224 Forty-third Report on the State Museum. 



building or ornamental use; the position and extent of the hydraulic 

 limestones; the gypsum and salt beds; the extent and geological 

 relations of the various iron ores; and of all other materials entering 

 into daily use in civilized life. 



To the schools and colleges of the State, such a map "would be of 

 inestimable value. A copy of the map should be placed in every 

 school-room, in order to familiarize the pupils with the nature and 

 geographical distribution of the rocks and the economic products of 

 each. This would give more rational knowledge regarding the State 

 and its resources, than could be derived from any other method of 

 teaching whatever. 



At the present time, a finished geological map is impossible, because 

 of the deficiencies in our knowledge. A few examples may be given 

 in illustration. We know that the Adirondack region is occupied, 

 to a very great extent, by what is known as the Laurentian sys- 

 tem of rocks, which consist of gneiss and granite, which in their 

 lower divisions, carry extensive beds of magnetic iron ore; while the 

 upper portions, consisting of granitic rocks of a different character, 

 known as Labradorite, carry beds of titaniferous magnetite. No 

 one has yet shown the limits of the area occupied by each of 

 these divisions, or their true relations to each other; and yet this 

 knowledge is of the highest importance in regard to the future 

 product of the valuable ores of this part of the country. The mag- 

 netic ores of the lower portion of the system are extremely important, 

 and give an immense revenue to the owners of the mines, while those 

 of the upper portion have not hitherto been wrought to advantage. 



When we come to the boundaries of this great Laurentian area, we 

 can not speak with cei'tainty of its limitations, especially upon the 

 northwest and west. There the rocks of this age are succeeded by 

 another set of crystalline rocks, consisting of granitic masses, with 

 crystalline limestone, with breccia or conglomerate, and carrying 

 extensive beds of red hematcle ore. This is largely consumed in the 

 iron furnaces, in connection with the magnetic ores. But although 

 of such immense importance, and so positively distinct in lithological 

 aspect and economic pi oducts, the limits of the two formations have 

 never been indicated with any degree of exactness. 



On the southern and southeastern slope of the Adirondack region, 

 the country is greatly disturbed by a succession of faults, which 

 render geological work slow of accomplishment, and the difiiculties of 

 indicating the limits of the succeeding formations are great. 



On the east side of the Hudson river, from Vermont to the High- 

 lands, the relations of the several formations are in doubt, and very 



