Examination of Quaternary deposits in Spanish Valley near Moab, Utah, revealed a complex pattern of soil development and distribution on alluvial fans and terraces previously correlated by Richmond (1962) with glacial deposits in the La Sal Mountains. Longitudinal profiles show downstream convergence of terraces and burial of older surfaces in the middle portion of the valley. In this area, buried soils at two localities have carbonate accumulations similar to those on Placer Creek terraces considered to be of Bull Lake age. The reappearance of inset terraces in lower Spanish Valley suggests that the depositional history has been complex or that the middle part of the valley has subsided since Placer Creek time. Progressive changes in the morphology and content of pedogenic carbonate were used to correlate deposits. Soils developed on gravel of the latest Pleistocene Beaver Basin Formation (Pinedale age) have thin carbonate coats on clasts, display Stages I and II carbonate morphology, and contain 7 to 9 gm/cm 2 of pedogenic CaCO 3 . Placer Creek deposits have up to 75 cm of continuous CaCO 3 ; three sampled profiles contain about 36 to 38 gm/cm 2 . Carbonate contents of soils on the middle Pleistocene Middle Member of the Harpole Mesa Formation are similar to those of Placer Creek soils; however, a buried argillic horizon preserved at one locality suggests that the Harpole Mesa deposit is older. The Stage IV K horizon on older Harpole Mesa alluvium has a strong platy structure and a well-developed laminar horizon; about 182 gm/cm 2 of pedogenic CaCO 3 is present in one profile. Sandy alluvium in the Lower Member of the Harpole Mesa Formation has reversed magnetic polarity. A similar pedogenic calcrete containing 98 to 130 gm/cm 2 of accumulated CaCO 3 overlies magnetically reversed deposits on an erosion surface southwest of Green River, Utah. Using a minimum age of 700,000 years for the magnetically reversed sediments, maximum carbonate accumulation rates for this portion of Utah range from 0.14 to 0.26 gm/cm 2 /1,000 years.

Abstract In April 1983, Spanish Fork Canyon, Utah, was engulfed by a massive landslide that dammed Spanish Fork Creek, creating a lake. The slide pushed and finally buried sections of the Denver & Rio Grande Western Railroad line and U.S. Highways 6, 50, and 89, which for decades had been located in Spanish Fork Canyon. When motion of this massive debris flow and/or landslide complex finally ceased, almost the entire 6,800-ft-long (2,040 m) and 800-1,100-ft-wide (240–330 m) mass, more than 200 ft (60 m) thick had moved. Spanish Fork Canyon, ~600 ft (180 m) wide at the location of the landslide, was filled to a depth of ~220 ft (66 m), causing a lake to form on the upstream side. Data indicated that small displacements at the toe of the slide, adjacent to the Denver & Rio Grande Western Railroad, had been recorded since the early 1900s. Motion was correlative with years of above-average precipitation. Thus, the extraordi-narily high precipitation of 1983, which was only ~2.2% higher than the previous record high precipitation of 1875–1876, added sufficiently to the ground-water regime to cause slow motion to develop in early April, followed by rapid acceleration in mid-April. Borings placed in 1984 indicated the existence of an artesian condition, the pressure level ranging from 25 to 65 ft (7.5 to 19.5 m) above ground surface near the toe of the slide. Other borings drilled at a later date provided samples from which strength parameters were determined. Test data indicate strength as low as 17.5° angle of internal friction and 210 lb/ft 2 cohesion. Information obtained from all of these studies strongly suggests that had a surface-drainage system with horizontal (subsurface) drains been constructed prior to failure, landslide motion could have been prevented. Analyses indicate that a readily achievable lowering of the hydrostatic pressure on the slide planes would have produced a factor of safety greater than 1.0.

Abstract Late Archaic to Early Woodland (4500–3000 years bp ) Stallings Island Culture fibre-tempered plainware pottery is found from northern North Carolina to NW Florida and is often separated into two temper groups (Stalling and Orange series) based upon fibre type. Thirty-four sherds were studied to determine textural or mineralogical characteristics to assist in form and type separation. This study finds that only a few of the sherds were dominated by fibre. The fibre is visible as secondary porosity (voids) with some carbonized remains and exhibits specific shape and orientation at different locations within the sherd. Only two sherds had carbonized stem fragments that allowed identification of the Spanish moss ( Tillandsia usnedoides ). The remainder of the Crescent site plainware pottery has such low (to no) fibre contents as to be indistinguishable from similar age sand-tempered Thorn’s Creek wares. The identity and textural features of the fine-grained aplastic minerals (quartz, feldspar, biotite and opaque minerals) in the paste are similar in both fibre- and non-fibre-tempered sherds, and this suggests that the materials used are consistent with sediment extraction from a fluvial coastal plain or estuarine setting. These observations indicate that the degree of fibre incorporation in these sherds may be related to the specific clay source (or manufacturing location) or represent examples of an evolving pottery manufacturing process within the Stallings Island Culture.