SULLEtlN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol. 18, pp.. 325-332 AUGUST 8, 1907 



STRATIGEAPHIC SUCCESSION IN THE EEGION NORTH- 

 EAST OF COOK INLET, ALASKA* 



BY SIDNEY PAIGE AND ADOLPH KNOPPf 



(Presented by title before the Society December 29, 1906) 



CONTENTS 



Page 



Introduction 325 



Region investigated 325 



Scope of the paper ■ 326 



Distribution of tlie terranes 326 



Middle Jurassic 326 



Lower Cretaceous > 330 



Tertiary 330 



Intrusive igneous rocks 331 



Summary 331 



Introduction 



The facts to be presented here were gathered during the summer of 

 1906, while undertaking a rapid geologic reconnaissance in the region 

 northeast of Cook inlet, Alaska. 



Eegion Investigated 



Cook inlet occu.pies a broad indentation on the western side of the gulf 

 of Alaska. The region explored is drained by two rivers — the first, the 

 Matanuska, emptying into Knik arm at the head of Cook inlet; the sec- 

 ond, Sushitna river, emptying into Cook inlet proper. Though portions 

 of the region have been visited at various times in the past by Eldridge,J 

 Mendenliall,§ and Martin, || much of the area is unknown. A notable 



* Received by the Secretary of the Society May 28, 1907. 



t Introduced by Alfred H. Brooks. 



+ G. H. Eldridge : Reconnaissance in Sushitna basin, Alaska, 1898. Twentieth Ann. 

 Rept. U. S. Geol. Survey, pt. vii. 



§ W. C. Mendenhall : Reconnaissance from Resurrection bay to the Tanana, Alaska, 

 1898. Twentieth Ann. Rept. U. S. Geol. Survey, pt. vii. 



II G. C. Martin : Reconnaissance of the Matanuska coal field, Alaska. Bull. no. 289, 

 U. S. Geol. Survey. 



XXVIII— Bull. Geol. Soc. Am., Vol. 18, 1906 325 



