Pap N^f" 2^lT TEXARKANA RESERVOIR — JELKS 69 



ranges, or antagonistic human neighbors, may result in a distribution 

 pattern with an abrupt termination in a zone of heavy concentration. 

 Unless the barrier completely encompasses the distribution, however, 

 there would normally be a lensing out of the type at the margins 

 not restricted by the barrier. 



A similar sort of distribution occurs within a particular site; 

 that is, the greatest quantitative representation of a type will usually 

 be found in areas of heaviest occupation within the site, with a 

 peripheral scattering on all sides. Again, a barrier such as the con- 

 fining walls of a house within a site can result in a distribution pat- 

 tern of uniform thickness with abrupt margins instead of the char- 

 acteristic peripheral thinning. 



Thus a cross section through the areal distribution of a type would 

 normally reveal a central zone of relatively heavy concentration with 

 a lensing out toward the periphery. Actually there will usually be 

 localized "hills and valleys" in such a cross section reflecting varia- 

 tions in regional population, local selectivity, temporal factors, etc. 

 But these do not alter the basic lens shape of the pattern, although 

 they compound it. 



If we may accept the axiom that a normal distribution pattern 

 is lens-shaped, it follows that one factor governing the quantity of 

 a particular type found at a particular archeological site is the 

 geographical position of the site. That is, a site near the center of 

 distribution of a type would be likely to contain more specimens of 

 that type than a site located in the marginal part of the type's 

 distribution. In brief, the geographical location of an archeological 

 site, with respect to the distribution patterns of the types occurring 

 therein, is one of the determinants of type frequencies in the site. 



Tlie dimension of time also imparts a lens shape to a distribution 

 pattern, but in a vertical direction at right angle to the geographical 

 pattern of distribution. The inherent shape of the vertical, or tem- 

 poral, distribution pattern is amply demonstrated by Ford's seriation 

 graphs (Ford, 1951 and 1952). The quantity of a particular type 

 in a particular site, therefore, depends on the temporal, as well as 

 the geographical, position of the site. 



The cultural phenomenon of selectivity also helps shape distri- 

 bution patterns. Selectivity can only be operative, however, among 

 peoples who have an opportunity to accept or reject a certain trait ; 

 in other words, they must be located within the geographical and 

 temporal limits of a type's distribution if they are to have an op- 

 portunity to exercise an option. Therefore, when an archeological 

 site is excavated, the artifact inventory will necessarily be dependent 

 not only on the cultural factor of selectivity, but also on the extra- 

 cultural factor of geographical and temporal position of the site. 

 If the distribution patterns of two or more types should coincide 



