8 Bulletin of the New York State Museum. 



the Champlain valley. Therefore the grouping by geological rather 

 than by geographical lines alone, is more definite, and the larger dis- 

 trict of the Adirondacks is better than any subdivisions according to 

 our present knowledge. It is a notable fact that nearly all of the 

 mines are on the borders, and that comparatively few ore localities 

 have been found in the interior. A reference to the map of the State, 

 with this report, shows the location of the mines and mine groups. 

 The explanation of their distribution is the greater accessibility of 

 the outer part of the region to lines of transportation and its more 

 thorough exploration. Prospecting for iron ore in the forested and 

 more distant interior is difficult, and besides, is not stimulated by 

 any hope of adequate return, excepting in case of large deposits 

 which, from their extent and character of ore might warrant the 

 construction of branch railway lines, as at Chateaugay, Clifton, Jay- 

 ville and Little River. Future explorations will, doubtless, discover 

 many iron-ore beds, and result in the development of other mining 

 centres in what now appears as barren ore-territory. The con- 

 struction of additional railways, affording facilities for reaching the 

 markets, will do much to open and develop new mines. 



The titaniferous nature of the magnetites, which have been found 

 in the Labrador series, as for example, at Splitrock, in Westport, 

 and at Adirondack, in the town of Newcomb, Essex county, has 

 retarded mining in the localities where they occur. 



The difficulty and expense of reducing the ores containing consid- 

 erable titanium, and the failures in the way of practically separating 

 the titanic minerals from the magnetite, have shut them out of the 

 iron-ore market, and the mines having such ores only, have been idle 

 for years. That all the magnetic iron ore occurring in this geological 

 horizon is alike titaniferous, does not appear to be proven by the 

 comparatively few ores analyzed from limited areas ; and there is 

 hope that ores sufficiently low in titanium for successful working, 

 may be found. 



The strike or course of the iron-ore beds in so large a district is 

 affected by all the local variations in the positions of the enclosing 

 strata. In general, the direction is north-east and south-west. The 

 dip is also at all angles, varying from a horizontal to a vertical. 

 Much further study of the geological structure is needed to explain 

 the features which the mines have exposed to view. The immense 

 deposits at the Port Henry mines, the many separate beds of the 

 Crown Point mines, the dikes and faults at Palmer Hill, the parallel 



