Record Details
Water loss and uptake in clayey subsoil materials
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Water loss and uptake in clayey subsoil materials |
| Names |
Stannard, Davis Robertson
(creator) Knox, Ellis (advisor) |
| Date Issued | 1965-05-28 (iso8601) |
| Note | Graduation date: 1966 |
| Abstract | B and C horizon samples from twenty four selected profiles along a north-south transect in the Willamette Valley were examined for possible correlation between shrinkage properties and kind of clay minerals present. Observations of linear shrinkage, weight loss from a condition of maximum plasticity, and changing character of X-ray diffraction patterns were made on 'tablets' of the untreated soil material during drying and subsequent heating at various temperatures to 950°C. Differential-thermal analysis of undried 'whole soil' samples was also made. On the basis of the X-ray diffraction patterns, soil samples were placed in five groups and a pair of B and C horizon samples from a profile representative of each group was selected for characterization of clay mineral suites by conventional X-ray diffraction analysis and differential thermal analysis. Differences found in clay mineral suites of the five profiles justified the initial grouping and provided a basis for the attempt to observe correlations between shrinkage behavior and the kind of clay minerals present. Clays of the two-layer lattice type (kandites) were found dominant in most samples from the Salem Hills. A more detailed distinction of these was made between the red, acid, over-deepened colluvium dominated by kaolinite (with iron and aluminum hydrates associated), and those relatively shallow soils lying on profoundly weathered tuffaceous sediments which were characterized by dominance of poorly crystalline clays of both two-layer and three-layer lattice type (probably hydrated halloysite and smectite of the beidel-Iite-nontronite sequence) . Clays of the three-layer lattice type (micaceous, or showing expansion properties) were dominant in soils on the valley floor. A further distinction of these was made between the silty soils showing micaceous material as well as other material of varying degrees of expansion, and those soils on alluvial clay which appeared to contain most or all of which was smectite (probably of the beidellite-nontronite sequence ). Detailed examination of shrinkage curves for two soil samples containing the same amount of clay, but of different mineralogy (kaolinite vis a vis smectite), failed to reveal differences in shrinkage due to differing lattice type. In general, a difference in shrinkage was not observed between those samples on the transect with dominantly three-layer lattice clays and those with dominantly two-layer lattice clays. Most of the variation in shrinkage could be attributed to variations in particle size and surface area, as measured by clay content and water distinctions in clay mineralogy on field under other circumstances was loss. The possibility of making the basis of shrinkage in the not excluded. |
| Genre | Thesis/Dissertation |
| Topic | Soils -- Oregon -- Willamette River Valley |
| Identifier | http://hdl.handle.net/1957/48032 |
