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Archive May 2011

Space Archaeology and the Discovery of Buried Egypt Brigid Gallagher May 28

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Once upon a time archaeology was about being out with a map, a compass, a trowel and a good pair of boots.  Now its ‘Move over Indy’… Space Archaeology is here…the final frontier. 

News reports this week here and here  described how images of lost, undiscovered or misunderstood archaeological sites using NASA satellites, 435 miles above earth, are changing our understanding of ancient Egypt.  By directing an infrared ray and a camera at earth, buried sites, not visible on the surface, come to life for archaeologists to study, governments to administer and security guards to protect.

This is what popular archaeology is all about…exploration and discovery!  I’ll bet this is what many archaeologists born in the 70’s grew up believing in. 

1.  21st century technology,

2.  The ability to dig and understand archaeology without actually digging it,

3.  Pointing lasers or some other imaging ray at the earth to reveal intricate details of past inhabitants, and

4.  Egypt…the Queen of the archaeological world! I am envious!

To cover it succinctly, the main points of the story are:

  • That 17 new pyramids and 3,000 new sites have been identified by infrared technology, captured from satellites. 
  • That 1,000 tombs have been identified.
  • That infra red cameras can detect and record objects or features less  than a metre in size.
  • That we now have the technology to accurately identify and map buried archaeological settlements, across large areas.
  • That we now have the technology to monitor, assess and protect archaeology from space, with high precision.

By detecting differential changes in material densities and heat stored within buried archaeological features, and comparing that with the background response of surrounding natural sediments or geology; the footprints or outline of archaeology no longer visible in the modern landscape can be seen.

For example, the hard mudbrick that Egyptian houses were normally constructed from, give a different signal or response to the loose desert sand sediments surrounding it.

The result is that Dr Sarah Parcak of the University of Alabama and NASA are changing the historical concept of settlement, and burial practises, in Egypt. Large areas of land can be investigated using satellite remote sensing, allowing archaeologists to get a better sense of spatial distribution, size, scale, complexity… and discover unknown sites.  

The infrared images are able to detect those remains in the first metres of the earth’s surface, in areas where there is no modern development.  Parcak suggests that there may be more sites and monuments at deeper levels still unknown. 

As an old fashioned field archaeologist, I am very heartened to read that she believes follow up fieldwork and excavation to confirm these initial findings is essential…this enables site characterisation and mean the images undergo rigorous testing regarding their value in archaeological and heritage investigation and management.  This could make a huge impact on the way sites, particularly those in isolated locations, are cared for and protected.

The BBC followed Parcak to Egypt for a documentary, Egypt’s Lost Cities, due to air this Monday in the UK, to test the amazing network of buildings and streets recorded of the ancient city of Tanis. 

The Ancient City of Tanis

A satellite image of an area of Tanis that shows the city to be littered with underground tombs. An ancient streetmap: A satellite image shows a densely occupied city.  Buildings in ancient Egypt were constructed out of mud brick – the material is dense, allowing satellites orbiting above Earth to photograph the outlines of structures invisible to the human eye.
Hidden history: This image of Tanis shows the difference between what the naked eye can see and the underground details that the high-powered satellite camera can pick up

Modern city San El Hagar on the left, with the inset showing the location of ancient Tanis.

Although I have not seen the documentary, news reports described this as a nervous journey, with the team focusing on one target identified by satellite.  The result was the excavation of a 3,000 year building, that matches the shape seen on the satellite image.  Fantastic! 

A Pyramid Complex

Just as amazing is the image of the previously undiscovered pyramid complex.  In the image, 3 square monuments are clearly visible, all of which clearly have circular void spaces internally.  Are these the burial chambers? 

 Saqqara satellite shot

The pyramids are surrounded by boundary ‘walls’ with access points across them, auxiliary buildings, and chevron shapes pointing inward toward the pyramids.   The remains of ramps used in construction or another purpose? 

Outside the immediate pyramid complex are small circular crater like features, and any number of dark points.   Perhaps these are underground tombs and secondary burials, or are they small mud brick dwellings?  Perhaps the evidence of workers and associates also killed on the death of the person inside the pyramid. 

