Short title - .....Continental shelves in the Quaternary

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National Reports for 3rd Year - continued

Romania - [Gabriel Ion] In 1998 the main event concerning IGCP-396 was the very interesting new discoveries obtained during the international research cruise BLASON (Black Sea Over the Neoeuxine) carried out in April-May, aboard of the French oceanographic research vessel "Le Suroit".

This cruise has been done in the framework of French-Romanian co-operation (IFREMER-GeoEcoMar) with participants from Germany (University of Hamburg - Institute of Biogeochemistry and Marine Chemistry), U.S.A. (Lamont-Doherty Earth Observatory) and Ukraine.

The principal objective of this collaborative project was to bring together experts in fluvial, deltaic, coastal, shelf and deep-sea fan sedimentary processes in order to examine with high-resolution tools the late Pleistocene and early Holocene transgression of what had formerly been the exposed rim of the world's largest and deepest freshwater lake.

The survey accomplished 4,500 km of multi-channel seismic reflection profiling, 500 km of multibeam swath bathymetric mapping and acoustic backscatter imaging (in depths < 1 km) accompanied by extremely high-resolution digitally-recorded profiling with both sparker, mono-frequency and swept-frequency (CHIRP) sound sources, and 38 sediment cores targeted to sample the erosional and depositional landscapes and bedforms developed in glacial and post-glacial time.

To date the activities which have been carried out by all members of the Spanish Work Group are very dispersed with many small groups belonging to different organizations and institutions and working on continental shelves and slopes. A national meeting had been planed for September, 1998 with the main objective to diseminate the different work and to have a opportuinity to join together all groups working in Spain. Unfortunately this meeting had to be cancelled, but the plan is to have a National Meeting in 1999. A total of 68 persons working in Spain have expressed interest in the Project Relevant Meetings in Spain

1. 2nd Simposio sobre el Margen Continental Ibérico Atlántico : Cádiz. España. September, 17-20. 1997 Organization: Universidad de Cádiz. Facultad de Ciencias del Mar
2. 15th International Sedimentological Congress : Alicante. April, 12-17. 1998 Organization: International Association of Sedimentologists (IAS) & Uninv. de Alicante
3. Asamblea Hispano-Portuguesa de Geodesia y Geofisica: Aguadulce (Almeria), February, 16-20. 1998 Organization:Univ. Almería
4. Aios de Observaciones Sismoligicas en San Fernando: San Fernando, September, 17-18. 1998 Organization: Real Observatorio de la Armada. ROA
5. V Congreso Nacional de Geologia. Portugal: Lisboa. November, 18-20.1998 > Organization: Instituto Geológico e Mineiro & Sociedade Geológica de Portugal
6. XIII Congreso Bienal de la Real Sociedad española de Historia Natural. Conservación Ambiental, :Vigo, July, 6-10. 1998: Organization: Bienal de la Real Sociedad española de Historia Natural-Univ. de Vigo.

The Russian National WG of IGCP396 includes 32 members from 16 institutions at the moment of the preparation of this report (September 28, 1998). Our WG regards the continent/shelf/deep sea correlation of Quaternary sediments in Russia as the main general objective for the period of the project implementation. PRIMARY ACTIVITIES IMPLEMENTED DURING 1997 - 1998

1. Detailed stratigraphic schemes of the Black Sea, the Sea of Azov and the Caspian Sea were elaborated for the coasts of Russia and the bordering states. Their coorelation with the Mediterranean was established. Geochronometric support for the time scales was prepared (Lomonosov Moscow State University; Geological Institute, Russian Academy of Sciences).

2. Palaeogeographic maps for the Black Sea and the Caspian Sea during the characteristic periods of the Quaternary were prepared (Lomonosov Moscow State University; Institute of Oceanology, Russian Academy of Sciences; Rostov-on-Don State University).

3. Main regularilties of the Russian Arctic coastal evolution during the Quaternary were established. Palaeogeographic maps for the scenarios of warm climate and the sea level similar to the present one or slightly higher were compliled (Institute of Oceanology, Russian Academy of Sciences).

4. A series of predictive maps of coastal evolution under sea-level changes was prepared on the basis of palaeogeographic analogues for the European Russian sea coasts (Lomonosov Moscow State University).

