726 CHARLES SCHUCHERT 



of young Cretacic marine sediments, and the same condition prevails 

 in the southern states of Brazil, as Parahyba, Pernambuco, Alagoas, 

 and Sergipe. A great marine Cenomanian Cretacic transgression, 

 as given in several geological works, is not true of the interior of 

 Brazil nor of the Amazon valley. This development is as follows : 



With the beginning of the Mesozoic, to the old Guiana-east- 

 Amazonian land, there was added the young Paleozoic deposits, and 

 the resulting Guiana-Brazilian continent formed the eastern shore of 

 the Triassic sea whose deposits are found in the Andes. The southern 

 Pacific continent of this time remained as it was during older Paleozoic 

 time. At the close of the Jurassic the sea extended and spread 

 toward the east. 



The first indications of the Atlantic and its transgression upon the 

 land of northern South America took place in Upper Jurassic time. 



The Guiana- Brazilian continent, which extends southward across 

 the Amazon region, was maintained, although decreased in size along 

 the east, and dissolved into islands toward the southeast. Similarly, 

 there still existed the old land connections between South Africa and 

 southern South America on the one side, and on the other with Aus- 

 tralia and New Zealand. 



Between these two continents the inclosed sea of about Middle 

 Cretacic time began to enlarge and covered portions of the state of 

 Sergipe, where Cretacic deposits rich in ammonites discordantly rest 

 upon the Paleozoic. Dr. Charles A. White referred these beds to 

 the Upper Cretacic; F. Kossmat, to the Cenomanian; Douville, to 

 the Upper Albian (Gault). In all probability they belong to the 

 transition zone between the Lower and Upper Chalk, and indicate 

 a restricted Cenomanian marine extension over this part of Brazil. 



Incomparably larger, however, was the transgression of the young- 

 est Chalk (Senonian, in part Danian), which also touched the lower 

 Amazon region. This transgression was from the south, attaining 

 first Sergipe, later Pernambuco, and finally also Para. The main 

 part of the Sergipe Chalk belongs at the base of the Upper Cretacic, 

 but some faunal elements indicate the presence of higher zones 

 (Turonian, even Senonian). In Pernambuco the Senonian prevails, 

 and in Para, only Senonian, with some transition to the Eocenic. 



During the continuance of the east-Brazilian Cretacic trans- 



