Periodicos estrangeiros 

GEOLOGIA 
Proceedings of the American Philosophical Society ( held 
at Philadelphia for promoting useful knowledge ). — Vol, 
LIL. 193: 
Olaf Bitt Jenkins: Geology of the Region about 
“Natal. Rio Grande do Norte, Brasil, p. 431-467 ( Plates XV 
XXII). «The State of Rio Grande do Norte is one of the 
smallest in Brazil; it has an area of 57.485 square kilo- 
meters, and lies wholly within the tropies. The climate, to- 
pography and geology of this state may be taken as a type 
of the geology of the northeastern coast of Brazil... «J. 
C. Brauner» p. 432. . . « The most important results from 
this work are as follows: 
1. The determination of an unco formity between the 
particolored sandstone and clay series and the underlying 
limestones. 
2. The finding of fossils in the limestones. 
3. The determination that the limestones were laid 
down as estuarine deposits, thus indicating a sunken coast 
at that time such as exists now. 
4. The proof that the coast has sunken recently, and 
the commercial effect that this condition has had upon the 
country in affording fine harbors, and in making good agri- 
cultural land by the deposition of silt in the rivers forming 
sterile valleys. 
5. The effect wind blown sand upon the country in 
damning streams and thus forming fresh-water lakes. 
6. The large supply of good water in the region of 
the sedimentaries in comparison to the lack of water in the 
dry interior ». 
l. s. c. vol. LV, pp. 1-20 ( Plates I-IV). 
Ralph H. Soper: The Geology of Parahyba and Rio 
Grance do Norte, Brazil. 
« The data for the following paper was gathered in a 
series of three expeditions made into the states of Parahyba 
and Rio Grande do Norte; (p. 1). The states of Parahyba 
and Rio Grande do Norte form three general topographic di- 
visions. The first is a zone of low coastal sediments of 
Cretaceous and Tertiary age. The second is a great plateau 
which rises fron? the western edge of the coastal plain and 
