796 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 



K 19 Marthas Vineyard and Nantucket (not mapped) 823 



K-L 11 Snake River basin, Oregon and Idaho , . . . 824 



L 10 Coast Bange of Oregon ; Cascade Range and Yakima Valley, Washington. . 825 



L 10-11 John Day Basin, Oregon, and Columbia Plateau 826 



L 12 Western Montana 831 



Lr-M 10 Olympic Peninsula, Washington 832 



Lr-M 11-12 Lake basins of western Montana 833 



M 12-13 Cypress Hills, southwestern Saskatchewan 834 



N 8-9 Graham Island, Queen Charlotte group (mapped as earlier Tertiary) 834 



N 10 Upper Peace and Phaser rivers, British Columbia 835 



N-O 4 Alaska Peninsula (not mapped) 835 



4 Bristol Bay 835 



O-P 9 Dease and upper Liard rivers, British Columbia 836 



P 6-7 Controller Bay region, Alaska. (See Chapter XVI, pp. 788-789.) 



Q 5-6 Yukon Valley (not mapped) 836 



Q 7 Upper Yukon (not mapped) 836 



Q6 ...Peel River (not mapped) 837 



Q9-10 Mackenzie Valley and Bear River (not mapped) 837 



R 5-6 Arctic coastal plain, Alaska 838 



R-U 16-22 Arctic Archipelago and western Greenland 838 



B-C 18. COLOMBIA. 



Karsten *^^ describes certain strata of Cretaceous 9-ge as occurring in the Cor- 

 dillera of Colombia (see Chapter XIV, pp. 581-582) and states that they are covered 

 unconformably by a micaceous white or yellow sandstone, of more or less coarse 

 grain, succeeded by quartzose (?) and variegated marls and by clay shales, which 

 include beds of lignite that alternate with the shales in thin layers and in beds up 

 to 3 meters in thickness. The latter group, which is distinguished by paucity of 

 fossUs, is not very thick in the higher regions, but it becomes thicker and more 

 important in the lower regions and in the valleys of Magdalena, Cauca, and Patia 

 it constitutes the surface to the exclusion of almost everything else. 



According to the region it is sometimes represented cliiefly by conglomerates, or again by 

 sands and clays; the latter, which are for the most part variegated in color and micaceous, 

 often contaia pebbles and pass into puddingstones. The conglomerates are formed of pebbles, 

 of the size of a fist or smaller, of a siliceous schist or of a quartzite which belongs to the rocks 

 which contain Foraminifera and which are united by sihceous cement. In some districts of 

 Magdalena this complex overlies the reddish-brown sandy marls which have been described 

 above and which contain flakes of mica; the latter should be studied in order to ascertain 

 whether it belongs to the Cretaceous or itself constitutes the lowest member of the Tertiary 

 series. The latter hypothesis appears to me most probable because the Tertiary conglomerates 

 rest directly upon this dense marl; the Cretaceous marls do not contain any mica. They are 

 firmer and more distinctly stratified and in their upper portion inclose thin layers of limestone. 



Karsten mentions the occurrence of petroleum in these strata, and continues : 



Limestones are rare in tliis Tertiary series. On the Upper Magdalena I have never observed 

 any fossUs. At Popayan I found a thin bed of argillaceous shale and hmestone resting upon 

 porphyry and containing shells of Tertiary moUusks (gastropods, Cardium, and RosteUaria 

 guadichaudi D'Orb.) very Hke those of the present. * * * 



With regard to the gigantic bones of extinct mammals, I may say that I saw them in 

 Colombia constantly in a red sandy marl which lies upon the Tertiary. In Ecuador one finds 

 them not only in the lower places but also upon the plateau and on the slopes of trachytic 

 volcanic cones, where they lie in part in a volcanic tuff that is to the general view very like 

 this marl. These remains are very widely distributed in the country. 



Karsten gives numerous localities at which he observed the remains of fossil 

 bones. 