Research of relevance to the project IGCP-396 is underway at several establishments in the UK: both University and organisations such as the British Geological Survey. At the time of the deadline for submission of individual reports for the current year, five centres of research reported representing 34 individuals ( as named on this year's publications).

The UK hosted the 1997 Annual Meeting of the Project IGCP-396 in Durham at which approximately 40 delegates from various countries were present. Many of the UK participants also attended the National IGCP-367 meeting held at the University of East Anglia in September 1997. Two UK participants (Keith Tovey and Jeremy Lloyd attended the International Meeting of IGCP-396 in Goa.

Two representatives from the UK (Prof Mike. Paul, and Dr Keith Tovey) visited the Netherlands during the year with a view to promoting collaborative work on issues of relevance to IGCP-396. Contacts in the Netherlands included Dr George Postma and the Netherlands Geological Survey.

Current work of relevance to IGCP-396: University of East Anglia include:

1. Jan Alexander who has been studying the dispersal from river mouths involving theory and a case study in Australia, Buredkin Delta). In addition, she is involved in model testing of sediment movement in sand bed river sequences at the Hydraulics Research Station, Wallingford.

2. Julian Andrews, Brian Funnell, Neil Chroston, Barbara Maher, Paul Dennis, Tim Jickells and Alastair Grant, supported by Ian Boomer, Greg Samways and Rina Jones have been working on two areas funded by the UK LOIS Project.
   1. Holocene Evolution of the North Norfolk Coast

      This work is providing a new framework for interpreting how barrier coasts might respond to increased rates of sea-level rise .Predictions about how this barrier coastline might respond to increased rates of regional sea-level change caused by global warming, or climatic events like increased storminess, require an understanding of how specific segments of the coastline have responded over millennial timescales. This longer-term evolution provides the baseline information for decision making and management strategy. It is likely that sandy sediment supply is limited on the North Norfolk Coast (NNC). This implies that the barriers will continue to move landward, probably at increased rates relative to today, suggesting that parts of the NNC will become more vulnerable erosion and flooding.

   2. Carbon, Nitrogen and Sulphur storage in Holocene Estuarine Sediments

      In the Humber, conservative calculations show a net decrease in organic carbon deposition from about 0.33 x 106 tonnes in the palaeo-estuary to no more than 2.5 x 103 tonnes today, a >99% reduction in potential organic carbon storage capacity. The total modern yearly sulphur deposition is approximately 2% of its value 2000 years ago. Removal of saltmarsh and associated brackish - freshwater wetland suggest that suspended sediment and associated organic carbon and sulphur are currently bypassing former (Holocene) storage areas and may be impacting North Sea biogeochemical cycling.

3. Tristam Hardman completed his PhD having researched the Microfabric and Geochemistry of Holocene Halimeda bank sediments in the northern Great Barrier Reef. In conjunction with Keith Tovey he has been assessing quantitatively the size distributions of nanograins which form part of the microfabric.

4. Keith Tovey continued his work developing image analysis methods for studying sediment microfabric.

   1. A significant development was the generation of an algorithm which allows feature sizes to be measured directly on grey-level images.

   2. Both basic and enhanced algorithms have been developed and will be reported in brief for the first time at the Goa meeting of IGCP-396.
   3. These algorithms were applied to work done by Tristam Hardman (see above), while an adaptation of the method allowed sand size distributions to be estimated directly from photographs as part of the study of Jan Alexander (see above).
   4. Arising out of discussions at the 2nd Annual meeting, Keith Tovey has been developing algorithms to specifically examine high-resolution sequences directly from photographs of cores. The current state of this work will also be reported at Goa.
   5. Active work continues with Mike Paul (Heriot Watt) - see below for a fuller account

1. Mike Paul and Bev Barras: Continuation of work generated from Bothkennar - concentrating on sedimentology, geotechnics and depositional history of the sequence. In ICGP terms this is a high resolution study of the late Quaternary infilling of an estuary, with applications to geotechnical engineering and estuarine environmental management.

2. Mike Paul and Pauline: Continuation of work on the outer continental shelf/upper slope in collaboration with BGS. This is part of a regional study of seismic facies, geotechnical (particularly void index) profiles and depositional processes. Current work has concentrated on the area due north of Shetland (vicinity of Miller Slide and North Sea Fan) with an emphasis on sedimentology and fabric.

3. Mike Paul and Keith Tovey (University of East Anglia - see above): Application of image processing to SEM/mineralogy in Quaternary sediments. This aims to extend technical capabilities of the method and to establish validity in sediments of more complex mineralogy, with a view to use a a tool for mapping pollutants at the micro-scale.

Anne Hinton reports that her work on Tidal modelling is continuing and one relevant publication has appeared during the year. She is co-organiser of a meeting on 'Tidal Action, Tidal Processes and Tidal Effects on Coastal Evolution' in Brazil, 3-9 October, 1999, which is of relevance to IGCP-396. The official sponsor of this meeting is the International Geographical Union's Commission on Coastal Systems.

1. Dr. Jeremy Lloyd has continued his research in marginal marine environments. Principally this has involved the use of foraminiferal and thecamoebian assemblages from isolation basin sequences for high resolution sea level and environmental reconstruction. A series of contemporary analogues of these environments (rock lipped tidal ponds) are being studied from NW Scotland. Investigation of the usefulness of the stable isotope signature (oxygen and carbon) from foraminifera from these sites is also underway.

2. Dr. Bill Austin has continued his high resolution studies from the St. Kilda Basin concentrating on the last glacial-interglacial cycle. Collaboration continues with James Scourse and Gillian Scott (now at Durham University) researching the vertical structure and seasonal stratification of the Irish Sea. Oxygen and carbon isotopes are being used from foraminifera in this relatively shallow environment to reconstruct past oceanographic regimes.

Most research has been completed for the BGS Western Fontiers Association comprising 14 commercial companies and the Health and Safety Executive, all with operational interests in the areas of 17th Round Licences in the UK designated area.

Most of the research has been applied to assessing the hazards presented by instability associated with Quaternary and Neogene formations deposited in the shelfedge and the deeper-water environments west of Scotland. Continental shelf research has principally taken the form of lithostratigraphic correlation between the land in SE England and the adjacent offshore areas in the southern North Sea, for which a report is currently in preparation.

The key item to report was a Core Workshop: Late Quaternary Depositional Systems of the Northern Gulf of Mexico Shelf organised by Dr. John B. Anderson, and assisted by Michelle Fassell, Antonio B. Rodriguez, and Julia S. Wellner of the Department of Geology and Geophysics,at Rice University, Texas. The following is an abstract.

Sequence stratigraphy is a valuable tool for stratigraphic correlation, and provides a framework for characterizing depositional packages using seismic and well log information. We now are in a phase in which the method is being tested for its value in predicting the distribution of sedimentary facies within a sequence stratigraphic context.

One approach is to image the condensed systems tracts formed during the high frequency glacial eustatic cycles of the last 400,000 years. The objective is to see how these systems responded to rising a falling sea level, and to evaluate the influence of other forcing mechanisms , such as tectonics and climate, on deposition.

The northern Gulf of Mexico provides and unparalleled natural laboratory for this type of study because it includes a myriad of depositional environments, the sediment yield of different rivers that supply sediment to the region is highly variable, shelf gradients vary by a factor of two, climate ranges from humid to arid, and because there is a wealth of oil company platform borings and sediment cores that add lithological constraints for seismic facies interpretations and for chronstratigraphic analysis.

This core workshop utilizes a data set consisting of over 20,000 kilometers of high resolution seismic data and several hundred oil company platform borings and sediment cores from the Florida, Alabama, Louisiana and Texas continental shelves. These data are used to examine the evolution of and variability in late Quaternary depositional systems and stratal stacking patterns associated with the last glacial eustatic cycle.

Emphasis will be placed on testing the assumptions made in sequence stratigraphic models that attempt to relate stratal stacking patterns to the distribution of depositional systems on continental shelves and slopes. A set of four paleogeographic maps showing depositional systems of the early highstand, late highstand, lowstand, and transgression will be used to examine variability in depositional systems from one shelf setting to the next and for examining those factors that control this variability, such as shelf physiography, climatic setting and sediment supply, and eustasy.

A number of case studies of individual depositional systems will be examined, focusing on reservoir-scale sand bodies. Sediment cores, seismic records, sediment isopach maps and other data will be used to illustrate the geometry and facies architecture of these sand bodies. The course will conclude with a summary of what we know and what we need to know to develop better models for subsurface reservoir prediction using sequence stratigraphic and well log data.

contact geo.micro@uea.ac.uk