52 bulletin: museum of compaeative zoology. 



V. PERIVIIAX GLACIAL DEPOSITS OF SOUTH BRAZIL. 



"In the next great section of the earth's crust, the Permian period, we have 

 an almost world-wide extension of glacial waste * * * Even in the Southern 

 Hemisphere we have what seems to be conclusive proof that the glaciers 

 during this age operated in regions nearer the equator than they did during 

 the last glacial period." 



Shaler in Shaler and Davis. Glaciers, Boston: 1881, p. 96. 



"Evidence is slowly accumulating which serves to show that glacial periods 

 of greater or less importance have been of frequent occurrence at all stages in 

 the history of the earth of which we have a distinct record." 



N- S. Shaler. Outlines of the Earth's History, New York: 



1899, p. 247. 



The foregoing statenaents concerning the boulder-bearing Permian 

 beds of south Brazil show the state of the inquiry concerning the 

 origin of these deposits as late as 1908. Dr. Derby, Professor Branner, 

 and Dr. I. C. White were essentially in agreement in regarding as 

 highly probable the glacial origin of the boulders, but striated rock 

 surfaces either of the bed rock or as transported erratics were wanting. 



The boulder-bearing beds of the Permian in south Brazil are far 

 from presenting a persistent parallelism of strata from point to point 

 along their outcrop. In the state of Sao Paulo the typical tillite is 

 seemingly wanting except near the southern border, the evidence of 

 ice-action being limited largely to argillaceous sandstones carrying 

 occasional stones and boulders. The typical tillites crop out on the 

 northern border of the state of Parana and are exposed at what appears 

 to be more than one horizon as far south as Santa Catharina. In 

 eastern Santa Catharina in the section along the Rio Tuberao there are 

 no surface exposures of tillite, but waterworn conglomerates occur 

 at a low horizon in the section apparently representing as at Ponta 

 Grossa in Parana the glacial episode. 



The following account of the sections studied by myself begins with 

 the beds on the north in the state of Sao Paulo, and includes the 

 following sections : — 



a. The section from Itaicy to Piracicaba in Sao Paulo. 



b. The section on the Rio Jaguaricatu in northern Parana. 



c. The section from Ponta Grossa to Conchas, Parana. 



d. Exposures between Ponta Grossa and Serrinha, Paranii. 



e. The section from Serrinha via Lapa to Rio Negro, Parana. 



f. The Orleans-Minas section in the Tuberao Valley, Sta. Catharina. 



