Report of the Statu Geologist. 225 



conflicting views are still entertained regarding the stratigraphical 

 relations of important formations. The difficulties in this region have 

 arisen from two causes. We have a set of slates and argillaceous 

 sandstones, known as the Hudson river group, occupying a portion of 

 this area. In absolute juxtaposition with these are a series of much 

 older slates and limestones, which have been brought up to their 

 present position by deep-seated geological movements. , The later 

 erosion of the surface, with the covering of gravel, sand and clay, has 

 obliterated, or concealed for the most part, the lines of junction, and 

 the two series, so distinct in. age, have been regarded as a single 

 formation, and were thus colored on our first geological map. 



Still further eastward are a series of crystalline schists and lime- 

 stones, which are regarded as the metamorphic condition of the 

 Trenton limestone and the shales of the Hudson river group. The 

 true limits and extent of these several formations, on the east side of 

 the Hudson river, have not yet been determined, and for the present 

 the map must remain only partially colored over this part of the 

 country. 



In the region of the Catskill mountains, both on the southeast and 

 northwest, there are portions of country where the absolute limits 

 and order of succession among strata have not been fully settled; 

 and further investigation is required. The smaller areas in the south- 

 western portion of the State may be completed with less labor, as we 

 shall have the results of the county surveys in Pennsylvania to com- 

 pare with our own work in this part of the State. Some contributions 

 to the limits of certain formations in the southwestern part of the 

 State have been made by Mr. C. E. Beecher, of the State Museum, as 

 the res\ilts of his own observations and those of Mr. F. A. Randall, of 

 Warren, Penn. 



During the last year, 1884, some work was done in Otsego and 

 Chenango counties, with a view to comparison and verification with 

 the work done in that region between 1868 and 1871, by Dr. J. W. 

 Hall and Mr. George B. Simpson. 



In the autumn of last year, I employed Mr. C. E. Hall to make some 

 investigations for rectifying the limits of the geological formations 

 in Saratoga, Warren and Washington counties, which were known to 

 be incomplete and erroneous in their representation on the map. 

 This investigation was interrupted after a month of field-work, and 

 the results, while contributing to our knowledge of the limits and 

 extent of certain formations, showed more cleai'ly the necessity of 

 further examination before any reliable geological map of that part 

 of the State can be completed. 



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