SOUTHWESTERN ARCHEOLOGY — ROBERTS 509 



Spanish group. This belief was strengthened by the unsatisfactory 

 results which most of the workers obtained when they endeavored to 

 develop a sequence on the basis of legendary evidence, by comparisons 

 between artifacts, and by the state of preservation of the ruins. 



For some reason stratigraphy was largely disregarded despite the 

 fact that it had long proved extremely useful in Old World arche- 

 ology. Not a few investigators held, and students were taught, that 

 there could be no stratigraphy in the Southwest because the remains 

 were only those of a single people, the Indians, 



Stratigraphy was recognized in a few cases as indicating relative 

 dates for material, but it was not until the present phase of south- 

 western researches that it received due consideration as an important 

 source of evidence. N. C, Nelson, of the American Museum of Nat- 

 ural History, demonstrated the validity of the method when, begin- 

 ning in 1912, he used it in New Mexico, He, as well as other field 

 men, had recognized variations in the kinds and styles of pottery 

 associated with ruins and village sites and believed that these differ- 

 ences had definite significance beyond that of merely being charac- 

 teristic of the places where they were found. Accordingly, he chose 

 a number of ruins known to be inhabited pueblos during the early 

 Spanish occupation. By working downward from top to bottom in 

 the adjacent refuse heaps, he determined the sequence of the princi- 

 pal pottery types of the Rio Grande region and in consequence the 

 main chronological periods for the district.^ At about the same time 

 Kidder and Guernsey were using stratigraphy to establish the rela- 

 tive ages of several types of remains in the Kayenta district in 

 northeastern Arizona, and Morris was applying the principle to his 

 excavations at the Aztec Ruin in northern New Mexico. Subsequent 

 projects, Hodge at Hawikuh, Kidder at Pecos, Judd in the Chaco 

 Canyon, were conducted with a full consideration of the importance 

 of this kind of evidence. Since that time stratigraphy has become 

 one of the accepted routines in the technique of excavation. 



To aid him in the study of his material Nelson developed a system 

 of tabulations and percentages which not only showed the fluctua- 

 tions in the pottery from a .single site, but which proved of value in 

 making comparisons between the types found at various ruins. Kid- 

 der employed an adaptation of the method at Pecos,^ Kroeber used it 

 successfully in the Zuili region,^ and Spier obtained excellent results 

 in a survey of the Zuiii and Little Colorado districts by following an 

 elaborated form of it.^ Briefly stated, the technique makes possible 

 a relative dating of sites on the basis of the percentages of the 



* Nelson, 1916. 



"Kidder, M. A., and A. V., 1917. 



* Kroeber, 1916. 



6 Spier, 1917, 1918. 



