RIVER-DHPOSIL OF THE AMAZON. 765 
Near the centre portion of the sec- 
tion, bed 2 contains layers of pinkish 
sand, and is there exceedingly false- 
bedded. At section B bed 4 is seen 
to have changed into a false-bedded 
yellow sand and clay; at C to a 
greyish-white clay; at D to a grey 
clay ; at E to a grey arenaceous clay, 
marked with curved layers of the 
same material; at F to red, white, 
and grey clay in regular layers; and 
at G to its original composition and 
colour. Bed 6 changes at B to a 
white arenaceous clay; at D to a 
white clay, striped with red layers ; 
and at F to a white sand again. 
In this portion of the cliff the base 
of the beds was not seen, but to the 
eastward it was shown by an expo- 
sure of ferruginous sandstone. 
At Obidos, however, the base of the 
deposit is clearly exposed when the 
river is comparatively low, and is 
composed of pinkish sand. This rests 
upon the soft, variegated, red and 
white friable sandstone before referred 
to, which has a slight dip in a 
westerly direction. 
_ Cavaraucu cliffs give a section in 
one place 190 feet in height ; but as 
they are the front of land rising to 
heights of over 200 feet above the 
river, I am inclined to believe that 
they are, in part at least, sections of 
the friable-sandstone deposit. With 
the exception of some 10 ft. of red and 
yellowish clay on the top, the whole 
of the section was formed of grey, 
pink, and lilac layers of arenaceous 
clay, having in it patches of red colo- 
ration, as well as thin layers of pure 
white clay. The red clay from the top having been washed down 
the face of the cliff for some distance, gave it the appearance of being 
composed of red clay in all its upper portion. 
The cliffs along the borders of the Solimées are not so high as those 
upon the Lower Amazon. The first of these, occurring at Mana- 
caparu, is 60 feet in height. It is composed of reddish and yellow 
loam, resting on sand beds in one part. Both at the base and near 
the top iron-impregnated layers of clay, forming a honeycombed 
yariety of ferruginous rock, occur ; while in another place white clay 
beds are seen resting on bright red beds. 
Q.J.G.8. No. 140. 38 
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