444 



Repobt of the State (xeologist. 



One-half mile to the north is an outcrop of shale along the roadside by 

 an old barn. It occupies a small triangular area. Above it on the hill the 

 Cambrian limestone appears, as well as t<> the north of it in a quarry l>v Mr. 

 Rose's house. At this latter locality the dip is t<» the southeast. The exact 

 relations are here again obscured by the drift, but the Trenton may rest on 

 the Cambrian, and the Hudson river shales may rest either on the buried 

 Trenton or directly on the Cambrian, by thinning <>ut of the Trenton or by 

 faulting. 



To the southwest of Balmville, which is on the northern edge of 

 Newburgh, the limestone again begins and extends, as an elliptical area of 

 four miles in length, in a southwest direction to Washington lake. The 

 width of the area is about one mile and a quarter. To the northwest it rests 

 on the Olenellus quartzite, and this in turn on the gneiss of Cronomer's hill. 

 The rest of the distance it is overlaid by the Hudson river slates. On the 

 southeast, the limestone dips in part under the slates, and is faulted against 

 the steep northwestern' side of Snake hill. The dip of the limestone is 

 generally southeast. There is doubt whether all of the limestone of this area 

 is of the same age. Over the larger portion of the area it is a crystalline, 

 cherty limestone, very much resembling that of the other Cambrian areas, 

 but in the southeastern part, in Miller's quarry, the rock is more evenly bedded, 

 and less massive. 



Some years ago Professor E,. P. Whitfield published the discovery of 

 piobable Mad a n (is in parts of the limestone. This indicates the Chazy age 

 of a portion of the limestone, the greater part of which is probably Potsdam, 

 according to an opinion expressed to the writer by Professor Dwight (See 

 also. A. -/. S., iii , XVIII., 327, 1879). The specimens were fragmentary, and 

 none have since been found. Professor W. B. Dwight informs the writer 

 that he has found a few ill-defined Calciferous fossils in the limestone of 

 this area northeast of Washington lake. 



Southeast of Washington square, the Hudson river slates extend around 

 the south end of the limestone area and rest uncomformably against the 

 gneiss at the south end of Snake hill. The slate crops out along the road at 

 the southern end of the hill (4<>7a), and extends along the east side of it, 

 appearing at several points, and especially on Mr. Hasbrouek's race-track, 

 where it has a strike of N. 40° E. and dips west. Farther south along the 

 road, the dip is east. The slate is also seen at the north end of Snake hill, 

 at 215 feet A. T., along the road leading to the pavilion on the summit, and 

 along the road by the ice-house at the northwest base of Snake hill. The 



