Lutheb — Economic Geology of Onondaoa County. 



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in the horizon of the middle of the Corniferous strata, shows a section of 

 tw elve feet in even compact layers one to two feet thick. One layer of blacfc 

 chert two inches thick is persistent. 



Many prominent buildings in the city of Syracuse have been built of 

 Onondaga limestone. Among them are the Onondaga County Court House, 

 on West Genesee street, built in 1857; St. Mary's Cathedral, built in 1874 ; 

 Reformed Protestant Dutch Church, on James street, built in 1884; May 

 Memorial Church, on James street, built in 1884; St. Paul's Cathedral built in 

 1884; the Post-Office building, on East Fayette street, built in 1884; the W. 

 S. Peck block, on West Water street, built in 1887; the City Hall, on East 

 Washington street, built in 1 892 ; the Onondaga County Savings Bank, 

 corner of Salina and Genesee streets ; the Hall of Languages, Syracuse Uni- 

 versity; Senator Horace K. White's residence on James street, one of the 

 most elegant in Syracuse, is built of medium-sized blocks of grey limestone, 

 laid in broken ashlar style. 



Hamilton Group. 



Overlying the Corniferous limestone, and constituting the surface rock 

 over nearly all that part of the county south of the great limestone ledge, 

 are the soft shales and tine thin sandstones of the Hamilton group, the 

 lowest division of which is the Marcellus shale, so named because of its 

 favorable exposure in the town of Marcellus. The transition is abrupt, the 

 black shale being in immediate contact with the grey limestone below. In 

 the lower seven feet it is more or less calcareous owing to the presence of 

 immense numbers of a minute pteropod, StyUolina fissurella, and at one 

 horizon indurated, forming a thin, non-persistent layer of very dark laminated, 

 impure limestone. Except in these calcareous portions, w here they are blue- 

 black, the shales are very bituminous and fetid, black with a brown streak, and 

 become rusty on exposure by reason of the abundance of iron in their com- 

 position, and fissile, with very thin laminae. Fossils, especially IdorhyneJms 

 limitaris, are. quite abundant in some of the calcareous layers. Thirteen feet 

 above the top of the Corniferous limestone there occurs the layer of hard, 

 dark impure limestone, about two feet, six inches thick, know n as the Gonia- 

 tite limestone on account of the abundance and great size of this fossil. 

 The stratum is usually composed of two layers, the lower one the thicker. 

 Adjacent to the shales the limestone is compact and even, but in the middle 

 part it has the appearance of being concretionary, and w hen broken presents 

 a rough, scraggy surface. 



