UBC Theses and Dissertations
Genesis of a Podzol sequence on the West Coast of Vancouver Island Bhoojedhur, Seewant
A study was undertaken on the pedogenesis of a Podzol sequence of soils on the West Coast of Vancouver Island. The area is one of abundant rainfall and rather luxuriant vegetation. The soils occur on relatively level topography (glacial fluvial deposits) and have varying degrees of development of placic (pan) horizons. The objectives of the study included characterization, classification and genesis of the soils, based on physical, chemical and mineralogical investigations. Four soils were chosen for the study. Three of the soils comprised the Ucluelet soil series, while one soil was a member of the Wreck Bay soil series. The soils were described morphologically, sampled and selected analyses were performed on the major genetic horizons. More detailed analyses, including differential thermal analyses, were conducted on the placic materials. The soils were classified into the Canadian Classification Scheme as as follows: Ucluelet I Placic Ferro-Humic Podzol Ucluelet II Orthic Humo-Ferric Podzol Ucluelet III Placic Humo-Ferric Podzol Wreck Bay Gleyed Placic Ferro-Humic Podzol Analyses of the placic materials indicated, that although the material appeared vitreous in the field, no crystallinity could be determined by X-ray diffraction. It appeared that the major component of the placic horizon is composed of iron and organic matter, probably in some intimate association. It was observed that the placic horizon could form in materials of initially low iron contents. From the foregoing observations the following chronosequence of soil development appears to be justified: Orthic Humo-Ferric Podzol (Ucluelet II) → Placic Humo-Ferric Podzol (Ucluelet III) → Placic Ferro-Humic Podzol (Ucluelet I) → Gleyed Placic Ferro-Humic Podzol (Wreck Bay) The differences in pedogenic age of the three Ucluelet sites can be attributed to degrees of "churning" by the trees at these sites.
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