period, the rocks that underlie it and rib its hills, give us more fully 

 and perfectly its history before that period. The oldest formation of 

 Chautauqua County is known as the Portage. It forms the surface 

 in its northern portion, extending from the shore of Lake Erie high 

 up along the remarkable ridge that extends easterly and westerly 

 through the northern part of the county. Above the rocks of the 

 Portage group lie the rocks known as Chemung. These rocks spread 

 over the whole southern part of the county. 



The Panama and Salamanca conglomerate compose the upper 

 strata of the Chemung group, and are the last formed of the strati- 

 fied rocks of Chautauqua County. Great fragments of it lie scat- 

 tered at wide intervals over its southerly portion. In Harmony, at 

 Panama, at the celebrated city of rocks, it exists in huge masses 

 sixty or seventy feet thick, extending for more than one-half mile. 

 The northerly line of this formation extends southwesterly from the 

 hills of Arkwright across Chautauqua Lake near the narrows through 

 the southwestern towns of the county into the State of Pennsyl- 

 vania. To the southward east of this line, at various points upon 

 the hills, are scattered blocks of Panama conglomerate and its under- 

 lying sandstones. Northwest of this line but little evidence remains 

 of its former existence. Yet it is probable that it once extended as 

 far to the northwest at least as the northern face of the ridge, and 

 once covered the whole surface of the southern part of the county. 

 By the action of the glaciers, through the ice period its thinnest edge 

 has been worn away, or covered with drift and obliterated in nearly 

 all the southern portion of the county, wiping out with it all traces 

 of life in the carboniferous, mesozoic and tertiary ages — that vast 

 period of time that has elapsed since the devonian. The marks of 

 abrasion by the glaciers are often seen upon the upper surface of these 

 rocks. The direction of the ice scratches in the conglomerate at 

 Williams quarry, are nearly north and south. The dip of this rock 

 and other circumstances have led many to suppose that the Panama 

 conglomerate was the equivalent of the Venango oil sands, but close 

 observations of geologists (particularly of Prof. Carll) have proven 

 that it is neither the first, second nor third sands, but has an age 

 older than either. If this rock could be traced to the oil country 

 through the characteristic marks and fossils which it contains, it 

 would be found to lie the lowest of them. This formation, however, 

 is found, as it extends southerly, to quickly lose its identity and 

 merge gradually away into sandy shales; consequently the oil wells 

 that in this county, and at other points have been commenced in the 

 Panama conglomerate, or rocks beneath them, have been sunk in 

 rocks far below the oil bearing measures, with often a show, but 

 never in any instance, paying in quantities. 



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