It is tantalising, albeit romantic, archaeology at its best

Of course this is not really new, satellites and radar technology were used by Damian Evans and Bill Saturno from the University of Sydney to visualise the Angkor Wat complex in 2008 from 200 miles in the air see here, and New Zealand archaeologist Kevin Jones flagged the use of infrared technology as potentially benefiting the understanding of Pa and horticultural landscapes in New Zealand in his 1996 article ‘Aerial Photography in New Zealand Archaeology’, see here.

Angkor Wat, Cambodia

A satellite image of  The temple of Angkor Wat from above–the surrounding ruins hold untouched archaeological treasure. Image: NASA, Stephen Studd/Getty

 

The question has to be asked?  Could a landscape such as New Zealand benefit from such a survey?  We have large unpopulated spaces, but would our wet, temperate environment and variable topography muddy the results.  I ask this in regard an article released on April 27th this year in the Wanganui Chronicle announcing the discovery of 720 new historic and archaeological sites in the Wanganui District.  One of the sources of the discoveries was the 1942 run of aerial photography.  Does satellite imagery have the potential to simplify this process of identification and management in New Zealand? Or does it open up sites to potential mismanagement through lack of funds and protection when dealing with increased numbers of archaeological sites?

Aside from the practicalities of its application, if you put together the images generated from this recent story with the words Space, NASA, Indiana Jones and Egypt…and you get a powerhouse story that is sexy, techy and looks good…its probably a good lesson in how archaeology should be advertising itself.

It is just a pity all archaeologists don’t have a space rocket parked in their garage!

Big Dig Archaeology Brigid Gallagher May 15

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One of my pet subjects is public or community archaeology. Not surprising given my years with Time Team, so…

This week is National Archaeology week in Australia! Ok, so it is not New Zealand, but the event that has taken my eye, and is happening this weekend, right now….it is the BIG DIG.

Located in Sydney’s The Rock’s district, in a partnership between the YHA and the Sydney Harbour Foreshore Authority, the Big Dig Archaeology Education Centre is a massive educational and excavation undertaking. It is described on its website as

          ‘the largest archaeological urban development ever completed in Australia. It demonstrates that the conservation of in-situ remains as part of a modern building can enhance visitor experiences and interest, as well as preserving sometimes fragile archaeological remains in an accessible and meaningful way.’

What have they found?   Or perhaps, why is this excavation important to conserve or preserve? ·

  • In 1994 excavations began in an area that is located between Gloucester and Cumberland Streets in the Rocks.
  • The initial excavation was a big salute to public/community archaeology with 400 volunteers and 20 archaeologists involved. ·
  • The result is the ongoing excavation of foundations from over 30 homes and shops, the earliest built in around 1795, and some 750,000 artefacts. It represents some of the earliest European settlement in Australia.

Is it Important?

This is a very rare opportunity to continuously dig and research the information gathered from a site, AND because of the later introduction of the education center, set within the YHA, is able to promote and inspire future archaeologists and heritage professionals. Because the site is in one of Sydney’s tourist areas, it increases the visibility and social relevance of the site as more public and tourists visit.

Is this Important?

Absolutely. One of the key attributes very often overlooked by professionals…not generally because of intent, but perhaps forgetfulness…is that archaeology is incredibly tactile and emotive.

Like many experiences and memories that are lasting; it is the touch, the smell, the taste, the feeling that impacts greatest. Archaeology is the same. The process of excavation or digging is incredibly tactile.

Feelings described by volunteers on a site, or a new archaeologist fresh into the field, are often raw and emotive. People feel something for the past by the process of feeling it. It’s tactility. The sense you are revealing the past for the ‘very first time’.

Theoretically, if you bring people to a site, help them to feel part of the site and its history, the more they will go on to respect, care and conserve artefacts, sites, archaeology, history…themselves.

This experience of archaeology is becoming increasingly significant to society.

In parts of the UK, there have been huge successes in bringing juvenile offenders to archaeological sites, such as in the city of York. By physically getting them down on all fours with a trowel in hand to excavate, with a nervousness or uncertainty which naturally comes with revealing or finding something that is considered ancient….seems to bring out humility and respect.

