Rock Matters: A Geological Basis for Understanding the Rock at the Ness of Brodgar

Rock Matters: A Geological Basis for Understanding the Rock at the Ness Of Brodgar

Martha Johnson writes about her research into non structural and non tool rocks found at The Ness of Brodgar.

All stone is rock but most rock is not stone. In the index or glossary of most geology texts there is no listing for stone, conversely, in most archaeology texts, there is no listing for rock.

This research has been structured to include rock in an archaeological setting. As a naturally occurring material composed of crystals or grains of one or more minerals, rock is not recognized in most archaeological sites until it has been quarried and placed upright in the ground; or it has been dressed for use in a foundation or wall; or it has been struck to form a sharp edge or ground into a tool. Until a rock is a stone something; standing stone, stone wall, flaked stone axe, or ground stone mace, it is not usually recognized as a material in its own right with information to provide. On many Neolithic sites there is incidental or non-structural, non-tool rock situated at occupation levels but this material is usually not recovered and recorded as either general or small finds.

The Rocks That Don’t Belong research project is investigating the non-structural, non-tool rocks recovered from the Late Neolithic site, the Ness of Brodgar, Orkney. These rocks, termed Foreign Stone for this research, are more often found on the spoils pile than in a finds tray. It should be noted the word “foreign” used in the archaeological finds classification, “Foreign Stone,” denotes rock originating from outside the area of excavation, not from another country. The recovery, recording and identification of these rocks as discrete rock (and mineral) species will add a petrological and geological dimension to post-excavation interpretation not commonly included in most archaeological settings.

During the 2013, 2014 and 2015 excavation seasons at the Ness of Brodgar, over 2000 Foreign Stone finds were recovered.  Each specimen has had the trench, structure and context recorded, their visible physical properties identified and recorded (colour, composition, texture/grain size, morphology…), and has had their specific rock (or mineral) species identified. Each specimen has also been examined for any evidence of heating.

The recording both archaeological and petrological data in this research will permit the cross referencing of rock species to structure or context. Though all rock recovered as Foreign Stone has been recorded and identified, the Foreign Stone of particular interest to this research involves those species not outcropping of the portion of the Stenness-Brodgar isthmus occupied by the Ness of Brodgar site. The recovery of these rocks at or near occupation levels, give indication of transport to the site during its period of use. Broad questions can then be asked concerning the presence of these rock species at the site.

The second portion of this research involved the compilation of all current and archival references regarding the location and description of any rock (or mineral) species found in Orkney. This species/location gazetteer permits an overall assessment of the rock types and species available within the Orcadian archipelago to people of the Neolithic. Questions can then be asked with respect to the distance(s) specific rock (or mineral) species recovered from the Ness of Brodgar could have been transported from its outcrop source(s) to the site.

Combining the knowledge of what rock species are found in Orkney and where they can be found with what rock species have been recovered from the Ness of Brodgar and where within the site they have been recovered generates the remaining post-excavation questions.   Specific questions will be posed to determine if there is any concentration of a specific rock species within a structure or within a context.


*Definition of petrology:  a science that deals with the origin, history, occurrence, structure, chemical composition, and classification of rocks

Fieldwalking in Orkney: End of Week One

Despite some seasonal weather, the first week of fieldwalking in the Orkney World Heritage Site buffer zone has finished and six fields have been walked to the east of the Loch of Harray.

23 intrepid volunteers have been out over three days in mixed weather, thankfully Wednesday was sunny and dry! We’ve walked fields around Maesquoy and Ness Farm (many thanks to the landowners). Views across the loch to Brodgar are spectacular from this part of the parish.

20160309_090151We’ve had some scatters of flint (including a knife and scrapper), an area of cramp (burnt material usually associated with pyres or burials) and some interesting post-medieval and modern pottery, clay pipes and a glass bead.

Due to the wet conditions over the winter few new fields have been ploughed this year, so we have been focusing on fields that were ploughed before Christmas. These are nicely weathered and finds are easily visible on the surface. We are collecting finds in 10m transects and logging the position with an centimetre accurate GPS (Global Navigation Satellite System – currently using US GPS Navstar and Russian Glonass constellations for the techi amongst you !) . Let’s hope the weather improves and the farmers can get ploughing soon.

More next week.

