is accompanied by a geologic map of the county, various 

 smaller maps, diagrams and sections, and numerous photographs. 



