148 N. Plant — The Brazilian Coal Fields. 



made in nearly every province in the Brazilian Empire and the 

 Eepublics of the Eiver Plate, that true Carboniferous rocks will ever 

 be found north of the province of Santa Catherina, unless it be in the 

 adjoining one of Parana (lat. 25° S.) 



The province of Eio Grande do Sul contains three distinct Coal- 

 basins, all of which I have examined, and ascertained, in some de- 

 gree, the extent and thickness of the Coal-strata. They are all con- 

 tained within the Hmits of lat. 30° and 32'^ S., long. 51° and 54° N., 

 and are separated from each other by rolling hills of granite, syenite, 

 mica-schist, and trachytic and basaltic rocks. The largest of these 

 deposits is, perhaps, the one occupying the valleys of the rivers 

 JaguarSo andCandiota between lat. 31° and 32°, long. 53° and 54°. 

 The sedimentary rocks forming this basin have an uniform inclina- 

 tion of 10° to 15° towards the south, and apparently rest upon the 

 mica-schist and sienitie rocks which enclose the valley of the river 

 Jaguarao and its confluents. The falling away of one side of a hill 

 in this basin, near its basset-edge, on the banks of the Candiota, laid 

 bare the strata to a considerable depth, disclosing five distinct beds 

 of bituminous coal ranging in thickness from 9 feet to 25 feet, giving 

 65 feet as the total thickness of the coal exposed. The accompany- 

 ing Section will show the order of superposition and thickness of the 

 different beds as they appear on the face of the escarpment. 



The Sandstone (No. 1) is evidently the uppermost rock, and forms 

 two ranges of hills, one dividing the waters of the JaguarSo from 

 those of the Candiota, and the other separating the tributaries of the 

 Candiota from those of the Jaguarao-chico. The thickness of this 

 bed varies considerably, being in some parts completely worn away, 

 and in othere attaining a depth of upwards of 200 feet. It contains 

 nodules of argillaceous peroxide of iron. Immediately below this 

 sandstone is found the first seam of coal-shale, 9 feet thick, which 

 can be traced wherever the superincumbent sandstone has been 

 denuded, for about 50 miles along a line running N.E.-S.W., and 

 for about 30 from ]S".W..-S.E. Below this is a bed of sandy-shale, 

 three feet in thickness, containing ochreous oxide of iron in the form 

 of septaria ; this overlies a bed ©f semi-bituminous coal (No. 4) 

 which rests upon a thin seam .of whitish clay, below which is an- 

 other bed of coal, separated by a thin bed of blue clay (No. 7) from 

 coal of a highly bituminous nature and possessing a thickness of 

 17 feet ; this again is divided by a parting of clay similar to No. 7, 

 from a bed of coal containing bands of Cannel-eoal, having a thick- 

 ness of 25 feet and very bituminous. 



Impressions of palgeozoic plants occur in this bed and in the iron- 

 stone shale (No. 11) upon which it rests. The thickness of this iron- 

 stone I have not been able to ascertain ; but it evidently rests upon 

 sandstone (No. 12), which is similar in every respect to the upper 

 bed of sandstone. This is the lowest bed shown in the escarpment ; 

 but from observations which I took in another part I found that this 

 sandstone (No. 12) rested upon beds of limestone, which in some 

 places appear to be separated by mica-schist. 



The Carboniferous rocks of this basia have apparently been but 