Orkney Archaeology Society

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Community Mapping Walk

The walk meets at 2pm at the Stones of Stenness car park on Sunday 6 March. Transport between the two sites will be provided – so no need to walk both ways. For more information please contact the Orkney Rangers on 01856 841 732 or email sandra.miller@hes.scot

Orkney locals are being invited to take part in a fun, organised walk through the Heart of Neolithic Orkney World Heritage site, as part of a project to create a ‘Community Map’ – which will record memories, sounds, stories and smells, rather than just the conventional roads and directions.

The finished map will be available online as a free download so that people can learn what matters to Orcadians about their World Heritage Site, and the hope is to produce a print leaflet version in future. 

The walk takes place on Sunday 6 March, and is being organised by Historic Environment Scotland and Dan Lee of the University of the Highlands and Islands Archaeology Institute, based at Orkney College. The stroll is aimed at people of all ages, who will be led by the World Heritage Site Rangers through the landscape between the stones of Stenness and the Ring of Brodgar.

Alice Lyall, World Heritage Site coordinator for Historic Environment Scotland said: “We know that the World Heritage Site means a lot to the Orkney Community, so I would encourage them to come and tell us specifically what aspects are important to them, and why. The community map concept is a great way to do this, as it is a medium which allows feelings and ideas to be expressed and recorded in an accessible and engaging way.”

“As well as being a worthwhile project, the walk will be led by our expert guides, and promises to be a lot of fun, so why not come along and share your favourite memories?”

As well as Sunday’s walk, Stenness Primary School at the West Mainland Day Centre will be contributing their memories and experiences to the map.

Historic Environment Scotland

 

A Splash of Colour from the Iron Age

Sometimes the smallest things tell us so much about people’s lives and yet at the same time raise so many questions.

A surprise discovery came in the form of a tiny splash of colour from the Iron Age! Cecily was processing some soil samples from The Cairns site on South Ronaldsay and her incredible eagle eyes spotted this beautiful multi-coloured glass bead! The object came from soil samples retrieved from the interior of the broch during the late occupation of the structure and date from about 100-150AD. It’s miniscule (yes that is a penny next to it!).

Glass bead 4In this image looking at the broken section of the bead you get to see the central perforation cut clean through. Most interesting you can see another pale green wedge of glass present on the left side of the bead. This is probably ‘cullet’, re-cycled glass from an earlier object partly melted down to make this bead. The source of the recyclate was probably a Roman vessel or bangle. Keep in mind this was found on South Ronaldsay in Orkney meaning of course that someone who lived or visited that site on the South Orkney Island of South Ronaldsay must have had access to Roman Britain at some point. But again some questions….was the Roman glass part of a treasured collection that took pride of place in someone`s life ? How did it come hundreds of miles from the nearest Roman settlement ? Was there regular contact between Roman Britain and Orkney ?

And then…..You wait all this time to get the first glass bead from the site and along comes another one – a much larger, whole one this time! This bead was thought to be fashioned from bone, but it can now be seen to be another yellow-amber coloured bead! But when put under the microscope the object takes on another character……

We now strongly suspect this is amber! Here it is under a microscope with top-light on the left and back-lighting on the right. On the back-lit image you can see the livid red translucent colour shining through the crust quite effectively. Now that raises a few more questions…where did it come from ? Did it come from The Baltic and how did it find it`s way to Orkney ? Is there another story this intriguing bead can tell us. In any event this would have been a treasured personal possession that someone would have dropped and lost in the hurly burly of life in The Cairns Broch.

The Cairns Bead
The second complete bead under the microscope.

There will be more on these small finds from The Cairns which tell us so much about the ordinary life of people that lived on South Ronaldsay two thousand years ago. Project leader is Martin Carruthers at martin.carruthers@uhi.ac.uk

Sharing Heritage: Orkney World Heritage Site Fieldwalking Project celebrates £9900 Heritage Lottery Fund grant

Fieldwalking near Maes Howe, Mainland Orkney
Fieldwalking near Maes Howe, Mainland Orkney

Orkney Archaeology Society has received a Heritage Lottery Fund (HLF) Sharing Heritage grant, it was announced today. This exciting project, Orkney World Heritage Site Fieldwalking Project: Learning About Archaeology Amongst Orkney’s World Famous Monuments, in the West Mainland of Orkney and led by Orkney Archaeology Society with partners at the University of the Highlands and Islands Archaeology Institute, has been given £9900 to undertake archaeological fieldwalking in the Heart of Neolithic Orkney World Heritage Site Buffer Zone.
The project, due to start this week, aims to follow the process of a fieldwalking project from discovery in the field, through a series of archaeology workshops, culminating in a temporary exhibition at Tankerness House Museum in Kirkwall in the autumn. The project is open to local volunteers who will be trained in field practice, lithics, finds processing, map making, presenting results, report writing and the final museum exhibition, which will be run as a series of workshops throughout the year. There will also be a fieldwalking workshop run in collaboration with the Historic Environment Scotland Rangers at Stenness Primary School.

