Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648986
Title: Recent carbonate sediments of the west coast of Scotland between Ardnamurchan and Islay
Author: Cucci, Maurice Allen
Awarding Body: University of Edinburgh
Current Institution: University of Edinburgh
Date of Award: 1979
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Abstract:
Deposits of temperate water biogenic carbonate sediments occur on the inner western continental shelf of Scotland. A general survey of their extent and composition has been made and facies maps prepared for the area. One small portion of the area, the Sound of Iona, was studied in detail to ascertain the origin of the carbonates and their bed-forms and to attempt an estimate of local carbonate productivity. In Iona Sound, barnacles and molluscs are the most important bioclastic constituents with locally dominant coralline algae (maerl). Barnacles predominate over most of the Sound because they grow prolifically on the coast, are readily broken down to sand size and easily transported. Four facies are recognized in Iona Sound: 1) rippled sand, 2) sand waves, and sand ribbons, 3) in situ maerl, and 4) relict glacial drift deposits. Seismic studies indicate that 1) bioclastic sediment is thickest at the sand wave facies diminishing in thickness laterally; 2) the sand waves are draped, over a bathymetric high formed from glacial drift; 3) in the northern Sound glacial drift formed deltaic deposits. Facies are controlled as follows: the rippled sands are deposited under the influence of wind-generated waves and low-velocity tidal currents which winnow fines and create low bedforms; the sand waves are formed by the drag of tidal currents crossing the bathymetric high, sculpting a hierarchy of bedforms; an associated sand ribbon is formed by tidal current acceleration following deflection by an island; maerl forms because of 3-sided wave shelter, current deceleration, erosion resistant morphology and a greater growth rate of the algae over the ambient sedimentation rate. Glacial deposits were exhumed by scouring or lie exposed in areas of very slow sedimentation, or both. Recent carbonate sedimentation is related tc Pleistocene glacial activity which created a complex coastal and seabed form trapping terrigenous sediment (termed "basinal terrigenes") in bathymetric deeps, lochs and convolute coastlines. Shallow-water, terrigene depleted, indurated rock localities of the inner shelf are exploited by carbonate producing organisms with high productivities shedding abundant bioclastic material to form "island margin carbonates".
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.648986  DOI: Not available
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