NO. I ARCHITECTURE OF PUEBLO BONITO — JUDD 23 1 



or the sample taken from to 10 inches deep, probably contained a little 

 organic matter, for it percolated faster than the others . . . required about 

 24 hours to wet the 6-inch column. In the field this, of course, would be much 

 longer. Nos. 10, 9, 8, and 7 went slower than No. 11. It required about 48 hours 

 for these columns to become wet. This takes us to SO inches deep. . . . Below 

 that level the soils seemed almost impervious, that is, all the samples will 

 probably require a month each for the water to move downward through the 

 6-inch layer. I do not think I have ever handled a soil quite so impermeable 

 to water as are these last six samples. 



The Chaco Canyon soil, in all the levels that you sampled, is badly defloccu- 

 lated and for the reason that it contains an excess of sodium and a scarcity of 

 soluble calcium. . . . 



I can say without any doubt that these soils . . . will not take water. I do 

 not believe, even under the most favorable conditions, that such soils can be 

 successfully cultivated. ... If all the soils that were available to agriculture in 

 Chaco Canyon are as bad as these samples, I think you have one reason at 

 least to explain why the Bonitians left the valley. I do not believe an Indian, 

 with his primitive methods, could handle any soil like this.^ 



A year after receiving the foregoing- report Pit No. 3 was deep- 

 ened at the suggestion of Dr. Bryan and Late Bonitian potsherds 

 were collected at depths between 10 and 15 feet (Bryan, ibid., p. 58). 

 These finds established the fact that, unwittingly, I had located this 

 particular 1922 test within the banks of Bryan's post-Bonito channel. 

 Our soil samples, therefore, represented a varied alluvium transported 

 from a distance and not fields cultivated by the Bonitians. 



Nevertheless, that transported alluvium originated in the same 

 place, upcanyon, as had the annual accretions comprising the main 

 valley fill. And some of those annual accretions, upcanyon, assuredly 

 were cultivated. But, if all local soils were as impervious to water 

 as were those from Test Pit 3, and we have no reason to believe 

 otherwise, farming for a livelihood in Chaco Canyon would have 

 proven increasingly discouraging and, as Breazeale points out, the 

 Bonitians would have had ample reason for moving elsewhere. 



Each of our 11 samples from No. 3 pit, originally 9 feet 3 inches 

 deep, was not only deficient in soluble calcium but contained sodium 

 bicarbonate, or black alkali, in approximately the same amount, 0.144 

 percent. If as little as 0.144 percent of black alkali can so tighten a 

 soil that days rather than minutes are required for water to percolate 

 through, then local agriculture eventually would have been recognized 

 as altogether unproductive and unprofitable. In Breazeale's pithy 

 summation : "Unless we can get water into a soil we stand little show 

 of getting any crop out of it." 



I I desire once again to acknowledge my obligation to Messrs. Scofield and 

 Breazeale for their cooperation in these studies. 



