GEOLOGY OF THE SCHROON LAKE QUADRANGLE 71 



that the mid-Ordovician sea spread far enough westward to cover 

 at least the eastern part of the Schroon Lake quadrangle. 



We have no positive evidence that any part of the Schroon Lake 

 quadrangle has ever been submerged under sea water since mid- 

 Ordovician time. 



Fig. 6 Map of northern New York showing the general relations of 

 land and water during parts of the Cambrian and Ordovician periods. The 

 whole shaded portion represents land during the late Cambrian time, and 

 the cross-lined portion represents land during the middle of the Ordovician. 



STRUCTURAL GEOLOGY 



Structure of the Grenville Series 



Tilting and folding. Evidence has recently been presented by 

 the writer 1 to show that the Grenville strata of the Adirondacks 



1 Jour. Geol., 24 1588-96. 1916 



