SEDIMENTARY BELT OF THE COAST OF BRAZIL 233 
diabase. Similar rocks characterize a large region in southern Brazil, 
where they are presumed to be of Triassic age. As no signs of 
eruptive activity have been detected in the sedimentary belt of the 
mainland, it is possible that the Abrolhos outcrop may prove to be 
somewhat older than those above discussed. However this may be, 
it must be regarded as a remnant of the same costal sedimentary 
belt representing a considerable, perhaps the major, portion of it 
that has disappeared on the submerged border of the continent. 
Branner (12) has described several outcrops of oil-shale on 
the coast of the state of Alagoas, in some of which he found plant 
remains, and in one a fossil fish identified with a species occurring at 
Bahia. There can be little doubt that these various deposits are to be 
correlated with those containing fossil plants and fishes at Bahia, 
Marahu, and Ilheos. Vague information relating to the northeast 
section of the coast between Pernambuco and the mouth of the 
Amazonas indicates that at various points similar deposits occur 
along it. 
The information at present available regarding the unmetamor- 
phosed geological formations of the coast of Brazil may be summar- 
ized as follows: 
t. With the exception of comparatively rare and short sections, 
the whole coast from Cape Frio northward is formed, in its highland 
portions, by Mesozoic and Tertiary sediments, with which are associ- 
ated eruptives of basic character at the Abrolhos islands. 
2. In the southern section of the coast, from Cape Frio to the 
eastern shoulder of the continent at Cape St. Roque, these sedimentary 
rocks form only a narrow belt and abut against, or overlap, the mar- 
gin of a shield-shaped mass of Archean( ?) metamorphic and crystal- 
line rocks, fringed in places (rarely along the Atlantic border region) 
by sharply inclined early Paleozoic strata. In the northern section, 
from Cape St. Roque northward to the mouth of the Amazonas, 
they in places extend far inland, occupying baylike indentations in 
the margin of the Archean (?) shield, or abut against older (?) 
Mesozoic (Ceard in the semicircle of sedimentary table-lands— 
Serras de Apody, Araripe, and Ibiapaba—that surround a minor 
shield in the central part of that state), or late Paleozoic (Piauhy, 
Maranhao, Parad, and northern Goyaz) strata that form the high 
