Culture and Ecology of Chaco Canyon and the San Juan Basin

The Preceramic Period 69tool production, and tool use. Vierra (1994) also usedthe types of materials and the locations of their sourcesto outline possible areas utilized during an annualround by groups using the central San Juan Basin.In summary, Chaco Project surveys covered allphysiographic situations within the park boundaries.A typology and criteria for cultural subdivisions of thePreceramic adaptation were established. The dataconfirmed Gordon Vivian's impression that Preceramicsites were present on Chacra Mesa, but theevidence included a few sites in the canyon bottom, aswell as on ridges or mesa ledges in other areas of thepark (Hayes 1981).There is limited evidence for the use of the areaaround Chaco Canyon from Paleoindian through LateArchaic. The Paleoindian evidence consl' ..... "t".c\ -- ..... ""'. f on ....... Iv Jfive diagnostic projectile points. The more robustArchaic evidence indicates that approximately 28 sites,plus two isolated points (Figure 3.2), are locatedwithin the current park boundaries. The greatestnumber of Preceramic sites were occupied during theMiddle and Late Archaic; points from the additionallands survey peaked in Late Jay and Middle Archaic.Gillespie (1985) thought that the Late Jay and Bajadaperiods represented moist summers with an increase inplants and animals, the availability of pinon nuts, andprobably the peak abundance of bison, followed by aless mesic but cooler period (San Jose-Armijo) duringwhich there would have been less abundance ofresources. Thus, the low numbers of sites/points(which mayor may not be truly representative of theuse of the area) indicate larger populations duringthese moister periods. Whether these sites representseasonal use by mobile groups or use by a limitednumber of people living in the Chaco area was notascertained. The documentation of nonlocal materials(obsidian and basalt) indicates either large territoriesfor mobile groups or trade among Archaic people.ExcavationsInitially, Thomas W. Mathews was responsiblefor the preceramic site excavations. Sites with culturalhorizons such as the Paleoindian, Archaic, andBasketmaker II horizons, were considered "on thebasis of single phase occupations where no earlier orlater manifestations would be likely to complicate the,.Figure 3.2. Examples of Archaic and BasketmakerII dart points and preforms.(Taken from Cameron and Young2005.)excavations and confuse the picture" (Mathews 1979).One goal was to reassess the existence of BasketmakerII sites; which were thought to resemble the LateArchaic sites, with the addition of cultigens. Toobtain necessary data, rockshelters and cave loci, aswell as open sites without ceramics, were considered.Further considerations were Archaic flaked stoneforms, open site configuration and location, presenceof "figure-eight"-shaped surface depressions surroundedby broken cobble or other stone paving, andlocation near or on dunes.Five sites, considered to be Archaic, wereselected for excavation. All were on the north side ofthe Chaco Wash, either around Cly's Canyon(29S1126, 29S1116, and 29S11118)(Figure 3.3) or thenext canyon to the west (29S11156 and 29S11157)(Figure 3.4); none were on Chacra Mesa. Once excavationswere under way, 29SJ1118, a lithic site with