Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.734436
Title: An experimental approach to spore/pollen taphonomy
Author: Holmes, Phillip Lee
Awarding Body: University of London
Current Institution: Royal Holloway, University of London
Date of Award: 1989
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Abstract:
A study has been made of the transport and deposition of spores and pollen in water bodies. In particular the effects of differential transport on the aerial distribution of spores/pollen in lake sediments is highlighted. Work from both laboratory experiments (using a 7.5m flume fitted with a sediment loop) and from the field (Silwood Lake, Berkshire) has yielded data showing that the differential transport of spores/pollen is selective, primarily by grain size. The grain density is, however, of secondary importance. Experiments have shown that the nature of the bed material (and associated bedforms) over which the water flows will affect the rate of spore/pollen deposition. For most spore/pollen types sorting will only occur in flows whose velocity is ≤35cm.sec-1. For spores smaller than 35μm in size the flow velocity has to drop below 20cm.sec-1 for sorting to occur. These figures are, however, derived from flume experiments and should be viewed with caution when used in conjunction with field data. Differential selection of spores may also take place at higher velocities in the flow adjacent to the bed. The work is presented alongside a review of spore taphonomy, although this concentrates on the transport of spores and pollen to lake sediments rather than their fate once within the sediment. The field data has yielded results consistent with previous work. The pollen record obtained from the lake sediments is representative of the 'extra-local' vegetation in the area (the lake is lOOm wide, 2m deep, and in a relatively sheltered area). The stream input to the lake shows a bias toward non-arboreal pollen types. Current velocities in the lake are low (generally ≤5cm.sec-1) and the distribution of spores in the surface sediments of the lake show considerable evidence of having been sorted by the water movements. A method for predicting the aerial distribution of spores in the sediments of small lakes is also presented.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.734436  DOI: Not available
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