BRANNER: THE STONE REEFS OF BRAZIL. 21 
to 15° N. 45° W. beneath the hill It overlies the strongly bedded 
conglomerates and sandstones exposed on the right. The dip is not 
constant, however, for one hundred and fifty metres down the shore the 
dip is more nearly west. The exposure of the bituminous shales shows 
them to be nearly two metres thick, but it is possible that they have a 
thickness of three or four metres. 
Now the lower or left (south) end of this shale is a fossiliferous peaty 
or bituminous bed with limy streaks and patches in it, while the upper 
or right end merges into a mass of mushy nondescript purple and brown 
sandy clays. Further, the discoloration has progressed more rapidly in 
the sandstones beneath the shales than in the shales, so that the former 
are already mottled and stained to a depth of six metres or more below 
Nm 
Sou MU 
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4] 
Fie. 3. Exposure on the beach at Barreira do Boqueirão. 
the base of the shales. It should be added that the conglomerates of 
this section contain water-worn granite boulders as large as a man's 
head, 
At the City of Maragogy, State of Alagóas, only fourteen kilometres 
north of the Barreira do Boqueirão, a section is exposed at the base of 
the hill in the rear of the church. Here the bottom stratum, perhaps 
not more than five or six metres above tide, is false bedded and mot- 
tled so that it strongly resembles the bottom bed at the Barreira do 
Boqueiräo. 
At Riacho Doce (8. lat. 9° 36’), the shales and sandstones are exposed 
from the mouth of the stream southward nearly to Garça Torta. As in 
many other places, they are cut off by the waves so that they are well 
exposed only at low tide. They are much bent and faulted at this 
