34 Report of the State Geologist. 



river in a brief report and map by Mr. C. E. Hall, published in 

 1886.* 



Besides the faults which extend to the Mohawk, there are a 

 number of others northward, of which several are important, and 

 there is a series of prominent dislocations in Saratoga county. 

 It has been know^n for many years that the springs at Saratoga 

 rise along a fault plane, and some features at this locality were 

 described by Matherf and Emmons.J 



General Relations. 



The sedimentary formations of the region are a succession of 

 sandstones, limestones and shales lying,§ on a floor of crystalline 

 rocks. They dip to the southward and south westward at a very 

 moderate rate, constituting a general monocline. The amount 

 and direction of the dip is not uniform, but the variations do not 

 materially affect the general relation s. The faults traverse this 

 general monocline and give rise to wide offsets in its regularity, 

 and local tilting of greater or less amount. Adjacent to the 

 fault planes there are also certain features of local disturbance, 

 such as upturning of the beds on the down-thrown sides. The 

 distribution and relations of these faults are indicated in the map 

 and in plates 2 and 3. In plate 2 I have attempted to represent 

 the relative positions of the fault blocks restored or bared at the 

 ideal surface of the Trenton limestone. In A and B, plate 8, 

 cross-sections are given, indicating the principal features along 

 the Mohawk Valley and along a zone about eight miles north, 

 respectively.. From these illustrations it will be seen that the 

 faulting seems to have taken place along vertical planes, and to 

 have been accompanied by a sharp drag of the strata on the 

 down-thrown side of the blocks. In the following pages the 

 evidence on this point will be given in detail, with a description 

 of the features of the several faults. 



The occurrence of crystalline rock at Middlaville has given 

 rise to a supposition that there is a fault at this locality. Owing 

 to the existence of this view I have made a careful examination 



* Field notes on the Geology of the Mohawk Valley, Fifth Report of the State Geologist for 1885, 

 pp. 8-10. (See note at end of this paper.) 



t Geology of New York, Part I. Comprising the Geology of the First Geological District, 1843. 



t Agriculture of New York, by Ebenezer Emmons, 1846. 



§ A description cf these formations was published in the Report of the State Geologist for 

 the year 1893, pp 409-429, plates 1-14. Albany, 1894. 



