BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



VOL. 27, PP. 531-554, PLS. 20-21 SEPTEMBER 13, 1916 



PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY 



SILURIAN FORMATIONS OF SOUTHEASTERN NEW YORK', 

 NEW JERSEY, AND PENNSYLVANIA- 1 



BY CHARLES SOHUCHERT 



{Presented before the Paleontological Society December 30, 191Jt) 



CONTENTS 



Page 



Introduction ^ 531 



Part 1 532 



Historical statement < 532 



The Medina series 534 



The Cayugan series 537 



Summary of sections nearly 300 miles apart 539 



Part II 540 



The Silurian sections 540 



Rondout, New York 540 



Binnewater-High Falls, New York 540 



Rondout Yallej r underground geology 542 



Green Pond Mountain, New Jersey 543 



Otisville, New York 544 



Delaware Gap, New Jersey-Pennsylvania 545 



Lehigh Gap, Pennsylvania 547 



Schuylkill Gap at Port Clinton, Pennsylvania 548 



Susquehanna Gap at Rockville (= Fort Hunter), Pennsylvania. . 549 



Jacks Mountain, Pennsylvania 550 



Tyrone Gap, Bald Eagle Mountain, Pennsylvania 552 



Cumberland-Keyser region, Maryland-West Virginia 553 



Introduction 



The object of this paper is to show that the Shawangunk grit and 

 conglomerate holds the position of the Medina sandstone and equivalent 

 formations which together throughout the Appalachian region occur at 

 the base of the Silurian system of strata. The Shawangunk-Medina for- 

 mations have overlying them, in unbroken sequence, as one gets about 

 30 miles from the main eastern outcrops, the Clinton shales. Then 



1 Manuscript received by the Secretary of the Geological Society August 10, 1916. 

 This paper was presented in abstract under the title "Shawangunk formation of 

 Medina age." 



(531) 



