708 INDEX TO THE STRATIGEAPHY OF NORTH MffiRICA. 



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N 4 Chichagof Cove, Alaska Peninsula 782 



N 4, 4-5 Alaska Peninsula (mapped in pait) 783 



5 Kodiak Island and Katmai Bay 784 



8 Southeastern Alaska (not mapped) 784 



O 10 Finlay and Omenica rivers, British Columbia '. . . . 785 



0-P 5 Kenai Peninsula 785 



P 3 Nunivak Island and Yukon Delta 7S7 



P 5 Cook Inlet near Tyonek 787 



P 6 Matanuska Valley 788 



P 6-7 Controller Bay to Cape Yakataga (mapped with later Tertiary) ; Mount "Wrangell 



district, Alaska (not mapped) .■ 788 



P-Q 5-6 Foothills of the Alaska Range (not mapped) 790 



Q 3 Seward Peninsula (not mapped) 791 



Q 3-4 Norton Sound, Alaska (not mapped) 791 



Q 4-5 Kobuk River , 791 



Q 5-6 Yukon Valley (not mapped) 792 



Q 7 Upper Yukon 792 



R 5-6 Arctic coastal plain (mapped with later Tertiary) 792 



R 26-27 Northeast coast of Greenland (not mapped) 793 



B 18. COLOMBIA. 



A formation which has been assigned with doubt to the Cretaceous or Tertiary 

 is described by Hettner ^^''^ as the Guaduas formation of the Cordillera of Bogota. 

 This was recognized by Sievers in the Cordillera de Merida in Venezuela and there 

 entitled the Cerro de Oro series. It consists of bright-colored, especially red, 

 yellow, or violet clays that contain particles of brown iron ore and interbedded 

 layers of coarse sandstone which is mostly red or dirty white and which in. places 

 becomes conglomeratic. The lower portion of this formation or the upper part of 

 the underlying Guadalupe (Upper Cretaceous) belongs to the coal-bearing strata 

 of Colombia.- No other fossils than imperfect remains of plants have been found 

 with the coal. Karsten was of the opinion that this formation was unconformable 

 upon the Guadalupe and therefore considered it to be Tertiary. Hettner, however, 

 regards the unconformity as apparent rather than real, and as he could not find 

 any sharp boundary between the two divisions, he doubted the Tertiary age of the 

 Guaduas formation, thinking it more likely Cretaceous. 



B-C 19. VENEZUELA. 



Sievers,^"" in describing the Cordillera de Merida, places provisionally in the 

 early Tertiary a division which he calls the Cerro de Oro terrane. He says: 



In Tachira, as well as elsewhere in various places in tlie Cordillera, massive deposits of very 

 varied constitution lie above the limestone of Albien age. In various places one may observe 

 coal beds occurring between shaly calcareous and sandy formations, and in two places petroleum 

 occurs in these deposits. It is probable that the thickness varies from place to place and that 

 it may often be impossible to establish a particular sequence of strata, especially as the forma- 

 tion has undergone great tectonic disturbance. However, I had the good fortune to discover 

 at least in one place a thickness of 800 meters in which the relations of this formation were 

 clearly presented. 



The section as measured by Sievers and given in great detail shows an alter- 

 nation of thin sandstone, shale, and carbonaceous layers and is compared with the 

 Caroni series of Wall in the Island of Trinidad. Sulphur occurs as a characteristic 

 constituent of many of the sandstones. 



