Luthek — Economic Geology of Onondaga County. 



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tending into the deep valleys of Skaneateles, Otisco :iii<l Tully lakes, 

 Labrador creek, Keeney's creek and Limestone creek, <juite to the southern 

 boundary. Throughout this entire region of high hills and deep valleys, 

 'he rock is generally but thinly covered with drift, and the soil is largely 

 composed of disintegrated shales, especially along the sides of the hills. 



At the base of these Hamilton strata is a mass of soft argillaceous shales, 

 brownish or bluish grey, with layers of olive or light blue color; some thin 

 layers are bituminous. Calcareous concretions are not uncommon. Fossils 

 occur sparingly in the lower part, but more and more abundantly toward 

 the top. 



The thickness of this part of the Hamilton group, w hich embraces the 

 Ludlowville shales, is between 300 and 400 feet. It is exposed in the Lime- 

 stone creek valley, north of Delphi; also in the vicinity of Watervale, and in 

 the Butternut creek valley, in the vicinity of Onativia station, in the Onon- 

 daga creek valley north of Cardiff, and in many places in the southern parts 

 of the tow ns of Marcellus and Skaneateles. 



A large portion of the upper Hamilton rocks is composed of soft 

 shales, similar to those just described, but intercalated with them are beds 

 of coarser arenaceous shales and schistose sandstones in w hich fossils are 

 exceedingly abundant, masses of them supplying calcic carbonate sufficient to 

 cement the loose and rather friable material into firm hard rock. These hard 

 layers frequently appear on the sides of the hills, forming terraces and escarp- 

 ments distinguishable for long distances, and show plainly the southerly dip 

 of the strata. These terraces are developed to a remarkable degree on the 

 sid.es of the valley of Onondaga creek south of Cardiff, where six can be 

 distinctly seen on the west side. One of them rises as a bold escarpment on 

 the hill west of the village of Delphi. Several occur also on both sides of 

 the Otisco valley south of the lake, and in many other places 



The sandy layers are exposed at the top of Pratt's falls, and between 

 there and Pompey hill, and at Conklin's falls and Delphi falls, in Fabius in a 

 ravine west of the dam at the foot of the DeRuyter reservoir, also in the 

 valley between Fabius village and Keeney's settlement. The ravines about 

 Cardiff and in the vicinity of the Tully salt wells are excellent places in 

 which to examine them and to collect fossils, and the same is true of the 

 Otisco valley, particularly at the mouth of the Bucktail ravine. The 

 whole series of the upper Hamilton shales and sandstones is well exposed 

 at the south end of Skaneateles lake in the numerous ravines, and along 

 the shore. 



