288 GEOLOGY OF THE THIRD DISTRICT. 



The Onondaga limestone is more persistent, but the quality varies greatly, though the 

 parts exposed may not be fair samples of the parts which have never been uncovered. It is 

 extensively worked at Auburn, the facings of many of the houses being entirely made of it. 

 It is the stone, upon which the convicts at the prison are employed. It is readily traced 

 along its range to Springport, the last point where it was seen being above Blanding's lime- 

 stone quarry on the lake shore. 



The ■Comiferous limestone is extensively quarried at Auburn, at the quarry at the outlet ; 

 the upper quarry of the New- York Company ; the extensive quarry of Mr. Buhr ; and those 

 further to the east, upon the top of the water lime and the Onondaga limestone. Its cha- 

 racter, from its nodules of flint, is well exhibited in all these quarries ; the upper part showing 

 from eight to ten parallel ranges in a thickness of about three feet. Below the flint, there is 

 usually about twelve feet of good solid stone ; the layers varying from one to three feet thick, 

 and from nine to twelve feet much mixed with shale, and unsuitable for quarrying. Fossils 

 are more abundant in this portion than in the layers above. The same order of arrangement, 

 as to the nature of the rock, exists at Cherry- Valley, showing how general the action was 

 along the whole course. The color is darker, however, at Auburn, the upper layers being 

 almost black where fresh quarried ; but the vertical joints are equally well defined, giving a 

 work-like character to all its quarries. The comiferous forms the upper terrace at Auburn, 

 the seneca being concealed by alluvion, and must be in the rear, the flinty layer forming the 

 surface mass. There was no part of any extent uncovered, to ascertain if water-worn and 

 scratched. 



At Springport, to the south of the village, the quarry of Mr. Ham is opened in this rock. 

 It is in thick and thin layers, the latter used for flagging. Between the layers, there is shale, 

 the whole of a black color. At a higher level, a little to the south, is Howland's quarry, 

 showing the upper part of the comiferous, with its nodules of flint, upon which is the Se- 

 neca limestone ; the layers of both inclined at an unusual angle, being about 20° ; their 

 vertical joints proving that the change in the dip was anterior to the existence of the joints, 

 these in all rocks yet noticed being vertical. 



The Marcellns shales are exposed along the outlet from the main street in Auburn toward 

 the lake, numerous septaria having been thrown out in deepening and enlarging some portions 

 of it. They are seen in a few places, but obscurely, along the range towards the south of 

 Springport ; but in that section are more readily mistaken for those of the group above, from 

 the increase of finer materials to the west. 



The Hamilton group covers the greater part of Owasco, the northern part of the towns of 

 Sempronius and Fleming, the northern part of Scipio, those parts of Springport which border 

 on Fleming and Ledyard, the greater part of Ledyard, and all that part of the county which 

 borders on Cayuga lake to the south of Ledyard, the breadth diminishing south ; also the valley 

 at the head of Owasco lake, extending south towards Milan. The finer kind of shale predomi- 

 nates in the county, showing some impure limestone, a mass of which appears in the bank on 

 the lake to the north of Levana ; the same being seen in the brook at Mr. Crise's, about two 

 miles south of Springport. The coarser kind, and none of which was sufficiently so for a 



