NEW WORLD PALEO-INDIAN—ROBERTS 405 
and made it more liable to breakage, hence would not have been done 
without good reason. 
Animal bones with which Folsom implements frequently are asso- 
ciated are those from bison, the mammoth, large American camel, 
antelope, extinct and living forms of the musk ox, giant sloth, and 
the native horse. The mammoth, sloth, camel, horse, antelope, and 
kinds of bison represented are no longer in North America, and the 
living type of musk ox is now far north of the area where the archeo- 
logical specimens are found. Bones from animals still present in 
various parts of the country also occur in Folsom sites. In this group 
are rabbit, fox, wolf, deer, and pronghorn, species that have changed 
so little over a long period of time that they have no bearing on the 
problem of relative age. Some of the sites also contain invertebrate 
fossils as well as mammal remains. Included in this material are 
species that either are extinct or no longer live in the districts where 
such assemblages occur. Wood, in the form of charcoal, found in 
hearths and accompanying the bones has a similar status. There is 
good indication of a climatic change and the lapse of an appreciable 
length of time in these mammal, invertebrate, and charcoal remains 
from species normally found in a colder and moister environment 
than that prevailing today. 
Good geologic evidence to augment that from the fauna and flora 
was obtained from the excavations in three main Folsom sites. The 
animal bones and artifacts at the original location in the northeastern 
corner of New Mexico (pl. 3) came from a stratum of dark clay con- 
taining gravel lenses and small concretions of lime, a deposit left by 
an old bog or water hole. Extending several feet above this layer 
were sediments consisting of highly restratified earth that have been 
identified by some geologists as belonging to the close of the Pleisto- 
cene or last ice age and by others as representing early Recent. All 
agree, however, that their age closely approximates the transition 
between the end of the Pleistocene and the beginning of the Recent. 
In the Black Water Draw between the towns of Clovis and Portales, 
180 miles south of the Folsom site in eastern New Mexico, the as- 
semblage of bones and cultural material is found in a bluish-gray 
deposit that is believed to be the bottom of old lake beds that cor- 
relate with the high-water stage of ancient Lake Estancia located 
some distance farther west (Howard, 1935; Antevs, 19352). Gen- 
eral opinion is that Lake Estancia was at its maximum during a plu- 
vial period when there was much heavier precipitation and tempera- 
tures were lower, an era corresponding to the final stage of the Pleis- 
tocene, and the bones and implements are regarded as dating from 
that time. At the third site, the Lindenmeier, north of Fort Collins 
in northern Colorado, the situation is somewhat different. At that 