Axe butt found in a field in the stenness area
Axe butt found in a field in the Stenness area

Fieldwalking involves the surface collection of artefacts in ploughed fields on a grid so that distribution patterns over larger areas can be observed. Fieldwalking around Maes Howe and along the Ness of Brodgar peninsula has the potential to add a significant layer of landscape interpretations to the area. This will enhance the results from the recent World Heritage Area geophysical survey undertaken by the University’s Archaeology Institute. This revealed a multi-period landscape of enclosures, settlements, rig and furrow cultivation and prehistoric sites beneath the ground surface. Fieldwalking has already proved fruitful in the area with the discovery of Barnhouse Neolithic settlement by Professor Colin Richards in the 1980s using this technique. The current fieldwalking project will recover artefacts from every period – for example material from the WWII camps around Maes Howe- not just prehistoric finds, bringing the story of the landscape up to the present day.
There are a number of trainee places available for the fieldwalking and various follow up workshops. Contact Dan Lee at the Archaeology Institute if you wish take part. Volunteers are also needed to help with all aspects of the project.
The project is funded by the Heritage Lottery Fund, and supported in kind by Historic Environment Scotland, Orkney Museums, and Professor Mark Edmonds. Orkney Archaeology Society would like to thanks local landowners for supporting the project and allowing access to fields.
Martin Carruthers, OAS Chair said:
‘Orkney Archaeology Society are excited by this fantastic opportunity to support the local community in discovering the wealth of heritage below their feet in the Orkney World Heritage Area. We are looking forward to the excitement, enjoyment and learning that such projects can bring.’

Dan Lee, Archaeology Institute Lifelong Learning and Outreach Archaeologist said:
‘We are thrilled to be working with Orkney Archaeology Society in such an iconic landscape to provide learning experiences in archaeology for the local community. We hope that local volunteers and trainees will enjoy bringing new stories to this important landscape’

Lucy Casot, Head of the Heritage Lottery Fund Scotland, said: “Sharing Heritage is a wonderful opportunity for communities to delve into their local heritage and we are delighted to be able to offer this grant so that the Orkney World Heritage Site Fieldwalking Project can embark on a real journey of discovery. Heritage means such different things to different people, and HLF’s funding offers a wealth of opportunities for groups to explore and celebrate what’s important to them in their area.”

Contact Dan Lee (University of the Highlands and Islands Archaeology Institute) for more details and to register as a volunteer 01856 569214 Daniel.Lee@uhi.ac.uk

The Cairns Character

 

Every now and then something turns up on an dig that just connects me with a living person from thousands of years ago. The Cairns Character was unearthed a few years ago in South Ronaldsay and for me, living in South Ronaldsay, it immediately made a connection.

I have included photographs of the site where he (is he a he or a she ?) was found and I have especially included pictures that were taken on one of those short Orkney days in winter – when perhaps this character was carved. I can see in my minds eye, someone sitting by the fire 2000 years ago, surrounded by their family – perhaps with a howling gale knocking at the door – gently carving a stone found on the beach. There`s a nose and two eyes and a little crooked smile….it`s a piece that connects me personally with the living from the Iron Age and perhaps suggests they were not so different to us ?

We know very little about the character, and perhaps will never know, but we can perhaps paint a story from his discovery.

The character was discovered in a pit dug into the remains of the domestic building, Structure B. Lying to the north and north-west of the main trench, the Structure B complex contains cellular, rectilinear and sub-circular building remnants, with many well-preserved hearths, stone fixtures and fittings, thresholds, wall piers and floors.

This complex, Martin Carruthers from The Archaeology Institute University of the Highlands and Islands explained, was undoubtedly domestic, and produced artefacts consistent with this – substantial amounts of pottery, stone tools, and an extensive animal bone assemblage.

The stone head had been carefully deposited in a pit, along with a number of other artefacts, presumably at the end of the site’s life. We can only guess as to the carving’s purpose – was it intended to portray a spirit or god, or was it merely a cherished possession.

