BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol. 26. pp. 287-294 JUNE 30, 1915 



POST-ORDOViriAN DEFORMATION IN THE SAINT 

 LAWRENCE VALLEY, NEW YORK ^ 



MY GEORGE II. CHADWR'K 



{Presented before the Society Decenttier 31, UUJi) 



CONTENTS 



T'ase 



I iitroductury L'S? 



(ienerul stratigraphy of the area "JST 



Form and character of the folds •_'!)() 



Time and cau.se of the fohlini,' lllti 



Introductory 



That the Paleozoic rocks of tlie Saint Lawrence Valley are gently 

 uiidulatdTy is no new aiiiiouiicenu'nt. tlion^li it may be so regarded for 

 tlu' area iniincdiately under discussion, namely, the Cauton, New York, 

 topographic (juadraugle. These undulations were described on the C'aiui- 

 dian side of the river as early as 1863 by Logan,- and again more re- 

 cently by Cushing for tlie Watertown district^ on the New York side. 

 Tile present j)a|)er I'ccords tlieir extension into the Ogdensburg-Canton 

 (|iia(li'angles and discusses tlie evidence as to their origin and their rela- 

 tion to thi' beds of pre-(_'and)rian rocks beneath. The location of the 

 two ipiatlranglcs is indicated on the kcsy map, figure 1. 



(IknI'M.'ai, S'ii;APi(;i;Ai'in- oi- thk Arka 



Thouiih tbe connti'v is bea\ily ilri ft-niantled, yielding few exposures. 

 wlien tbe hitter ai'e |»lotte(l and connected up with regard to strike and 

 to to|>ogra|)liy there I'esults a pattern of outcrop sufficiently complicated 

 (and lil<ely to be found more so on remo\al of the drift) to denote the 

 presen(;e of two I'et ii-ulat in^' sets of folds liere as in tlie Thousand Islands 



' Manuscript received liy ilu* Secretary of tlie Society May 6, lOlfi. 



Witli permission of lln' Iiiiccloi- of the Now York Stat(> Mnseiiiii. 



= Sir Willinm K. liOKaii : "(JcoloKy of Caniuia." p|i. '.M. !M, '.Ml. IN. lid. 117. etci'ii-ra 



■' I'l-iif. II. I'. Cnsliiiii;: I'.iiii. ll.'i, .\. V. Slalc .\lusriim, |ip. I'd. li:;. l.'ir.-l. ■',(>. 



( 2S7 I 



