BRANNER: THE STONE REEFS OF BRAZIL. 83 



along the beach between Gamella and Guadalupe. The section and 

 geologic relations of these beds are shown in the sketch on p. 30. 





•3-40':: ■> 



<'-\ 



SJ 



j> of- flTi 



STONE %( Co f^AL 



Le 



•?7'54 (£-• o{~Rio de. Janeiro 





Fig. 51. The dotted line on the north side of the mouth of the river sliows the 

 position of the shore in 1875; the solid line to the west shows the shore in 1899. 



Pure white quartz sand 10-20' ^ 



Black soft sandstone 8' 



Yellow clay seam l"-2" 



White soft sandstone 7' 



Blue sandy clay at base ? 



1 These white quartz sands are well adapted to the manufacture of glass. The 

 bed in places is four metres thick, but for most of the distance from Gamella to 

 where the sands abut against the Guadalupe Tertiary hill, they have been blown 



