branner: the stone reefs of brazil. 19 



than real, aud as the apparent bedding is associated with the coloring, 

 these features of the series may be treated together. Seen from several 

 miles at sea, the horizontality of the colors sometimes gives the rocks the 

 appearance of having horizontal beds, when in reality the colors cut 

 across the beds. At the colored cliffs just south of Rio Camaragibe in 

 the State of Alagoas this can be seen fairly well. The bluflFs at that 

 place are from seventy-five to one hundred metres high and the upper 

 part is all highly colored. Plate 11 is taken at this locality from a 

 platform of unaltered rocks shown in tlie foreground that is covered at 

 high tide, when the water reaches the face of the steep bluff. These 

 beds dip gently toward the right at an angle of from 5° to 8°. Atten- 

 tion is directed to a fairly well-defined light-colored band that runs 

 along the top of the steeper part of the bank. This band is the lower 

 limit of the colored portion of the rocks in these hills, and it can be 

 seen even in the photograph that the line of discoloration is horizontal, 

 while the beds have a gentle but decided dip. Above the line of dis- 

 coloration the rocks are colored and mottled soft clays aud sands, mixed 

 in all sorts of proportions, but whose bedding is more or less difficult 

 to trace. These are the rocks we have been in the habit of callino- 

 Tertiary. Below the horizontal band they have their bedding perfectly 

 defined, and vary from coarse sandstones to fine compact shales, in color 

 mostly grays of various shades, and dark brown to almost black. They 

 have limy streaks in them here and there, and the shales often have 

 a lumpy or concretionary appearance. The unaff'ected parts of these 

 beds are only from five to seven metres above tide, and the top of the 

 unweathered portion retains this elevation regardless of the dip of 

 the beds. 



The line separating the colored and the nncolored portions is not a 

 clean-cut one. The unaffected beds can be traced upward into and 

 across this line ; but the change is a very gradual one — it is only when 

 one stands away from the exposure and tries to trace out the individual 

 strata with the eye that he cannot do it. 



Plate 12 is another view that shows well the bedding of these Cre- 

 taceous shales and sandstones at the same place. The lower portion 

 of the bluff is washed by the sea at high tide, and up to a height of six 

 metres these beds are dark and light grays. The top of the bluff where 

 the plants grow is decomposed and highly colored. The rocks dip 

 away from the observer at an angle of 14°, and just round the corner 

 shown on the left the line of discoloration cuts the tops of the series 

 along an approximately horizontal plane. 



