1 8 Wlmlfitum'n — Th< < Wt</ceox,s-2ertiary 



and Burckhardt 45 described several localities in this dis- 

 trict (Arroyo Pequenco, Arroyo Loncoche etc.) where 

 glauconitic marly limestones of a green color and gray 

 marls with typical fossils of the Roca-Beds have been 

 observed. Burckhardt divided the sediments in the syn- 

 cline Canada Colorada-Pircala into two parts and dis- 

 tinguished Senonian and Danian; but there can be no 

 doubt that this complex of sediments must be assigned 

 entirely to the Roca-Beds. Behrendsen 46 in his paleonto- 

 logic study of the material collected by Bodenbender, 

 compared these fossils with the so-called Cretaceous 

 fauna described by C. A. White 47 from Maria Farinha 

 near Pernambuco. Behrendsen tried to establish rela- 

 tionship between the Brazilian coast terrane and the 

 Paleocene of Mons, laying stress upon the appearance 

 of several Cerithium in Brazil. These, according to his 

 interpretation, have great similarity to certain Cerithium 

 of the European Paleocene. He further instanced three 

 Cerithium sp. found at Los Huincanes by Bodenbender, 

 but it seems probable that this classification may result 

 from a bad state of preservation. 



From a critical and summary examination of the vari- 

 ous sections published by Burckhardt and Bodenbender, 

 we get the following character and sequence for the Roca- 

 Beds of Canada Colorada : Upon reddish and gray sand- 

 stones with intercalations of variegated marls of the 

 Upper Cretaceous, there rests a complex of sediments 

 which in general consists of yellow limestones with marly 

 intercalations of a clear color carrying the molluscan 

 fauna; but there also occur limestones with bryozoa, 

 corals and remains of fish. This complex of sediments 

 has a thickness of about 240 feet and, towards the top, 

 goes over into slaty marls with banks of sandstone and 

 limestone. Gerth 48 who recently made more systematic 

 explorations in this region, also observed brackish and 

 lacustral deposits at the base of the Roca-Beds near to 

 Malargue. 



45 Profils geologiques transversaux de la Cordillere Argentino-Chilienne, 

 Anales del Museo de La Plata, Section Geologica y Mineralogiea II, pp. 

 53 etc., La Plata, 1900. 



48 Zur Geologie des Ostabhanges der Argentinischen Cordillere, Zeitsehr. 

 deutsch. Geol. Gesellseh., 43, 1891; 44, 1892. 



47 Contributes a Paleontologia do Brazil, Archivos do Museu Nacional 

 do Eio de Janeiro, 7, 1887. 



48 Die Pampinen Sierren Gentralargentiniens, Geologische Rundschau, 4, 

 pp. 577 etc., 1913. 



