The first chapter is a brief review of the geology, geography and the soils in Iceland, with particular reference to peat soils. The field work (Chapter 2) included measuring the thickness of organic layers between dated tephra layers and it was found that the mean rate of thickening of the peat was slowest 0.1 mm/year in the period 4500 to 2900 B. P., but fastest 0.26 mm/year in the period since 1104 A. D. Two profiles were selected for detailed study, one in north Iceland, and the other in west Iceland. Micromorphology, physical, and chemical properties were investigated, see-Chapters 3,4 and 5 respectively; and a review of peat soil classification and the application to the soils studied is given in Chapter 6. The main constituents observed in the thin sections were underground plant organs, fine organic material, and mineral material. Woody, cork, epidermal and lign ifi ed tissues were best preserved, parenchymatous tissue had predominantly disappeared, but was present in some leaf and herbaceous root residues. Conspicuous secondary mineral phenomena included bog iron, pyrite and siderite; and in Chapter 7a hypothesis is proposed for the formation of s ider it e. The range of hydraulic conductivies was from about 9.10-3 to 1_ 10-4 cm sec-1 . The moisture content at saturation was mainly > 90 , and 10 to 20; 4 at pr 4.2. Bulk density was mainly 0.1 to 0.2 g cm-1 in organic layers and up to 0.5 g cm-1 in those rich in mineral material. Most samples shrunk to less than half the original volume upon oven drying and it was concluded that it is important to consider shrinkage when moisture retention is determined. The pH in water was highest at 6.8 in the top layer of the profile in north Iceland, but was mainly 4.4 to 5.0 in the organic layers. The loss on ignition of the organic layers varied mainly from 40; ') to 90 The C/N range was normally 17 to 30, but lowest at 15 in the top layer of the profile from North Iceland
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:457556 |
| Date | January 1978 |
| Creators | Gudmundsson, Thorsteinn |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=185809 |
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