Miller ton-Fishkill Limestones. 151 



Dutchess Co., in two main belts, the western or Pine Plains — 

 New Hamburg belt, and the eastern, or Millerton-Fishkill 

 belt. Associated with these are a few shorter parallel belts of 

 limestone. The western one has been considerably altered by 

 metamorphic action, but the metamorphic alteration has been 

 much greater in the eastern belt where the limestones are fre- 

 quently found coarsely crystallized and marble-like, while the 

 associated shales often merge into micaceous or hydro-mica- 

 ceous schists, or even become gneissoid. These facts were 

 clearly set forth by Professor J. D. Dana, in 1879,* as also the 

 fact that Lower Silurian fossils had been discovered in the 

 western belt, while no definite species of fossils had been 

 made out among the signs of organisms found in the eastern 

 one. 



Recently the writer visited the northern end of the Miller- 

 ton-Fishkill belt, for the first time, in the work of explora- 

 tion, entering it from the central part of the Shekomeko 

 Valley. The limestone was reached at the eastern base of the 

 high ridge of argillite and micaceous schist which is the south- 

 ern extension of Winchell Mountains. At once the presence 

 of fossils was discovered in a limestone ledge on the farm of 

 Mr. Edward Clark. The locality is a little less than a quarter 

 of a mile from the village of North East Center, on the Shek- 

 omeko road, and scarcely more than one and a half miles, in a 

 straight line, from Millerton railway station. It is about five 

 hundred feet northerly from the road, and but slightly elevated 

 above the surface ; the portion exposed is about one hundred 

 and fifty feet long and sixty feet wide, with a strike N. 11° E. 

 (true) and dip 35° westerly. 



The rock is a fair sample of the much altered limestone of this 

 eastern belt ; its color varies from gray to white, and in many 

 spots it is rather brittle, or inclined to crumble under blows 

 of the hammer. In some cases, where the mass of the rock is 

 grayish, the fossils in it are quite white, making a fine contrast. 

 This f ossiliferous limestone is frequently filled with films which 

 very strongly resemble micaceous or hydro-micaceous films ; 

 but as I have not had time to examine them carefully I do not 

 venture to assert that they are any other than films of gypsum. 



The limestone in this ledge is filled with organic remains, 

 some of which are fairly well defined, appearing in relief on 

 the weathered surfaces ; — many of them are distorted by pres- 

 sure. The so-called Calciferous fucoids are abundant and of 

 the same peculiar forms elsewhere observed in this formation. 

 Ophileta complanata (which according to Prof. R P, Whit- 

 field is identical with 0. compacta), is present in numerous 



* This Journal, vol. xvii, May, 1879. 



