78 C. B. BROWN ON THE TERTIARY DEPOSITS ON THE 
Another section, nearer the town, gives the following :— 
‘ : Reddish arenaceous loam. 
aa ‘ 9 : 
River-deposit. 29 feet. LW hite sand, with pebbles. 
: 2 Bluish-grey clays. 
TRSRBENT gosoce Bo x Geer seoaaasoud clay. 
It is difficult to determine whether the Tertiary beds ever extended 
eastward down the Amazon beyond St. Paulo; for, with the excep- 
tion of a blue shaly clay weathering of a brownish-green colour, 
lying at the base of the river-deposits, and only exposed when the 
waters are low, no beds are seen in any way resembling them. 
This shaly clay, which is seen in most sections on the Solimées as 
far down as the mouth of the Purus, is unconformable to the base 
of the overlying beds, and contains well-preserved leaves, which are 
of very doubtful value in determining its age. Beds of friable 
sandstone occupy its place below the river-deposit at Obidos and 
Montealegre ; but not sufficient data have, as yet, been collected to 
show whether they are of Tertiary age or otherwise. 
In ascending the river from St. Paulo, the next cliff-sections are 
at St. Cruz, and again at Caldeirao, on the north side of the Solimées 
some 84 miles on; but they do not expose any Tertiary beds. 
Some 20 miles below the mouth of the Javary, on the south bank, 
the low cliffs there seen are composed of Tertiary beds, which, 
further on, at a place called Rebeirés, are fossiliferous. The section 
there exposed is as follows :— 
: P 4 Red clay. 
Seiya ATEEE | Mottled grey and red clay. 
1 foot. White sand and gravel. 
5 feet. Light greenish clay. 
2 ,, Greenish-blue clay, with layers of shells, and having 
a layer in it of hard reddish clay full of shells. 
Tertiary ...... i 
River. 
The fossils in the greenish-blue clay are of the same kinds as 
those found in the sections on the Javary, described below, while 
the hard reddish clay contains a great abundance of small univalves. 
The Tertiary beds first met with on the Javary are at the 
Barreiras (cliffs) of Santa Anna, where, at the foot of their sloping 
front of reddish and grey clays (a short distance below the landing- 
place), greenish clays containing brown concretionary nodules are 
seen. At the time of my visit the level of the Javary stood at 38 
feet below its high-water mark of floods, and consequently was 
some 20 feet above its lowest level in the dry season. Thus it will 
be seen that a considerable portion of each cliff-section was hidden 
from view. 
At Barreiras Braga the first bed of lignite, which is 2 feet 6 
inches in thickness, is seen with its base at the water-level, dipping 
south at an angle of 3°. Lying upon it is a thick layer of greenish- 
grey arenaceous clay, containing shells like those at Canama, a 
section to be described further on. There is this difference, how- 
ever, that the bivalves predominate in number over the univalves in 
this section, whilst at Canama they are more evenly balanced. 
