Culture and Ecology of Chaco Canyon and the San Juan Basin

278 Chaco Project Synthesisleadership may have been related to environmentalfactors; Sebastian wanted to explain how powerevolved in more detail than Judge had presented.Sebastian recognized four problems that must beovercome by leaders. They include suppression ofsegmentation; legimitization, or institutionalization;~ompetition; and succession. Suppression of segmentationmay have been less of a problem than the othersdue to the unique location of Chaco Canyon within thecentral San Juan Basin. The mesas and arroyos thatcollect available water for agriculture in ChacoCanyon contrast with the open plains that immediatelysurround the canyon. This physiographic settingwould have constrained some people from movingaway without good reason or to a destination thatprovided the necessities they sought.For pattern 1 (A.D. 900 to 1020), Sebastian(1992:114-120) accepted the Chaco Project model,wherein a labor-intensive strategy on the most productivelands at the confluence of major side drainagesystems provided individuals within these corporategroups with surplus. During periods of low productivity,labor to assist in the construction of greathouses would be rewarded with food. Through theirgenerosity, productive corporate groups would haveengendered obligations from unsuccessful relatives andneighbors. Continued success in favored locationsmight indicate that they had been favored by thesupernatural. Pe.riods of major downturns, however,may not have been easily resolved; as a result, no oneleader or group would be able to maintain power forthe entire period. Because great house constructionevents never occurred simultaneously during thisperiod, Sebastian proposed that different leaders in thethree early great houses competed for labor. Althoughshe prefers not to label this as a "Big-Man" society,she suggested that problems with leadership successionexisted.During pattern II (A.D. 1020 to 1100), overallprecipitation improved. The downturns that occurredwere not as severe as those earlier, and storagecapabilities never did drop below a one-year supply.A different power base was needed to account for themultiple construction episodes and peaks in laborinvestment. Although Sebastian had no problem withJudge's (1983a, 1989) proposal that turquoise wasassociated with this power base, she questioned howwell the Chacoans controlled the turquoise trade.Even if production and use of turquoise wouldguarantee a central role for Chaco in the economicsystem that brought subsidies into the canyon, theproblem of succession needed to be solved. Shesuggested that the overall continuing good rainfallpattern would reinforce the leadership roles of thoseliving in the earliest great houses and retaining the useof the best land; and continued construction of publicbuildings would increase the belief that participationin the system led by these mediators was legitimate.If successful ritual events were sponsored, morefollowers would join, and access to desired resourceswould be forthcoming. Competitive displays bypatrons in the canyon would draw popUlations fromthe larger area into alliances. Advantages of institutionalizedleadership include the facilitation of informationand material exchange, promotion of social tiesthrough periodic gatherings, and a buffer against subsistencefailure through out-migration. Sebastian(1992:120-132) posited that the long-standing perceptionof the Chacoans' successful relationships withthe supernatural would have led to legitimization oftheir roles as intermediaries. At this point, followerswould owe goods and labor to their leaders to ensurecontinued intervention with the dieties on their behalf.As long as there were no catastrophic events, leaderscould train their chosen successors. Once the leadershiprole of the religious mediators was accepted, theproblem of succession would be solved.Why this occurred in Chaco Canyon and notelsewhere is attributed to two factors: the uniquegeographic location of the better watered canyon,where several groups settled and competed; and thecircumscription of this better agricultural area by thesurrounding plains, so that people were less apt tomove out. Leaders in the Chuska and San Juanvalleys lacked such circumscription.The drier periods between A.D. 1080 and 1100would have depleted social surplus or capital, andthere would therefore have been more demands on thepatrons of the system. Yet the massive class III andclass IV building episodes (Lekson 1984a) indicatethat leaders successfully supported large labor pools.Sebastian (1988, 1992) considered several possiblescenarios to explain the data, including patron use ofdownturns to increase power by providing food andmeeting obligations. In this scenario, Sebastian