REVIEWS 273 



complex and dip gently westward beneath the Permian. They consist 

 of conglomerates, sandstones, and shales, and the conglomerates of 

 Parana are supposed to be the source of the diamonds of that state. 



Upper Carboniferous beds, containing marine fossils, are exposed in 

 the state of Para and also in Amazonas, north of the Amazon River. 

 They are shales, sandstones, and limestones, aggregating about 600 

 meters in thickness, but they contain no coal. In Bahia certain quartz- 

 ites, sandstones, and conglomerates which yield diamonds and carbo- 

 nados are doubtfully assigned to the Carboniferous. Branner discusses 

 in some detail the relation between these diamond-bearing strata of 

 Bahia and the diamond-bearing quartzites of Minas, and inclines to the 

 opinion that they are stratigraphically equivalent. The Carboniferous 

 rocks are not now known to contain other resources of economic signifi- 

 cance. 



The pre-Permian Paleozoic strata, which have been briefly described, 

 appear to be restricted to somewhat local occurrences and to represent a 

 moderate degree of sedimentation. It would seem as though Paleozoic 

 history in Brazil had been characterized by very gentle movements of 

 uplift and depression and correspondingly scanty erosion. The Permian, 

 on the contrary, is composed of two widespread series Lower and Upper 

 Permian, each of very considerable thickness. A belt of Permian rocks 

 from 100 to 500 miles wide, more or less, extends from near the Atlantic 

 Coast east of the Amazon, southward continuously through all the inter- 

 vening states, to Santa Catharina, a distance of 2,000 miles. East of it 

 lies an even broader belt and one of equal length, consisting of the 

 Brazilian complex and the infolded Paleozoic rocks. The latter con- 

 stitutes the Atlantic Coast ranges of Brazil and the eastern part of the 

 Brazilian plateau, while the Permian rocks form the surface of the plateau 

 farther west. The Permian rocks were apparently deposited in a great 

 geosyncline, which developed in the strip where they now occur along the 

 western base of a mountain range that furnished the materials for the 

 sandstones and shales. There is thus evidence that eastern Brazil was 

 mountainous in Permian time as it is today, and there is a certain paral- 

 lelism between the orogenic structure of eastern South America and that 

 of the eastern United States in Permian time. 



Branner summarizes the description of the Permian of Brazil, saying 

 that the rocks "seem to be mostly sandstones and shales, slightly dis- 

 turbed, but they include extensive beds of limestone — all of them cut 

 here and there by eruptive dikes. In Sao Paulo, Parana, and Santa 

 Catharina the Lower Permian contains glacial till with striated boulders. " 



