236 



Report of the State Geologist. 



furnishing a datum from which the location of the sandstones on the plateau 

 may be ascertained with a ffood degree of accuracy. At the south end of the 

 Tonawanda Creek valley and in the vicinity of North Java and Java Center 

 the sandstones are covered by drift. 



In a deep ravine two and one-half miles north of Strvkersville, cut 

 through the lower soft shales, some heavy layers of sandstone aggregating 

 fifteen to eighteen feet in thickness, occur at the top of a cascade know n as 

 Johnson's falls. They are very compact and present exactly the same 

 appearance as the upper l>cd>. 



The upper stratum, about eight feet thick, is exposed at Java village, in 

 the bed of the stream, where it crosses the main street. In the ravine above, 

 there appear first about twenty-five feet of black fissile shale, then seventy-live 

 feet of soft, blue shale, in which the small concretions abound ; then sixty 

 feet of typical upper Portage flags and hard shales to the bottom of the upper 

 sandstone beds. 



In the northern and western parts of the town of China, the rocks are 

 covered by drift; but in the southwestern part, near the village of Arcade, 

 in the Cattaraugus creek valley, the upper sandstones are exposed in a quarry 

 that has been operated for many years. The rock section is about twenty feet 

 thick. Some of the layers are very hard and compact, others are rather 

 schistose. These beds arc quite barren, but on the road leading eastward 

 from the village, Chemung fossils are common at an horizon of fifty feet above 

 that of the quarry. 



Westward from Arcade, the upper limit of the Portage group is found in 

 the high hills on the south side of the valley of Cattaraugus creek, with exten- 

 sions towards the south in the numerous lateral valleys. 



There are probably some thin outliers of Chemung rocks of small area 

 on the north side of the valley in Erie county. 



The upper Portage flags and sandstones are exposed along Walnut creek, 

 in Arkwright, and in the bed of Canada w -ay creek, at and above Laona, where 

 one compact layer, four feet thick, and another three feet thick that splits 

 easily into flags, are quarried, The compact layer is also quarried near 

 Brockton, and in the village of Westfield. It disappears beneath the waters 

 of Lake Erie, about three and one-half miles southwest from Westfield. 



The Portage sandstones, so well defined in Livingston and Wyoming 

 counties, in their westw ard extent gradually lose their heavy bedded character, 

 and in the vicinity of Lake Erie they are composed mainly of thin sandstones 

 separated by thin layers of hard shales. 



