TRIASSIC PERIOD 



577 



layas, southern Siberia, and northern Tibet. He also reports that a little 

 later the Tirolites fauna appears, having a decided Mediterranean aspect, 

 but enduring for a short time, and that the Lower Triassic closes with the 

 Columbites biota of few species, having boreal or northern Siberian charac- 

 teristics. 



Table of Western Triassic Formations. After Smith, 1907 







California 



Nevada 



Idaho 



British Columbia 







Pseudomonotis subcircularis 

 slates 



Pseudomonotis 

 slates 





Pseudomonotis 

 slates 





a 

 o 



s 



<n 



03 



o 



Spiriferina beds 



Star Peak li. 



No characteristic 



fossils 









Juvavites beds 





m 

 03 







Tropites subbulatus beds 



Dawsonites 

 beds 



a. 



Halobia superba beds 







Slates with Halobia cf. 

 rugosa 



Daonella 

 beds 





C 



o 

 £ 



Slates and tuffs without 

 determinable fossils 







— s 

 •So £■ 



* % 5 



a c ee 



o s *- 



Gymnites 

 beds 





o 



m 

 .2 



Clay and siliceous slates 

 with Anolcites cf. it;/n£- 

 neyi and Ceratites cf. 



Daonella du- 



bia, Ceratites 



trinodosus 



beds 





H 





c 

 <s 



CO 



< 



Columbites 

 beds 





■5 



0) 



be 



a 



cS 



O 

 >> 



c 



* 



Q 



Black limestones with Pa- 

 rapopanoceras, Xenodis- 

 cu&, Arochordiceras, and 

 Hungarites 





£ 



Tirolites 

 beds 







Calcareous slates without 

 fossils 





"a. 

 tr. 



Meekoceras 

 beds 





C 



O 



Meekoceras beds of Inyo 

 county, Meekoceras gra- 

 cilitatis, Usswia, Pseudo- 

 ueceras, Inyoites, Owen- 

 ites, Nannites 









Triassic elevation still continued in the Kocky Mountain area, and all 

 along the Pacific region there is constant proof of much volcanic activity, 

 for according to Dawson 222 the Nicola and Vancouver series in British 

 Columbia consists largely of volcanics and attains a thickness of 13,500 

 feet. Toward the close of the Lower Triassic the sea was withdrawn from 



222 Dawson : Annual Report of the Geological Survey of Canada, vol. 7, 1896. Bull, of 

 the Geological Society of America, vol. 12, 1901, pp. 57-92. 



