8 INSTITUTE OF SOCIAL ANTHROPOLOGY—PUBLICATION NO. 5 
The largest lake in the area under consideration 
is Lake Junin, some 25 miles long by 8 to 10 miles 
wide, situated to the south of the town of Cerro 
de Pasco at an elevation of approximately 12,200 
feet (pl. 2, 6). Other small lakes, fed by the 
melting snows, lie in the punas to the west and 
north of Lake Junin. To the south, in Huanca- 
velica Department, the two small lakes Choclo- 
cocha and Orcococha are situated on the dreary 
punas at an altitude of some 14,000 feet. The 
only lake worthy of mention in the lower regions 
included in the present study is the lagoon of Paca, 
which les in a pleasant little tributary valley 
some 6 miles to the north of the town of Jauja 
(pl. 14, d). 
CLIMATE 
There are but two seasons in the Central High- 
lands, a dry winter from April to November and 
a rainy summer from October to May. Winter 
days are clear and often cloudless, and the heat at 
midday contrasts sharply with the cold nights, 
when subfreezing temperatures are frequently ex- 
perienced. The coldest weather usually comes 
during the months of June and July. During this 
season the climate is very dry, and in the cultivated 
zones the slightest breeze raises clouds of dust 
from the plowed fields. The summers are usually 
characterized by heavy rain in the form of thun- 
derstorms and not infrequent hail, but there may 
be steady downpours for days at a time. Al- 
though the nights are warmer than those of the 
winter season, the days are frequently cold and 
unpleasant owing to the overcast skies. Com- 
paratively little snow falls below 14,000 feet, and 
the line of perpetual snow varies from 15,000 to 
17,000 feet (Dunn, 1925, p. 17). 
As many writers have pointed out, climate in 
the Andean area is almost entirely dependent upon 
elevation above sea level, although there may be 
local variations due to special topographical in- 
fluences. In general, the Highland valleys tend 
to have temperate climates, and in these there are 
good land, abundant water, and a climate favora- 
ble to agricultural activities. The punas, on the 
other hand, tend to be chilly and disagreeable 
throughout the year and are unsuitable for farm- 
ing because of the altitude and the cold; between 
these two extremes there is an extensive range of 
local climates. Indeed Pareja Paz Soldén (1943, 
p. 55) distinguishes four climatic zones (yunga, 
hot; quechua, temperate; puna, cold; and glacial 
or polar) which correspond closely to those, 
mentioned earlier, based on altitude. 
Although few statistics are available, there 
appears to be considerable variation in rainfall 
throughout the region under discussion. In 
general the eastern cordillera receives more rain, 
the western chain less. Morococha, situated in 
the puna zone on a spur of the Central Railway 
at an altitude of 14,000 feet, received a mean 
annual rainfall of 40 inches from 1906 to 1911 
(Dunn, W. E., 1925, p. 17). Near Huancayo 
in the Jauja Valley, the mean annual rainfall 
between 1923 and 1945 was 29 inches.’ It is 
unfortunate that similar figures for Ayacucho 
and Huancavelica Departments are not available. 
THE JAUJA VALLEY 
Roughly elliptical in shape, the Jauja Valley is 
approximately 35 miles long by some 12 miles 
wide. On either side it is flanked by rolling, 
eroded red hills, barren during the dry season, 
but pleasantly green during the rainy months. 
Here and there, over the hills to the east, rise 
occasional snow-capped peaks of the Cordillera 
Central. From the hills on each side, the valley 
floor descends in two broad, flat terraces to the 
present flood plain of the Mantaro River. It has 
been stated that the Jauja Valley is of lacustrine 
origin, and that the lagoon of Paca, to the north 
of the the town of Jauja, is a vestige of this former 
highland lake (Pareja Paz Soldén, 1943, p. 45). 
The Jauja Valley, which lies within what has 
been designated as the Sierra zone, is one of the 
most productive regions of the Central High- 
lands. The valley floor is under intensive cul- 
tivation, and there are large fields of barley, 
wheat, maize, potatoes, and alfalfa, and lesser 
plots of garden vegetables (pl. 14, 6). Cattle 
and sheep graze in the fields which lie fallow, 
and pigs root along the river banks. Horses 
and trains of burros, laden with farm produce 
and articles of home manufacture and driven by 
the enterprising natives, pass up and down the 
roads, to and from the numerous markets. Few 
llamas, with the exception of those which have 
come down from the punas, loaded with upland 
products, are in evidence in this region. The 
valley roads are lined with hedges of maguey 
and cacti, and tall clumps of Scotch broom grow 
along the river. Extensive stands of eucalyptus 
5 Information supplied by Mr. Paul G. Ledig, Observer-in-Charge of the 
Carnegie Institution magnetic observatory at Huancayo, altitude 11,000 feet. 
