Culture and Ecology of Chaco Canyon and the San Juan Basin

Basketmaker III to Pueblo I 113and distribution of postholes that supported uprightsfor roofs in the open spaces (plazas) between thestorage rooms and the pit structures. At 29SJ627,where adobe walls were not shared, the uncoveredwall bases were narrow (10 to 17 cm wide). Exceptfor two work areas at 29SJ724, the surfaces were atthe level of the surrounding area. Floors wereleveled, and possibly sloped to drain. Surface. treatments varied from none to adobe to clay,probably depending on the source of material. Slaborplaster-lined hearths were the most common featurefound within the ramadas, but sometimes none, ortwo, were present. The plaza work areas became formalizedduring this period.In summary, architectural analyses confirmed thechanges in pit structures from shallow to deeperthrough time, the transformation of the antechamberinto a ventilator, and the linking of cists to formabove-ground storage rooms separated from pitstructures by a plaza work area. The presence of twolarger villages with great kivas at different ends of thecanyon introduces the possibility of popUlation centerswith integrative structures as early as Basketmaker III.Data from the excavation of very few early structuresat 29SJ423 precludes comparisons of smaller structuresbetween these two villages. Truell did suggest,however, that there may be two different house stylesrepresented in different areas of the canyon(Shabik'eshchee Village vs. the area around FajadaButte as exemplified by 29SJ299 and 29SJ628).The concept of multifamiliy use of Pueblo I siteswas reviewed by McKenna, who proposed that growthmay be due to the accommodation of nonindigenouspopulations. How these possibly different populationswere integrated and whether or not they wererelated to groups outside of Chaco Canyon had not yetbeen addressed. (See also Gwinn Vivian [1990:147-148, 154], who viewed the Pueblo I period as a timewhen migrants from the southern part of the San JuanBasin moved into the Chaco Basin and shared itsresources with earlier inhabitants.Evidence for Chacoan LifestylesThe inhabitants of Chaco Canyon depended onboth agriculture and hunting to sustain their society.Flotation samples with macrobotanical remains fromsix sites indicate heavy reliance on crop productionand little reliance on economic annuals, which appearonly in a patchy fashion and in very low numbers inthese early sites (M. Toll 1993a). Com contributed53 percent to economic remains during the BasketmakerIII through Pueblo I periods; in later periods,that portion would decrease to 26 percent.Horticultural remains present in Toll's samplesincluded common beans, squash, and 12-rowed corncobs(versus lO-rowed cobs during Pueblo II) .Because row number is generally considered a genetictrait, Toll considered the possibility that these earlyfarmers may have been growing a different geneticstrain of com than the later i!l_habitants of the canyon.Yet undeveloped kernel rows, as well as reduction insize of the cob, can also be attributed to stress inducedby low moisture, temperature, and mineral content ofsoil.In her comparative analysis of cobs fromBasketmaker III and Pueblo I sites in the San JuanBasin, M. Toll (1993a) found that the 12-rowed cobsdominate the collection from Chaco Canyon, and fromLA 26749, a site located near Crownpoint. For thesample from small sites to the west and south, 45percent are eight-rowed. When cob diameters werecompared, however, there was little variation amongsites. Those from Chaco are the largest (13.6 mm);by Pueblo II, cobs from sites in Chaco share small cobdiameters with Bis sa'ani, sites excavated during theENRON Project, and Navajo Mine sites. Also duringthis later period, predominantly 12-rowed com hasbeen recovered from Salmon and sites in the La Platavalley, and their cob diameters are larger than the onesfrom Chaco. Although a larger sample size is needed,Toll's results could suggest differences between areasin the San Juan Basin, but how well these differencesin row number and cob size reflect genetic andenvironmental stress, let alone social ties, needs muchfurther investigation.Data on squash and bean remains are fewer andless definitive. Most squash remains are difficult toidentity as to species. M. Toll did identify C. Mixtaseeds at 29SJ724, which contrasts with C. pepo seedsfrom Bis sa'ani and Pueblo Bonito, which wereintroduced early and are most widespread. Becauseunburned seeds at Bc 288 indicate that there is somemorphometric variation among varieties, dimensionsof two bean seeds from 29SJ628 were found toresemble those from later proveniences at 29SJ629,