52 H. B. KUMMEL 



Watchung trap sheets give us evidence of at least three periods 

 of eruption separated by long intervals of quiet, during which the 

 deposition of the shales went on as regularly as before. The 

 intrusive sheets were probably formed after the overflow sheets 

 but this has not been conclusively demonstrated. Since both the 

 intrusive masses (save perhaps some dikes) and the extrusive 

 sheets are cut by the faults, the volcanic phenomena preceded 

 the faulting. 



Professor Davis 1 has suggested that the disturbing force 

 which ended the deposition, was probably "a long enduring and 

 slow acting horizontal compression, exerted in an east and west, 

 or southeast and northwest direction ; and that the explanation 

 of the tilted and faulted structure is to be found in the writhing 

 and rising of the inclined layers of underlying gneiss and schist, 

 as they were subjected to this horizontal compression." The 

 foundation on which the Newark sediments rest would thus be 

 faulted and canted, and "the overlying beds, unable to support 

 themselves unbroken on this uneven foundation, settle down 

 upon it as best they may." This explanation, offered to meet 

 the conditions of the Newark beds of Connecticut, is fully appli- 

 cable in its general features to the New York and New Jersey 

 area. Henry B. Kummel. 



Lewis Institute, 



Chicago, January i, 1899. 



'Davis, U. S. Geological Survey. Seventh Annual Report, pp. 481-490. 



