FOURTH REPORT OF THE DIRECTOR I907 3 1 



trine silts and sands of the Mohawk valley, the gravels and sands 

 of the Lake Albany and Iroquois stage, and the lacustrine clays of 

 Lake Schenectady. Postglacial modifications of the glacial deposits 

 are conspicuous along the valleys of the Mohawk and the Schoharie. 

 Curiously along the Mohawk there is nothing that can be called 

 .ordinarily alluvial terrace. Meanders are practically absent while 

 along the Schoharie terraces meanders and abundant oxbow chan- 

 nels are typical and conspicuous. These differences point to radical 

 differences in the history of the major valley as compared wdth 

 that of its tributary, and these differences have to do, it would 

 seem, with the marked lacustrine conditions and great lake outflow 

 that belonged to the Mohawk valley. As already intimated the 

 conclusions here announced by Professor Brigham and the hypothe- 

 sis suggested need explanation and confirmation by close study 

 of surrounding areas. It is desirable to know the westward and 

 southern limits of the Mohawk lobe. From the general appear- 

 ance of the topography it would seem that the powerful glaciation 

 of the Mohawk region must have ceased not far south of ihe 

 boundary of the present area. The map of the Berne quadrangle 

 south of the Amsterdam quadrangle seems to show interesting con- 

 ditions which it has not been possible to study in the field. Near 

 the middle of the quadrangle there is a conspicuous bifurcation in 

 the trends of the drumlinoid or linear forms of topography, indi- 

 cating apparently a push to the west as a part of the flow of the 

 Mohawk glacier already described, and a push to the south along 

 the lines of the Hudson valley. It is conjectured that a study of 

 this area in the field will show corresponding directions of the 

 glacial striae and that here may perhaps be found a point of con- 

 spicuous divergence between the Mohawk and Hudson river lobes 

 of the glacier at a certain stage of their activity. 



Industrial geology 



Mines and quarries. The third of the series of annual bulletins 

 reviewing the progress of the mineral industries in the State was 

 published in July of the current year. There is a steady demand 

 for information relating to the mineral resources, such as is given 

 in these publications, and the continuance of their issue seems ad- 

 visable. 



The statistics collected for publication in the report indicate a 

 material growth in the importance of the mining and quarry in- 

 dustries during recent years. The total output of all materials re- 



