206 J. C. BRAXXER OUTLINES OF THE GEOLOGY OF BRAZIL 



Helmeeichen,^ 1846 



Gerbek, 1863 



(Geog. Vorkommen der Diamanten, (Nogoes ... da Provincia de Minas 

 1846) Geraes, 1863, pages 17-20) 



Graywacke 



Itacolumite 



Talcose and clay slate 



Slaty gneiss 



Granite-gneiss 



Transition 



Itacolumite 



Iron, talc, and steatite 



Itabirite 



Quartzite 



Granite-gneiss 



GoECEix, 1881 

 (Ann. Escola de Minas, volume I) 



Paleozoic limestone 



Francisco de P, Olh-eira, 1881 



(Ann. Escola de Minas, volume I, 

 page 53) 



Limestones, shales, and red sandstones 



Schists 



Iron (itabirites) 

 Quartzites (Caraga) 

 Schistose quartzite 



Granite-gneiss 



Itabirites 



Talcites and phyllites 



Quartzites 



Talcose rocks 



Talcites-mica schists 

 Granite-gneiss 



GoxzAGA DE Campos, 1910 



Harder axd Chamberlix, 1911 



(Iron Ore Resources of the World, Journal of Geology, volume XXIII, 

 volume II, page 816) pages 345-347) 



Limestones, age? 



Iron ore (itabirites) 



Sedimentaries 



Itacolumite quartzite 

 Piracicaba formation 

 Iron (mostly itabirite) 

 Batatal schists 

 Caraga quartzite 



Crystalline schists and granite 



Granite, gneiss, schists 



These tables lead to tlie conclusion that either the various writers on 

 the early Paleozoic rocks of Brazil are not speaking of the same places or 

 else they disagree about the subdivisions of the series. My own observa- 

 tions, both on the rocks themselves and on the writings of these geol- 

 ogists, lead me to believe that the rocks of this series vary from place to 



Helmreichen's section is at Grao Mogol and it probably does not belong here. 