Martin explained: “One recurring aspect of this site is the fact that there’s a whole series of later features that have muddied the waters somewhat.On the one hand we’ve been able to piece together these really intimate details of life within these structures – the domestic artefacts, the metalworking etc, but at the same time the overall shape of some of the buildings remain obscure – obliterated through time and continual reuse.”

Thanks to Sigurd Towrie and the Orkneyjar website. Click here for more information on The Cairns and a link through to Orkneyjar

The excavation was supported by Orkney Islands Council, Orkney College UHI, the Scapa Flow Landscape Partnership, Orkney Research Centre for Archaeology (ORCA) Aberdeen University and Glasgow University. The team would also like to thank the South Ronaldsay community and landowner Charlie Nicholson.

Wrecks of experimental ships discovered in Scapa Flow

Historic Environment Scotland commissioned ORCA and SULA Diving to conduct side scan sonar and archaeological diving surveys in 2015 of two wrecked vessels located off Flotta Island, Orkney, N.Scotland.

The vessels were first brought to the attention of the authors by Hazel Weaver of the MV Valkyrie after they were dived by Rob Baxandall.

Archival research indicates these are the remains of Anti-Torpedo Close Protection Pontoons (ATCPP), an experimental protection device used for close protection of naval vessels at anchor in Scapa Flow from attack by aircraft-launch torpedoes. The pontoons were only in operation in Scapa Flow for 13 months (March 1941 – April 1942) and few were brought into service.

As such they represent a rare, frequently mis-identified heritage resource, for which very little is known about their operation. Had the site not been reported, a unique heritage asset would have been overlooked and the identity of similar vessels would have remained unconfirmed.

Many thanks to Hazel Weaver and Rob Baxandall for their help and co-operation.

Also don`t forget to visit the Secrest of the Sea exhibition in Orkney Museum in Kirkwall if you are in Orkney…..http://wp.me/p6YR8M-f1

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Do Orcadian Tombs Align with Solar Events ?

 

Research conducted by Andrea Boyar BA, Post Graduate student at The Archaeology Institute, University of the Highlands and Islands, Orkney.

Introduction

Orkney forms one of the most intensively studied regions in Britain, providing a ‘core area’ for research (Barclay 2004: 34-37). The aim of this study was to establish to what extent Neolithic cairns in this region align with solar events

Research Objectives

  • Determine the orientation of the entrance passages of the Orcadian chambered cairns.
  • Establish trends within the range of orientations.
  • Analyse the extent of alignments that fall into the range of orientations.

Background Context

The funerary monuments of Neolithic Orkney are characterised by stone-built burial mounds situated near water, perhaps indicative of the importance of sea migration (Phillips 2003: 384). These cairns contained inhumations and cremations reflective of collective burial practices, in addition to an assortment of animal bones, stone tools, pottery, and other grave goods (Davidson and Henshall 1989: 52-59). The monuments appear to have been in use for a few hundred years, and there is a “strong possibility” that many were re-used before being deliberately decommissioned (Lee 2011: 43).

Types of Neolithic Cairns in Orkney

Orkney Carin types

Case Study: Rousay

Rousay orientation.png
Distribution map of the Rousay chambered cairns, showing orientation of entrance passages acording to azimuths measurements

The island of Rousay was selected for a case study due to a high concentration of well-preserved burial architecture. The primary fieldwork aim was to record cairn azimuths in order to measure deviation from solar alignments. Key to this analysis was Stellarium, an open source planetarium used to establish the Sun’s position in the Neolithic period in Britain. By utilising precise measurements, rather than relying upon cardinal point orientations, this approach allowed for a more temporal conclusion to be reached on the relationship between solar alignment and mortuary architecture in the Neolithic.

Project Results

Azimuth results
Azimuth of Rousay Cairns

Orkney-Cromarty cairns were predominantly orientated towards the southeast, with an avoidance of northern orientations

Maes Howe cairns were more variable; there appears to be a shift from the southeast to the southwest, with a complete avoidance of the north

Hybrid cairns were the most random, containing northern orientations within examples of atypical subterranean architecture

Project results

Research Findings

  • Early Neolithic cairns placed an importance on the Midwinter sunrise, while late Neolithic cairns exhibited a shift towards the Midwinter sunset
  • An avoidance of a northern orientation, which would theoretically place a tomb in a state of perpetual darkness
  • The outlier cairns orientated to the north demonstrated atypical subterranean architecture, perhaps indicative that these specific tombs were built to intentionally keep light out of the interior
  • Azimuths provided a temporal range for illumination periods – an area of further research

Further Research

Considering how this study has evidenced seasonal intervals beyond the solstices as significant, it would be worthwhile to look at how times of illumination may relate to periods when Neolithic Orcadians would visit a tomb, inter their dead, and manipulate the remains. Applying the methods utilised in the Rousay case study to the rest of the region may reveal further insight relating to the temporal function of astronomy in Neolithic Orkney.

