XXVI Congreso Internacional de Americanistas

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During non-glacial times the mean monthly temperature at the pole
WQuld run aboye 28° F. and perhaps up to 60° F . Or 70° F. in the
summer. The polar region would have a cool, temperature humid climate.
Frost would be unknown except perhaps aboye the Arctic Circie
and on high mountains. In latitudes between 65" N. and 8cf N., especially
around the Arctic coast, there would be considerable areas with a
climate similar .to the 11editerrmnca.n. The winters,however, would
probably be cooler than the typical Mediterranean climate. Great stretches
of ternpem.ture fJra..ss lands would obtain in northern Eurasia and
North America. In the mountain areas along the western sides of the
continents aboye 50° N. latitude where the southwesterly winds would
have to rise to cross them, moisture would fall throughout the year.
Bere, also, the cool-temperature-humid climate would prevai] with deciduous
forests and in the highest altitudes, perhaps coniferous forests.
Between latitudes 35° N . and 50° N., the mountains along the west side
oi the continents would probably have a M,editerrrmean type of climate.
The proportion of arid lands would be increased. Great areas of desert
would prevail in the middle latitudes, especially throughout the interiors
of the continents. The regions is the ea'stern parts of the continents,
having a monsoon climate would be greatly increased in size. Be:ow
30Q N. latitude, especially in North America a wet-and-dry-low-latitude
climate would be the prevailing type.
Throughout North America, north of the Tropic, two prehistoric
culture horizons which have a vvorld-wide distribution, are known.
culture horizon is here defined as a broad stage in culture growth which
is identified through the processes used in the satisfaction of the fundamental
human needs. The earlier of the two horizons may be called
the Osteic and is characterized by the following processes: absence
of the agricultural process, absence of the true animal-domestication
process, absence of the true house-building process, absence of the ceramic
process, presence of the clothing process, weapons using on1y dire;:t
muscular force in hurling the projectile, and implements made from bone,
stone, shell, and wood, and certain special implements such as blades.
gravo's, and 'weapon points. The later of the two horizons may be called
the Ceramic. The following processes identify it: the ful! agricultural
process, domestication of animals, house-building process, the clothillg
process, self-ejecting weapons, the ceramic process, implements other than
ceramic made from bone, stone, shell, or wood, and certain special traits
such as the grooved-ax, polished celt, pipe, mortar and grinding stones.
The first great world horizon of which prehistory has concrete
evidence is the Lithic. It covers in time the epoch from about the beginning
of the Pleistocene to near the maximum of the W\irm-Wisconsin.
T'wo culture areas of the Lithic beco me c1ifferentiated c1uring very early
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