NO, 4 SAN JON DISTRICT, NEW MEXICO ROBERTS 25 



Samples from the deposits representing the bottoms of the various 

 filled-in ponds were examined for fossil diatoms by Paul S. Conger, 

 custodian, section of diatoms. United States National Museum. 

 None were found, however, and no help toward determining the 

 age of the deposits was obtained from this possible source of 

 information. 



SUMMARY AND DISCUSSION 



From excavations on the northern rim of the Staked Plains, the 

 brakes below, and the plain of the Canadian River valley south of 

 the town of San Jon, N. Mex., came an interesting sequence of 

 projectile point and other artifact types that sheds some light on 

 the aboriginal occupation of that portion of the Southwest. Faunal 

 associations and geologic horizons give good indication of relative 

 age, but more evidence is needed before an actual chronology can 

 be suggested. The investigations to date tend to corroborate impli- 

 cations observed in finds made elsewhere, particularly with respect 

 to the relationship between certain kinds of projectile points, yet 

 do not furnish the complete and detailed evidence essential to a 

 thorough understanding of developments in the earlier stages of the 

 lithic industries in the western Plains. Later types of stone tools 

 and implements probably were made by Indian groups known to have 

 hunted over that area. On the basis of present knowledge, however, 

 it is not possible to assign specific forms to definite peoples. There 

 unquestionably was a mixing of materials in late times when various 

 bands swept back and forth across the region, following the great 

 herds of bison, camping at the same water holes, and otherwise 

 making use of the same territory. Until sites attributable to occu- 

 pancy by single groups have been worked and the character of the 

 artifacts made and used by them is established to the extent that 

 they are readily recognized the identification of different objects in 

 a mixed series as the product of a definite tribe is not feasible. The 

 best that can be done is to suggest certain probabilities. 



The oldest horizon in the district is represented by one type of 

 projectile point occurring in association with the bones of an extinct 

 species of bison and coming from a stratum in which mammoth 

 bones and teeth also are present. The point is of a type that might 

 be called Indeterminate Yuma, but in order to clarify a confusing 

 situation with respect to that classification it is designated the San Jon 

 point. Indications are that it may be contemporaneous with the 

 Folsom horizon, one of the oldest thus far established, but more 



