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sills and laccolites, that for purposes of classification, it was consi- 
dered best to include them as a part of the SA Bento Series, just 
as the geologists of South Africa have incltided corresponding erup- 
tive beds of the Upper Karroo or Stormberg series as the highest 
member of the same. 
This Sa Bento rock series of Brazil appears to be the exact equi- 
valent of the Stormberg series of Natal, Basuto Land, and of the Orange 
River and Cape Colonies, South Africa. 
As already stated this series of rocks covers a large portion of South 
Brazil, from the state of S& Paulo southward, the lower members 
cropping along the base and sides of the serra Geral, while the erupti- 
ves make its higher escarpments especially across Parana, Santa 
Catharina, and Rio Grande do Sul. In these states the Sao Bento series 
extends to and beyond the weslern boundaries of Brazil into the 
countries of Paraguay and Argentina, while in Sado Paulo they appear 
to end at the Rio Grande river on the north, where they rest upon 
the old crystallines, in the vicinity of Rifaina, and probably reach 
westward to and beyond Rio Parana. 
The different members of the series will now be described in 
detail. 
The Rio do Rasto Red Beds 
In the Palermo, Iraty and Estrada Nova shales occasional red, 
purple, or maroon colored strata occur, but they are always of slight 
thickness and may be in many cases due to secondary causes operating 
subsequent to deposition, but in passing above the Rocinha Limestone 
horizon, the rocks suddenly become dark red in color, and often varie- 
gated with whitish blotches 5 to30 centimeters or more in diameter, 
while at thesame time thick sandstones and conglomerates loosely 
consolidated (except where partially vitrified by trap dikes, sills and 
loccolites) make their appearance. 
These beds are well exposed on the bluffs and banks of the head- 
waters of rio do Rasto along the line of the Estrada Nova where it 
ascends the Serra Geral from Minas, Santa Catharina, and hence have 
been designated from that stream. 
