STRATIGRAPHIC GEOLOGY 



215 



5. Ferruginous conglomerates and sandstones. 



4. Clay shales. 



3. Bituminous shales. 



2. Limestones. 



L Shales at the base. 



Unfortunately he does not tell where this bituminous shale was seen. 

 A bituminous shale is also reported by Dr. Lisboa in Maranhao. 



These notes and observations are all extremely interesting and sug- 

 gestive, and it is hoped that the evidences of glaciation and of the Per- 

 mian age of the beds in question may soon be examined and definitely 

 settled by a geologist thoroughly familiar with glacial phenomena. 



The evidences of the structural relations of the great limestone beds 

 of the upper Eio das Velhas to the Permian beds to the west of them are 

 not abundant, but they seem to be conclusive. Eschwege, whose obser- 



Sccie'gn icarass the newer deftosits in the^ 

 district of tkt leacL r^crve <f Jf6<xet£ 



^rci^/kycucke Artd- sillctoui shales 



Septan/ across th^ de^oiits ^rom^ Se-TTO 



Figure 2. — Ttco Sections from EscJiwege's Beitrdge zur Geliirgskunde Brasiliens 



The names in the original are here translated, and the greatly exaggerated vertical scale 

 is reduced to two-fifths of the original. 



vations and judgment must be accepted in all seriousness, gives two sec- 

 tions in which he shows the relative position of the rocks of the Eio das 

 Velhas and of those at the lead mines of Abaete west of Eio Sao Fran- 

 cisco. These two sections are here reproduced,^*^ and attention is directed 

 to his clear conviction that the limestones on both sides of the Sao Fran- 

 cisco underlie or form parts of the Permian beds. Whether the lime- 

 stones and his transition ("Uebergangsthonschiefer^') and other shales 

 really make part of the Permian is a question that can not be settled at 

 present. Eschwege's own views seem to be expressed in a footnote at page 

 488 of his Beitrage zur Gebirgskunde. He there says : 



"One must also not forget the wide-spread distribution of the transitional 

 areas of clay shales and limestones in the province of Minas Geraes, in the 



30 W. L. von Eschwege : Beitrage zur Gebirgskunde Braziliens. Berlin, 1832 (plate 

 no. 3). 