Conclusion

Neolithic Orcadians were an agrarian society, and as such, the changing seasons would have played an integral role to the sustainability of their way of life. For reasons unknown, solar alignments were incorporated into burial architecture; with a focus on the Solstice period, a time when one cycle ends and another begins. It is possible that sunlight was simply useful for physically seeing inside the chamber itself, however, it appears that these alignments reflect an underlying cosmology indicative of the cultural importance of the sun to an agricultural community. Cairns are mortuary structures, thus the alignments evident within them may reflect pivotal periods in the year associated with ancestral rebirth or renewal

 

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Using Archaeomagnetic Dating at The Ness of Brodgar

A new website has been set up by Sam Harris who is undertaking PhD research into archaeomagnetic dating (this is explained on the website) based on samples he has taken at the Ness of Broadgar. Sam’s research should provide complimentary dates to the C14 ones we have done in conjunction with the Times of Their Lives Project. This will help with the refinement of the chronology of the Ness and also the use of this technique.

The primary aim of this PhD project is to develop archaeomagnetic dating in the Neolithic period in Scotland. This research will expand on the pre-existing chronological dating tools available to the archaeologist by extending the calibration curve for archaeomagnetic dating. This will allow investigations of heated archaeological material from older parts of antiquity than previously permitted. Further afield this will contribute to geophysical understanding of the Earth’s magnetic field in the past. The Ness of Brodgar’s ongoing excavations have allowed a significant amount of sampling and will continue to do so as the PhD progresses.

Already the results are looking very promising!

http://neolithicarchaeomagnetism.weebly.com/

How did the Neolithic Orcadians keep dry ?

 

Research conducted by Neil Ackerman, The University of the Highlands and Islands Archaeology Institute.

Background

This project looked at the roofing flagstones from the Ness of Brodgar. This is the first evidence for Neolithic roofing of this kind on Orkney. Previously, roofs have generally been assumed to be made from organic materials, such as turf or thatch. While stone roofing has been suggested as a potential on a few occasions, this is first time a collapsed flagstone roof has been identified. The majority of flagstones come from Structure 8, providing a detailed sample to study further. This evidence provides a unique opportunity to gain insight into a poorly understood aspect of Neolithic construction.

Structural Understanding

Rebuilt south west wall of structure 12
The rebuilt south west wall of structure 12

Understanding the roof furthers our understanding of the structures as a whole. The internal piers in the building could serve to shorten the unsupported span of the roof frame significantly. It also gives a possible explanation for the failure of the south west wall from Structure 12. The significant outward thrust of a roof of this size could easily cause a collapse like this if not properly countered. The shortening of Structure 1 could also be a response to a roof collapse, with the later wall being built directly on top of the collapsed material. Shortening the structure would provide less of a weight to support.

 Construction and Collapse

The distribution of the flagstones from the roof in Structure 8 hints towards the construction methodology. The size of the flagstones reduces towards the centre of the reconstructed roofstructure, but are smallest at the end wall suggesting the roof follows the curve of the wall.As well as showing the way the roof was built, the distribution of the flagstones also shows how it collapsed. They are not found vertically against the walls as they would likely be if the roof had deteriorated over time. Rather, they are spread across the structure with 89% lying at ≤45°.

Weatherproofing

Large amounts of compact white clay were found with the flagstones when they were excavated. This could serve as a caulking material, as well as keeping the flagstones together. An internal covering is also highly likely, as there is no evidence of direct exposure to the smoke and soot from the internal hearths. A seamer method was used to cover the gaps between flagstones and reduce the amount of moisture getting into the structure.

Suggested Models

By looking at historical use of flagstone in roofing, and evidence from the Neolithic flagstones, three models are suggested:

a) Uncovered flagstone roof

b) Covered flagstone roof

c) Partial flagstone roof