188 
SOUTH AMERICAN GEOLOGY 
15,000 feet and have Indians bring in tropical fruit from a short 
day’s journey away, or pick alligator pears within artillery range 
of everlasting snow-fields. Is it not difficult to think of a pass, 
like the Zongo, in the Cordillera Real at 17,139 feet elevation. 
The anomalies, the physical ones at least, are largely the result of 
the mountain-mass overhanging the western coast and extending 
from Latitude 12° north to 56° south, across the equatorial and 
south temperate zones. 
The oldest land-areas of South America are supposed to be ap¬ 
proximately indicated by the present exposure of granitoid and 
gneissoid rocks of the Northern, or Guiana, highlands, lying be¬ 
tween the Amazon and Orinoco rivers, and the Eastern, or Bra¬ 
zilian, highlands, extending roughly from the mouth of the Ama¬ 
zon river to the mouth of the La Plata river. In a few places 
these crystallines are definitely dated as pre-Siluric, but the as¬ 
sumption that they represent an ancient land-area, or are pre- 
Cambrian in age, rests solely on analogy and on the unwarranted 
Wernerian tradition that rocks of this character are the oldest. The 
earliest known sedimentary rocks of western South America repre¬ 
sent very shallow-water deposits, and are known from only very 
limited areas, and the assertion seems justified that at the begin¬ 
ning of Palezoic times, throughout the greater part of Cambric 
time. South America was larger than it is at the present time. This 
is quite the opposite conception from the hypothesis of the two-fold 
origin of that continent as elaborated by Von Ihering. 
I may refer in passing to Wegener’s speculation which would 
regard South America as having drifted westward from a former 
union with Africa, an idea that is apparently regarded with favor 
by some of the young German geologists of the Argentine Survey. 
Ignoring the geophysical difficulties involved, which I am assured 
on high authority are insuperable, I can see no record of such a 
former union in anything that we know of the stratigraphy, struc¬ 
ture, faunas or floras. Moreover, it is opposed by the clear evi¬ 
dence of the west coast region having been a part of a land area 
with epicontinental seas to the east of it throughout all of the 
enormous extent of pre-Jurassic times. Between the juggling with 
the hypothetical Sal and Sima of the earth’s crust I much prefer 
the older hypotheses of land bridges and subsidence, if, indeed, 
such are really necessary to explain the observed facts. 
