Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.592096
Title: The weathering of layer-silicate minerals, with special reference to chlorite, in some Scottish soils
Author: Bain, Derek Charles
Awarding Body: University of Aberdeen
Current Institution: University of Aberdeen
Date of Award: 1975
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Abstract:
Fifteen chloritio soils of varying drainage classes developed on different parent Materials from the Loch Awe area, Caithness and the Southern Uplands have been examined using X-ray diffraction, differential thermal analysis, X-ray fluorescence spectroscopy. electron microscopy and optical and other techniques. Particular attention was paid to the clay mineralogy which revealed that all the soils are immature and that weathering is at an early stage. Chlorite, which is iron-rich, generally persists throughout the profiles varying little in amount and chemical composition between horizons and, where identifiable, is the IIB polytype. Oxidation of iron modifies the thermal characteristics of the chlorite in all the freely- drained noils but usually, as would be expected, only in the surface horizons of gleys. Laboratory experiments indicate that after oxidation, the hydroxide sheet dehydroxylates in two stages. Regardless of type or drainage class, in most soils chlorite weathers only slightly, by vermiculitization around the edges of flakes. In one podzol, the absence of any trioctahedral mineral in the A2 horizon together with the marked loss of iron and magnesium from the clay fractions indicate that the chlorite, a thuringite, present in the lower horizons has been dissolved out. In this soil, percolating organic compounds may have complexed iron and aluminium from the chlorite structure and translocated than to the B2 horizon while also causing the weathering of dioctahedral mica to interstratified mica-interlayered montmorillonite. Chlorite dissolution seems to occur only in highly leaching, acid environments where there is evidence of translocation of organic matter. Another podzol contains unusually high levels of titanium, particularly in the clay fractions, in the form of cryptocrystalline anatase amorphous to X-rays. Kaolinite is a common minor constituent end seems to have an inherited rather than a pedogenic origin.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.592096  DOI: Not available
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