284 The Ohio Naturalist. [Vol. XI, No. 4, 



intimately united."'*^ (Compare this with the Chico-Tejon of 

 northern California.) On the western side of the border of Chili 

 and Peru, where the marine deposits of these fonnations predom- 

 inate, only a very small part of the rocks are fomied by limestones, 

 clay slates, or sandstones. These appear, however, to be "inter- 

 laid between stratified masses of porphyritic, melaphyric and 

 andesitic material, the entire thickness of which strata reaches 

 several thousand meters. "-^^ 



In the lower Amazon region the Cretaceous (?) rests uncon- 

 formably on the Carboniferous. The Cretaceous consists of yel- 

 low and white clays with red iron stone and some impure lime- 

 stone. The fauna of these beds shows a remarkabl}^ Tertiary 

 aspect. It consists, for the most part, of Gastropods, Pelecypods, 

 some Bryozoans, Corals and Echinoderms, as well as some prob- 

 able Reptilian remains. 



The plateau region of southern Para is mostly covered by clay 

 shales interstratified with red sandstones. The age of these 

 rocks is believed to be middle and older Cretaceous, and perhaps 

 in part even Triassic''^ or Pemiian. 



CENOZOIC. 



Tertiary. The Tertiary deposits of South America occur prin- 

 cipally along the coastal margin especially of Brazil, Argentine, 

 Chili and Peru. Also in the Amazon basin these beds cover a 

 large area,^- and again in southern Argentine the same is true. 



In eastern Brazil the Tertiary strata consist of slightly con- 

 solidated sands and clays which are undisturbed and overlie the 

 Cretaceotis unconfonnably.^^ Fossiliferous Tertiary beds (Upper 

 Miocene) occur in the vicinity of Coquimbo, Chili. ■^■* These 

 Chilian Tertiary shell beds, however, are found but sparingly in 

 Peru.-^^ The Tertiary beds of southern Patagonia vary from 

 seolian, swamp, and lacustrine deposits to sediments carrying a 

 marine fauna, and these are often interbedded with each other. 

 The maximum thickness is about 1500 feet.''" Tertiary lava flows 

 and intrusions of igneous rock are common throughout the Andes" 

 and arc not rare even in Patagonia. 



49. Steinmann, Gustav, loc. cit., p. 8.59. 



50. Steinmann, Gustav, loc. cit., p. 859. 



51. Katzer, Fricdrich, Grundziige der Geologie des iinteren Amazonas- 

 ^el)ietes, 1903, pp. 131-139. 



i>Z. 



Berghaus, Physikali.scher Atlas, No. 14. 



53. Hartt, C. F., Geol. and Phys. Geog. of Brazil, 1S70, p. 557. 



54. De Lapparent, A., Traitc de Geologie, Vol. Ill, 1906, p. 1621. 



55. Forbes, David, loc. cit., p. 9. 



56. Hatcher, J. B., Am. Jour. Sci., 4th Ser., Vol. XI, 1900, p. 99. 



57. Forbes, David, loc. cit., p. 12. 



