Ecological and sedimentological studies on china clay waste deposits in Mevagissey Bay, Cornwall

Knight, Alan Paul

(1989)

Knight, Alan Paul (1989) Ecological and sedimentological studies on china clay waste deposits in Mevagissey Bay, Cornwall.

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Abstract

Prior to 1973, the St Austell china clay industry discharged fine grade waste into local rivers which carried the waste into Mevagissey Bay, Cornwall. The clay waste, a mica and quartz rich silt buried a marine shell gravel substrate by up to 2 metres. The china clay waste and natural sediments on the surface and subsurface of Mevagissey Bay have been studied and the distribution of live and dead benthic faunas analysed. The benthic faunas presently living in the china clay waste and surrounding shell gravel have been compared to faunas from a similar survey taken during the period of peak discharge (1968) and during the reduction of discharges (1970-1973). Within the bay are four different benthic communities whose distribution reflects the amount and nature of china clay waste present. The only notable changes since the the cessation of dumping being the colonisation by a Tellina tenuis community of a previously azoic muddy substrate near the point of waste discharge into the bay. This research suggests that benthic communities in areas subjected toinert solid pollution will change to communities typical of the grain size of the waste. Each community can be recognised by a distinctive death assemblage although these show little resemblance to the composition of the original living community. Different taphonomic processes control the preservation within each community. Radiographs and microscopic examination of impregnated box core samples reveal the important effect of bioturbation on the orientation and position of shells and shell fragments within the substrate. Since the cessation of china clay waste dumping in 1973, shell debris formed by local benthos has began to transform the soft, fine grade substrate into a shell gravel. It is predicted that it will take within the order of 10,000 years for the substrate to resemble the original shell gravel now lying below the china clay waste.

Information about this Version

This is a Accepted version
This version's date is: 1989
This item is not peer reviewed

Link to this Version

https://repository.royalholloway.ac.uk/items/e77fc85a-3f3b-4542-add0-a49aa83df617/1/

Item TypeThesis (Doctoral)
TitleEcological and sedimentological studies on china clay waste deposits in Mevagissey Bay, Cornwall
AuthorsKnight, Alan Paul
Uncontrolled KeywordsEcology; Sedimentary Geology; Environmental Science; Biological Sciences; Earth Sciences; Health And Environmental Sciences; Bay; China; China Clay; Clay; Cornwall; China Clay; Cornwall; Deposits; Ecological; Mevagissey; Sedimentological; Studies; Waste
DepartmentsDepartment of Geology

Identifiers

ISBN978-1-339-60353-7

Deposited by () on 31-Jan-2017 in Royal Holloway Research Online.Last modified on 31-Jan-2017

Notes

Digitised in partnership with ProQuest, 2015-2016. Institution: University of London, Royal Holloway and Bedford New College (United Kingdom).


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