526 PROCEEDINGS OF THE WASHIXOTON MEETIN(r 



parting between. The pebbles are mostly of vein quartz, and the great majority 

 of them are distincth- flattened like those of the Wolf Creek, and, like the latter 

 also, they include an occasional one of red jasper. The maximum thickness in 

 the Olean-Salamanca region is rarely over 30 feet, and probably never exceeds 40. 



Much confusion and uncertainty has arisen in the Salamanca region as to the 

 number of conglomerates present beneath what has generally been called the Sub- 

 Olean. This is especially true of that region bordering the valley of the Tunang- 

 want or Tuna. Various correlations, some of which, however, were recognized 

 as provisional, have been made for the same outcrops, and different outcrops of 

 the same conglomerate have often been regarded as belonging to difierent horizons. 



The names Salamanca, Panama, Pope Hollow, Wrightsville, and even Sub- 

 Olean (?) have all been applied in this region to the same conglomerate, some of 

 them being regarded by some as synonymous, but the belief being prevalent that 

 two or three conglomerates are present in the Tuna section. 



The lower conglomerates found bj'^ Randall * northeast of Carrollton and up 

 Baillett brook, and perhaps in a few other neighboring localities, is the Wolf 

 Creek, here locally much thickened as compared to its usual development in tliis 

 region. His higher conglomerate is the Salamanca, 



The Salamanca, the Panama, the Pope's Hollow, and the Tuna are the same 

 conglomerate, and Lesley's! supposed third or Sub-Olean (?) conglomerate at Ire- 

 land, near the head of Irish brook, is also an excellent outcrop of the Salamanca. 

 The confusion has mainly resulted from assuming a regular dip for the Salamanca 

 and then concluding that a conglomerate found too high or too low at a given 

 locality for the calculated position of the Salamanca at that place belonged to a 

 different horizon. Dips, however, are not regular in this region, and such dip 

 calculations are misleading. 



Kilhuck conglomerate lentil. — On the Salamanca sheet there is found locally devel- 

 oped in the Cattaraugus formation a third conglomerate lentil lying 50 to 70 feet 

 above the Salamanca conglomerate and called by Mr Fuller the Kilbuck. It has 

 much the same flat-pebble character as the underlying Salamanca. It is not over 

 10 to 15 feet thick as a maximum, but in places is quite massive and weathers into 

 large flat blocks that, w^iere topographic conditions favor, form a pavement over 

 considerable areas. It is best developed northeast and east of Kilbuck. Though 

 its areal extent is not great, it has possibly added to the difficulties of making cor- 

 rect correlations in this region. 



Probable unconformity. — The top of the Cattaraugus formation is diflicult to deter- 

 mine with exactness in most places, since its upper portion consists of soft shales 

 and it is succeeded by other soft shales. Exposures are in consequence poor, ex- 

 cept along roadways or pipe lines. Numerous measures, however, that are deemed 

 reliable have been obtained of the thickness of that part of the formation which 

 lies above the top of the Salamanca conglomerate lentil. A comparison of these 

 figures shows that this thickness frequently varies irregularly and very materially 

 within short distances. It is not thought probable that mere local variations in 

 the thickness of the strata of the Cattaraugus could be rapid enough and great 

 enough to account for this irregular variation. It seems more probable that the 



*F. A. Randall : Preliminary Report on Geology of Cattaraugus and Chautauqua Counties, in 

 Report of State Geologist of New York for 1892-1893, pp. Tia-721. 

 fj. P. Lesley: Sum. Fin. Rept. Pa. Geol. Survey, vol. ii, pp. 1531-1532. 



