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BRANNER: THE STONE REEFS OF BRAZIL. 147 
Inasmuch as the “ drift clays” mentioned by Hartt were regarded by 
him as of glacial origin, he seems to have thought it necessarily a land 
deposit, and that the coast was submerged since the glacial epoch. 
It has been shown elsewhere? that there is no satisfactory evidence 
of glaciation in Brazil. 
The * drift" Hartt mentions is probably a part of the water-worn 
material covering the region lifted from beneath the sea at the close of 
the Tertiary. It indicates a depression since that emergence. 
Hartt also recognized the evidence of the Alagóas lakes, for he says 
(р. 422): “These lakes of Alagóas, as well as Juparana, are very deep, 
and their basins must have been excavated at a time when the land 
stood at a greater height than at present.” 
Darwin notes the existence of fresh-water Tertiary beds at the head 
of the Bay of Bahia “now washed by the sea and encrusted with Balini ; 
this appears to indicate a small amount of subsidence subsequent to its 
deposition.” I suppose the idea is that the fresh-water deposits were 
laid down above tide-level. This may or may not have been the case. 
The bottoms of the great fresh-water lakes of North America are far 
below sea-level, 
On the island of Fernando de Noronha, two hundred miles northeast 
of Cape St. Roque, wind-bedded sandstone of recent geologic origin 
extends beneath the water at high tide. 
There can be no doubt about the wind-bedding of these rocks, for in 
some places the false-bedding dips strongly toward the hills against 
which they are deposited.? The wind-bedding could only be produced 
above water. This shows that there has been a depression of the land 
since the sands were deposited. 
Elisée Reclus in speaking of the encroachment of the sea about the 
mouth of the Amazon says that it seems to be due to a general de- 
pression of the coast.? As evidence of the recent depression of the 
region about the mouth of the Amazon, Coudreau mentions a large 
number of enormous stumps in the bed of the little Mapa river on the 
coast (2° N. lat.).4 
1 J.C. Branner. The supposed glaciation of Brazil. Journ. Geol., 1898, I., p. 753-772. 
2 J.C. Branner. Geology of Fernando de Noronha. Amer. Journ. Sci., 1889, 
XXXVIL, р. 160-161. 
J. C. Branner. The wolian sandstones of Fernando de Noronha. Amer. Journ, 
Sci., 1890, XXX., р. 247-257. 
з Élisée Reclus. Nouvelle géographie universelle. Tome XIX, Amérique du 
Sud, р. 146. Paris, 1894. 
t Henri A. Coudreau. Voyage à travers les Guyanes et l'Amazonie, р. 
10-11. Paris, 1887. 
