Culture and Ecology of Chaco Canyon and the San Juan Basin

208 Chaco Project Synthesis120 in Aztec [Morris 1928:333]) are late developments,possible due to a scarcity of pine posts of theproper size (Lekson 1984a).Other features may be related to constructionproblems. Filling of rooms may have reinforced wallsor insulated rooms. Buttressing of round rooms mayhave served to relieve stress or reinforce walls.Lekson (1984a:34) suggested that the large protrudingstones on the exterior walls may have been useful inerecting scaffolding or bonding buttresses. Otherfeatures relate to use of the buildings; e.g., balconieson the north side that may have provided shade(Lekson 1984a:37). Use of natural features suggeststhat the builders were inflexible in their choice oflocation and orientation. Although Lekson suggestedthat height may have been a concern, this may havebeen less important because height was achieved bymUltiple stories in several buildings.Summary. Kluckhohn (1939a) had proposedthat the differential adoption of architectural changesin great houses and small house sites might be due totime lags; if so, it could be attributed to small siteresidents who were more conservative than their greathouse neighbors (Kluckhohn's 1939a). Yet this differentialadoption of architectural features (lined pitstructures, enclosed ramadas, pithouse-to-kiva transition)that occurred around A.D. 900 in great houses,but around A.D. lO00s in the small sites, could beattributed to several factors (TruellI986:316-317). Ifwater was scarce and stone abundant, adobe would nothave been the material of choice for constructing largeedifices, even if it were as structurally strong. Ifsmall sites were used only seasonally, there would belittle need to enclose the above-ground rooms; yetduring the A.D. 900s there was much remodeling andnew construction in these houses, which suggest morepermanent occupation.Truell (1986:391) noted a heavier use of smallsites in the Fajada Butte area during the Red Mesaceramic period, and Windes (1993:315) commentedon the possible abandonment of Marcia's Rinconduring the Gallup ceramic assemblage (A.D. 1040150to 1100) and increased concentrations of small housesin the early A.D. l100s in the central canyon. Architecturalevidence suggested closer ties to the southduring earlier years, and closer ties to the west andnorth later. The core-and-veneer masonry in smallhouses in the A.D. l100s exhibited both a blockypattern and types III and IV masonry, possiblyindicating no time lag, a copying of the latter type, ora temporary resurgence in construction. Truell (1986:319) concluded that the more intense use of small sitesprobably indicates differential use, "the nature ofwhich is not yet clear."In addition to the burst of construction at greathouses, the construction of roads, shrines, signalingstations, and stone circles during the Classic Bonitophase (A.D. 1050 to 1100) provided Judge (1989)with data to propose that Chaco was a periodicpopulation center within the San Juan Basin.Although there may have been a small year-roundresident popUlation, there could have been an influx ofpeople to participate in ceremonies on a scheduledbasis. As Lekson pointed out, this would explain theheavy investment of labor into permanent structuresthat required low maintenance. Yet, he asked, whywould people who spent so much energy to constructlarge empty rooms not spend a little more effort toequip them with fireplaces that would make their staymore comfortable?Hayes (1981) indicated that there were severalsite clusters present in the canyon as early as BasketmakerIII and that these clusters shifted through time.Lekson (1984a:267) proposed that these clusters mayrepresent communities during the initial growth ofgreat houses, but that they probably have several antecedents.Schelberg (1982a, 1982b) proposed that ahierarchical social organization existed from BasketmakerII. By around A.D. 1050, construction in thecentral canyon (Pueblo Alto; Chetro Ketl; and, in the1080s, Pueblo del Arroyo) led Lekson to define"downtown Chaco" as the central area. Thisdefinition would be expanded to include the area fromPueblo Alto on the north to Tsin Kletsin on the south,and from Kin Kletso on the west to Chetro Ketl andpossibly Hungo Pavi on the east. Combined with theevidence from human burials and their associatedgrave goods, Akins (1986 and Akins and Schelberg1984; Schelberg 1982a, 1982b) proposed that theClassic period represented a stratified socialorganization.Lekson concluded that the local evolution ofconstruction form and techniques suggests that nooutside influence, especially during the later dates sug-