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SOUTH AMERICAN GEOLOGY 
pattern both during, and at the close of, Jurassic time, e.g., con¬ 
tinental coal-bearing beds are common in the Western Andes of 
Peru between marine Jurassic beds and abundantly fossiliferous 
marine beds which have been referred to the Aptian stage of Early 
Cretacic age. These continental beds have been uniformly con¬ 
sidered as Wealden, or Neocomian, but there is little certainty 
about their true age. Those around Lima, Peru, appeared to me 
to represent the Portlandian stage of the Jurassic section and 
they were followed by marine Neocomian beds.® It would appear 
that Jurassic times were closed by a negative movement of the 
strand, and in places this resulted in emergent conditions, but 
there was certainly no great uplift or folding at this time. 
Because of conditions to which I will allude presently in con¬ 
nection with the Late Cretacic discussion there is great uncertainty 
regarding the succession of events during both the Early and the 
Late Cretacic periods. In the southern Chilean Andes the marine 
Early Cretacic section embraces beds that have been correlated 
with the standard stages from Tithonian to Aptian. Farther 
northward in the same region, the beds considered to be Aptian 
are continental in character. All horizons have also been reported 
from the great Mesozoic area of northern Peru, faunas that have 
been called Aptian and Albian being especially widespread. Per¬ 
haps all that can be definitely accepted is that between Latitude 16° 
and 30° South, marine sediments of an age not later than Mid- 
Jurassic, is succeeded by land in this central part of the Andean 
geosyncline, and the next recorded events are represented by strata 
that by some authors have been considered where Early Cretacic 
affinities (Aptian or Barremian), but which there is some evidence 
for considering them to be Later Cretacic in age. 
There are some continental deposits of Early Cretacic age in the 
Patagonian Andes and certain areas in the Brazilian Highlands 
have been tentatively assigned to this period. The Andean geo- 
syncline attained its greatest extent during Late Cretacic times, 
extending from Trinidad through Venezuela, Colombia, Ecuador, 
Peru, Bolivia and Chile, to Graham Land. Whether there was 
ever at one time a continuous sea throughout this extent is doubt¬ 
ful in view of the overwhelming Indo-Pacific character (accord- 
6 Geologia de Lima y sus Alrededores, Lima, 1907; and also Berry, E. W., Johns 
Hopkins Studies in Geology, No. 4, 1922. 
