Culture and Ecology of Chaco Canyon and the San Juan Basin

------- --Environment and Natural Resources 29swNE10200 100 OmFigure 2.3.Schematic cross-section of alluvial fill in the Chaco Wash (levels 7-9). Remnants of earlierfill are located along the margins of the canyon and are partially buried by modernalluvium. Horizontal lines indicate widespread inundation of the canyon floor by sedimentsfrom the headwaters and are connected with filled-in entrenched channels, laminatedswales, and yazoo channels. A) remnant gravel deposit of level 7 with blocks of alluvialfill; overlain by soils. B) sandy soil containing pottery. C) Gravel reworked into laterchannel. D) Broad swale filled by laminated clay derived from the headwaters, overlainby canyon floor deposits. E) Swale filled with laminated clay associated with 3,700-yearoldfill in buried channel to right. G) Small water-control feature. H) Deeply buriedlaminated silty clay with soil developed on top of deposit. I) At least 38 m of fill abovebedrock floor of canyon (level 9); water table at 12 m. J) Complex arroyo cut and fillabout 3,700 years old. K) Pottery-bearing channel 3 to 4 m deep filled to present surfaceof canyon floor. L) Modern Chaco arroyo wall. M) Modern inner Chaco channel. N)Modern inner floodplain aggraded after 1934. 0) Indented terrace (former floodplain priorto 1896). P) Stone slabs associated with pithouse. Q) Canyon floor sediments derivedpredominantly from the headwaters. R) Buried channel(s) with pottery and rocks at base.S) Undated buried channel filled with sandy sediment with no backwater facies. T)Shallow channel. U) Thin wedge-shaped headwater-derived deposits pinch out againstdeposits from the canyon margin. V) Undated buried channel. W) Relict sediments ofprevious episode of canyon fill with well-developed reddish-brown soil, truncated at topby Holocene (6,000 yrs) sediments. X) Buried tributary channel containing pottery. Y)Sediments from canyon margins predominate. (Taken from Love 1983:Figure 4.)