NO. I ARCHITECTURE OF PUEBLO BONITO — JUDD 225 



This little P. Ill house has since been destroyed but beneath it, as 

 seen in 1920 and later, layered alluvium extended to right and left, 

 the patient deposits of floodwaters flowing over a grassy plain 

 (Bryan, 1954, pi. 6, upper). In Chaco Canyon where the gradient 

 has always been a modest one, summertime floods formerly advanced 

 slowly and dropped their silty burden on the way. 



Bryan traced his buried channel up and down canyon a distance 

 of approximately 5 miles and recorded his observations at 23 num- 

 bered sites. While so doing he repeatedly found proof of human 

 occupancy coincident with deposition of the main valley fill. He col- 

 lected Pueblo I potsherds as much as 20 feet below the surface, while 

 those attributable to P. Ill, the period of Pueblo Bonito and its 

 contemporaries, rarely occurred below 4 feet. Of known P. I pit- 

 houses in the canyon, two stood with roof levels at a depth of 6 feet 

 or more ( Judd, 1924, p. 403 ; Roberts, 1929, p. 71 ; Bryan, 1954, 

 p. 32). 



The fact that water-borne sediments were sometimes laid down 

 so gently that even charcoal in ancient hearths was not appreciably 

 disturbed evidences both a low gradient and a long-continuing grass- 

 covered surface. We did no testing south of the present arroyo, but 

 on the north side we met floodwater silt layers repeatedly. Although 

 not always deposited as evenly as those tmderlying the little P. Ill 

 ruin near Bryan's section 4, they are undeniable. 



When exploring the Northeast Foundation Complex (fig. 11), 

 we exposed 22 inches of excellent Late Bonitian masonry at Station 1 

 upon a sturdy foundation 4 feet 7 inches high (pi. 48, right). At 

 6 inches deeper, or 7 feet from the present sandy surface, is a pave- 

 mentlike sheet of floodwater silt, smooth as a kitchen floor. And 

 wherever we dug deep enough throughout that whole foundation com- 

 plex we came upon the same or a similar silt layer. 



Close under "Hillside Ruin" are five quadrangular fireplaces 

 (pi. 47, lower). A test pit 4 feet 10 inches deep between the second 

 and third revealed another adobe pavement, floor-smooth but cov- 

 ered by debris of reconstruction and wind-blown sand. Presumably 

 that pavement is a continuation of the one we had previously 

 encountered outside Room ISA — the pavement that prompted our 

 5- foot-wide trench to the lower terrace below the Braced-up Cliff 

 (pi. 42, left) ; the same pavement, presumably, as that at a depth of 

 4 feet outside Room 187 where it is overlain by 20-24 inches of 

 blown sand. 



