New York State Museum Bulletin 



Entered as second-class matter November 27, iQiS, at the Post Office at Albany, New York, 

 tmder the act of August 24, 1912 



Published monthly by The University of the State of New York 

 No. 191 ALBANY, N. Y. November i, 19 16 



The University of the State of New York 

 New York State Museum 



John M. Clarke, Director 

 GEOLOGY OF THE VICINITY OF OGDENSBURG 



BY H, P. GUSHING 



INTRODUCTION 



The chief purpose in mind in undertaking the areal mapping of 

 the district here reported upon vi^as to make a careful study of the 

 Beekmantov^^n formation in the district of the upper St Lav^rence, 

 in order to see how^ fully it v^as represented and how^ it compared 

 vv^ith the formation in the Champlain valley. Betv^^een Ogdensburg 

 and Morristov^n excellent section^ of the formation are shown so 

 that, in so far as the lower portion of the formation is concerned, 

 the work was very successful. Down the river from Ogdensburg, 

 however, the glacial drift is very widespread and heavy, and rock 

 exposures are infrequent and scant; so much so that it is highly 

 questionable whether a satisfactory idea of the higher beds of 

 the formation can be obtained. 



Prof. G. H. Chadwick was engaged in mapping the Paleozoic 

 rocks of the Canton quadrangle, at the same time that our work 

 was in progress, giving opportunity for us to keep in touch with 

 each other, and to make a definite comparison of results. This 

 has proved of especial help since, owing to heavy drift, the rocks 

 east of Ogdensburg on the Ogdensburg quadrangle are almost com- 

 pletely covered up, and a formation wedges in there and appears 

 strongly on the Canton quadrangle, where Professor Chadwick 

 recognized it, which would probably have entirely escaped our 

 notice on Ogdensburg. 



In 1913 both Dr E. O. Ulrich and Dr R. Ruedemann spent two or 

 three days with me at Ogdensburg, looking over the section with 

 me and giving indispensable assistance. They have also spent 

 much time in determination of the fossils collected, hence a large 

 part of such merit as the report may have is owing to their aid. 



