VALLEY OF THE AMAZONS. 
155 
highly ferruginous sandy clay. During a stay 
of three months in Dio, whence I made many 
excursions into the neighboring country, I had 
opportunities of studying this deposit, both in 
the province of Rio de Janeiro and in the 
adjoining province of Minas Geraes. I found 
that it rested everywhere upon the undulating 
surfaces of the solid rocks in place, was almost 
entirely destitute of stratification, and con¬ 
tained a variety of pebbles and boulders. The 
pebbles were chiefly quartz, sometimes scat¬ 
tered indiscriminately throughout the deposit, 
sometimes lying in a seam between it and the 
rock below; while the boulders were either 
sunk in its mass or resting loose on the sur¬ 
face. At Tijuca, a few miles out of the city 
of Rio, among the picturesque hills lying to 
the southwest of it, these phenomena may 
be seen in great perfection. Near Bennett’s 
Hotel — a favorite resort, not only with the 
citizens of Rio but with all sojourners there 
wdio care to leave the town occasionally for its 
beautiful environs — may he seen a great num¬ 
ber of erratic boulders, having no connection 
whatever with the rock in place, and also a 
bluff of this superficial deposit studded with 
