352 



E. C. HARDER AND R. T. CHAM BERLIN 



formation may be thin-bedded, while elsewhere masses many meters 

 in thickness and of great uniformity in texture may occur without 

 a trace of bedding. 



The distribution and structure of the quartzite are determined 

 by the general structure of the district (Fig. 3). The dips are 

 in general to the east or southeast at varying angles, except for 

 minor irregularities such as occur in the region between Ouro Preto 

 and Congonhas do Campo. Even where three or four parallel or 

 slightly intersecting belts of quartzite occur, this regularity of 



Caraca Quarlzlie 



Granile Gneh:> and 

 Cnc>laniT7e3c?ii5i 



Ilabira 



Baialal Sdihf n/i/h Serpemne Hraa'caba Jc^fsf 



Fig. 3. — East front of the Serra do Caraga. Section through Pitanguj' Hill. 

 Elevations given in feet. 



dip prevails. Such parallel belts of southeasterly dipping strata 

 are the results of thrust faulting and overturn folding, and their 

 regularity indicates the uniform nature of the deformation to 

 which the region has been subjected. 



The Carafa quartzite though varying in thickness extends 

 throughout the length of the sedimentary belt, being everywhere 

 well developed except in the region east and south of Bello Horizonte 

 where it appears to be absent, for the iron formation lies directly 

 on the basement complex. Along considerable portions of the 



