ISSN:0267-8179    

DOI:10.1002/jqs.3390040101

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractInternational Geological Correlation Project 200 ran from 1983 to 1987 and was a major stimulus to sea‐level research. The results arising from the project were very varied, with much new data collected and analysed, but there remain some problems for international researc

ISSN:0267-8179    

DOI:10.1002/jqs.3390040102

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractThe course of Irish sea levels during the late‐Holocene is not well‐known, yet it is an understanding of this period that will prove crucial in the definition and management of future sea‐level changes. The coastline of Ireland embraces wide environmental and glacio‐isostatic contrasts, which serve and, to some extent, control sea‐level events at both local and regional scales, making definitive resolution of relative sea‐level changes difficult. In the southwest, the picture is of inexorable relative sea‐level rise. Studies in Co. Kerry show a gradual submergence of terrestrial facies, by estuarine and, in places, marine materials. Pollen and diatom studies, together with14C dates, suggest a decreasing rate of relative sea‐level rise in the last 2500 years, often associated with geomorphological changes. Sites on the south coast of Ireland confirm the evidence from the southwest. In Cork Harbour, recent relative sea‐level rise since 2100 BP was responsible for marginal land submergence, while elsewhere rising water levels appear to have caused rapid barrier migrations and coast erosion. Palaeoenvironmental evidence from this region suggests a distinctive pattern of sea‐level change, associated with sedimentary and/or crustal dynamics, which is not encountered elsewhere in northwest Europe. The overall rate of relative sea‐level change on the south and southwest coasts falls between 0.6 and 1.1 mm/year over the last 5000 years. In the north, there is a clear east to west variation in relative sea‐level trends, following an isostatically‐controlled peak (+3 to −1 m OD) between 6500 BP (east) and 3500 BP (west). Falling sea levels from 3500 to 1500 BP have been followed by a general slow rise, although there are still local anomalies to this pattern, most noticeably at Malin Head, where sea level is currently falling at 2.4mm/year. Relative sea‐level signatures in Ireland differ markedly between the north and south coasts. Furthermore geomorphological and ecological contexts of this rise vary from east to west, providing a complex all‐Ireland fram

ISSN:0267-8179    

DOI:10.1002/jqs.3390040103

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractFourteen distinct sedimentary environments have been recognised in the surface sediments of the intertidal zone of the North Norfolk coast. Nine of these can be distinguished in borehole samples on the basis of sedimentological and micro‐palaeontological characteristics. They comprise: gravel; channel sand; intertidal sand; intertidal silty sand; intertidal mud and marsh creek; lower salt marsh; upper salt marsh; dune sand; and peat.Sediment accumulations have been penetrated to a depth of −8 m OD and basal peats dated by14C back to 8410 ± 50 years BP. An overall rate of sediment accumulation (and subsidence) of about 1 m per thousand years is indicated. There is considerable persistence of sedimentary environments in the same areas during up‐building, but some erosion and roll‐over of the coastal barrier system has occurred. Evidence of positive and negative sea‐level tendencies are present in the record, but the main development of the tract is determined by sediment supply to the beach and marshes; positive sea‐level tendencies occur at c. 6610, 5970, 4630 and 2790 BP, negative sea‐level tendencies occur at 4520 to 4450 and (pos

ISSN:0267-8179    

DOI:10.1002/jqs.3390040104

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractMorphological mapping and stratigraphical investigations have identified surface and buried relict marine features in the inner Moray Firth area. The features consist of a buried gravel layer formed during the Loch Lomond Stadial, a buried beach of early Flandrian age, and surface beaches and estuarine flats of mid‐late Flandrian age. Analysis of the altitudes of morphological features has identified two buried and five (possibly six) surface glacio‐isostatically tilted raised shorelines. The steepest shoreline is associated with the buried gravel layer and slopes down towards N20°E at a gradient of 0.20m/km. Younger shorelines have lower gradients between 0.16–0.03m/km. The shoreline sequence combined with published data defines relative sea‐level movements in the area during the last 11000 years. The inner Moray Firth shorelines are correlated with similar features in other areas of Scotland which include the Main Lateglacial, Main Buried and Main Postglacial Sh

ISSN:0267-8179    

DOI:10.1002/jqs.3390040105

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractDetailed stratigraphic, palaeobotanical (diatom and pollen) and radiometric evidence from a sequence of buried estuarine deposits, buried peat and overlying estuarine ‘carse’ deposits at Wester Rhynd, in Lower Strathearn, suggests the occurrence of two brief marine incursions between the abandonment by the sea of a buried estuarine flat, probably the Low Buried Beach, at about 8765 ± 75 BP, and c. 8500 BP. The first incursion, shortly after 8565 ± 85 BP, caused bottom‐living marine diatoms to be thrown without clastic material onto the rapidly accumulating terrestrial peat. The second, bracketed by dates of 8485 ± 80 and 8510 ± 85 BP, deposited an extremely thin (1 mm) layer of fine sand that interrupts an otherwise unbroken buried peat succession covering the period 8765 ± 75 to 7710 ± 70 BP. The marine diatom, lithostratigraphic and14C evidence together are consistent with a storm, storm‐surge or tsunami origin for these events, which are recognised principally from the diatom evidence, having left no mark in the

ISSN:0267-8179    

DOI:10.1002/jqs.3390040106

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractA thin, regionally extensive, laterally persistent sand layer identified within the Holocene coastal sequences of eastern Scotland, dated to 7000 years BP, is suggested to be a tsunami deposit. The likely source of the tsunami wave is the earthquake induced second Storegga Slide on the Norwegian continental slope at least 750 km northeast of the deposit.

ISSN:0267-8179    

DOI:10.1002/jqs.3390040107

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractDifferences in the timing of maxima and minima and shape between sea‐level curves from the western Forth valley, lower Strathearn, inner Moray Firth and eastern Solway Firth areas of Scotland are interpreted as being due to differences in isostatic uplift and different methodologies used to interpret the basic data. Possible changes in the relative rates of uplift between areas suggest that the practice of applying the western Forth ‘model’ of relative sea‐level change to other parts of Scotland must be que

ISSN:0267-8179    

DOI:10.1002/jqs.3390040108

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractCrustal downwarping has occurred throughout southern and south‐eastern England and most of Wales for at least the last 4000 years, but the type of movement in some areas of southern and eastern England is more complicated than simple linear subsidence. Highest estimated rates of subsidence (since 4000 BP) are for the Thames Estuary and Norfolk (up to 2 mm/yr). Glacio‐isostatic processes have resulted in uplift in northern England and mainland Scotland. The rates of uplift have decreased throughout the Holocene; estimates for the present range from zero in south Lancashire and the Tees Estuary to over 1 mm/yr (though less than 2 mm/yr) in central Scotland.Over 400 sea‐level index points, from the databank of 904 cases collected for IGCP Project 200, are grouped into 15 main areas and used to investigate the nature of crustal movements in Great Britain since 8800 BP, but there are significant deficiencies in available data which constrain the ana

ISSN:0267-8179    

DOI:10.1002/jqs.3390040109

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

ISSN:0267-8179    

DOI:10.1002/jqs.3390040111

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY