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Figure 1: Available marine bathymetry datasets for the study area.

The -10m Mesolithic scenario highlights the limited overlay

between the potential for submerged prehsitoric

and nearshore geophyscial surveys.

The recent Outer Hebrides Coastal Community Marine

Archaeology Pilot Project (OHCCMAPP) combined the

study of three themes: Marine Resource Exploitation,

Maritime History & Transport and Submerged Prehistory

Potential in preparation for major research projects.

A strong focus on working with local people with deep

and detailed knowledge of the marine environment has

produced a rich cultural heritage background to this

thematic work which has enabled greater results thanwould have been otherwise possible.

This approach has culminated in the development of

biotope-based palaeogeography models that bring

together the marine resources, maritime transport and

palaeogeography themes in the Sound of Harris. By

integrating local Holocene relative sea-level (RSL) models

(Jordan et al.2010), existing regional RSL models and

limiting points (Shennan et al.2006; Ritchie 1985),

publically-available LiDAR and multibeam bathymetry

coverage and field data a number of prospectionmodels have been developed for submerged

prehistory particularly for the Mesolithic and

Neolithic periods (Fig 1, Table 1).

Table 1: Palaeogeography parameters for selected archaeological periods.

Palaeogeographic reconstruction and submerged prehistoryHuman colonisation, dispersal and sea crossings, seafaring,

Model Date Range Bathymetry MHWS Source

BC/AD MRSL mOD m OD

-7000 6000 -10 - Shennan et al.(2006), Gregory et al.(2005),

Bishop et al.(2010)

-7000 6000 -8 - Peltier et al.(2002), Gregory et al.(2005),

Bishop et al.(2010)

-7000 6000 -5 - high-stand scenario, e.g. including

contribution from Storegga tsunami < 6100 BC.

Gregory et al.(2005), Bishop et al.(2010),

Smith et al.(2006)

-7000 6000 -15 - low-stand scenario. Gregory et al.(2005),

Bishop et al.(2010), Lambeck (1993),

Peltier et al.(2002)

-3800 -3.89 -1.39 Jordan et al.(2010)

-2500 -2.39 0.11 Jordan et al.(2010)

Mesolithic A

Mesolithic B

Mesolithic C

Mesolithic D

Early Neolithic

Late Neolithic

Sound of Harris

Scotland

England

Wales

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With regards to the Mesolithic, the enduring feature of

the palaeogeography is a wide open seaway linking the

Minch (the seaway between western Scotland and the

Outer Hebrides) and western seaways of the British Isles

to the Atlantic across the Sound of Harris (Fig 2). This

provides critical context to maritime transport during the

Mesolithic and the in situ remains of lithics and organic

remains at Northton, Harris (c. 6-7000 BC) which lies on

the Atlantic side of this palaeo-seaway. Other key findings

include the implications for the entire submergence of

the Neolithic coastline which include a bias against thepreservation of evidence for marine resource exploitation

in the Neolithic (Fig 3). Furthermore, the importance

of faults as bathymetric deeps affording access to the

interior by small vessels (such as logboats or currachs)

is significant in the south of the study area (Fig 4).

A number of high-potential locations have been

identified for future survey (Fig 5).

1 1 1 1 1,2Andrew Bicket , Genevieve Shaw , Kitty Foster , Karen Nichols , Jonathan Benjamin

1 Wessex Archaeology, Coastal & Marine, 2 University of Edinburgh

References

Jordan, J.T., Smith, D.E., Dawson, S., Dawson, A.G., 2010, Holocene relative sea-level changes in Harris , Outer Hebrides , Scotland , UK, Journal of Quaternary Science 25:115-134.

Shennan, I., Bradley, S., Milne, G., Brooks, A., Bassett, S., Hamilton, S., 2006, Relative sealevel changes , glacial isostatic modelling and ice-sheet reconstructions from the British I sles since the Last Glacial Maximum, Journal of Quaternary Science, 21: 585599.

Ritchie, W., 1985, Inter-tidal and sub-tidal organic deposits and sea level changes in the Uists, Outer Hebrides, Scottish Journal of Geology, 21(2): 161176.

Bishop, R. R., Church, M. J., Rowley-Conwy, P. A., 2010, Excavations at Northton, Western Isles of Scotland, 2010; Data Structure Report, Department of Archaeology, Durham University.

Peltier WR, Shennan I, Drummond R, Horton BP. 2002. On the postglacial isostatic adjustment of the British Isles and the shallow viscoelastic structure of the Earth. Geophysical Journal International 148: 443475.

Gregory, R. a., Murphy, E.M., Church, M. J., Edwards, K.J., Guttmann, E.B., and Simpson, D.D. a., 2005. Archaeological evidence for the f irst Mesolithic occupation of the Western Isles of Scotland. The Holocene, 15 (7), 944950.

Smith, D.E., Fretwell, P.T., Cullingford, R.A., Firth, C.R., 2006. Towards improved empirical isobase models of Holocene land uplift for mainland Scotland, UK. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 364 (1841), 949 972.

Lambeck K. 1993. Glacial rebound of t he British Isles. II. A high- resolution, high-precision model. Geophysical Journal International 115: 960990.

Acknowledgements

Full details can be found at:

Contains OS Open Data Crown Copyright 2013. Bathymetry datasets sourced from Marine Scotland (2013)and MCA (2012). SRTM: http://srtm.csi.cgiar.org

www.wessexarch.co.uk/alba

Figure 2: Mesolithic period palaeogeography scenarios for the Sound of Harris c.7000 6000 BC.

Archaeological sites and submerged peats are highlighted.

Figure 3: Neolithic period palaeogeography scenarios for the Sound of Harris (c.2500 and 3800 BC).

Archaeological sites and submerged peats are highlighted.

0 10 km

0 10 km

0 5 km

Figure 4: Influence of fault lines upon maritime accessibility

within the Sound of Harris, North Uist coast.

Figure 5: Areas of potential: preservation of shelf sediments and submarine topography of archaeological interest

for submerged palaeolandscapes in the Sound of Harris.

rospection from the Outer Hebrides, Scotlandsland colonisation and exploitation of ice margins