It fits in well with the ‘getting back to nature’ attitude and concept of ‘gardening therapy’ which psychologists recommend to clients. The act of cleaning back dirt is distinctly therapeutic.

In my experience of all 3 Big Digs that Time Team UK has created including; ·

  • The Big Dig (test pitting all over the UK, working with people in their back yards to reveal the past, culminating in a huge community excavation on a Roman site in Swindon) ·
  • The Big Roman Dig (Visiting and participating in excavations on Roman sites from all over the country in 8 days to tell the story of the Roman occupation, with a constant ‘main’ site excavation running through the whole period at a Villa site in Dinnington, Somerset) ·
  • The Big Royal Dig (A 4 day event in 3 royal locations, Buckingham Palace, Windsor Palace and Holyrod, Scotland, to piece together changes in landscape, use and architecture over time).

 These Live events (and as far as I know, not shown here in NZ) have seen large numbers of volunteers, locals, young and old, professionals, specialists and celebrities come together to bring archaeology to the British public…as it happens. They have been a successful exercise in terms of public or community archaeology.  It has been inspiring for me as a professional to watch the enthusiasm of the public, adults and children.

Back to Sydney’s Big Dig…I love it!

          1. Bring together a whole bunch of people who are passionate about archaeology and the past.

          2. Add some people that speak with passion, clarity and knowledge about the findings.

          3. Add a lot of dirt, a quantity of artefacts and structures, a GPS total station, a digital camera, a note book or context sheets for recording.

          4. Combine a few planners/illustrators, a surveyor, a photographer and a whole lot of field archaeologists/excavators/diggers.

          5. Set up some artefacts specialists, historians, computer imaging gurus, other relevant brain boxes.

          6. Put in some conservation/preservation experts, analytical specialists, communicators and educators.

          7. Underpin it all with good theory, best professional practise and guidelines.

What have you got?

1. Inspired, interested and caring society

2. Fantastic syntheisis of specialists and experts

3. Site preservation and dissemination

4. Widespread media release and social relevance

5. Education to all With the Potential of Economic Return!

LOVING IT! This is Science on the Cutting Edge.

1. Be accountable,

2. Be visible,

3. Deliver.

Working with Stone, Connecting with the Past Brigid Gallagher May 05

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I love rocks.  The different planes of fracture, colours, inclusions, textures, strength…and sometimes fragility…optical properties, the way they feel in your hands….

What I also love about rocks is that they can be made into the most fantastic  stone tools, or as Simon Holdaway insists in his recent interview with Graeme Hill, artefacts. 

One of the beauties of this is that different stone types lend themselves to different tool or artefact forms, and different functions. 

A joy of this is that when you pick up a stone artefact such as a Palaeolithic hand axe or side scraper, a Mesolithic microlith, a New Zealand prehistoric adze or toki, or an obsidian blade; you can literally feel the way in which it is supposed to sit in your hand, or in a shaft. 

Even in prehistory our ancestors appear to have placed importance on ergonomic design. It is important to remembered that stone tools were literally the equivalent of our metal tools today.  They would have been used in many domestic and ‘industrial’ settings of the past…and they would need to be comfortable to use! 

In the Hill interview, the types of rocks used to bring about the design, or form as it is known in archaeology, is discussed. 

          New Zealand greywacke and argillite are fine grained, relatively homogenous and strong, whilst obsidian (which is technically a glass) is fine grained, homogenous, but brittle. 

Obsidian, when flaked, produces a blade which holds a very sharp edge, and can be used as a knife.  However, in the use of this cutting edge, the blade very quickly dulls and is liable to break depending on the force imposed on it. 

 More typical rocks seen in prehistoric adze manufacture sites in New Zealand are greywacke and argillite, which produce a ‘blunter’ edge.  However they can be hafted and used much like an axe would be today; to withstand hammer like blows, again and again.

Other rocks not touched on in the Hill interview, but used in the New Zealand stone artefact industry include,

           Greenstone or Pounamu; which is dense and strong, but again due to its crystalline structure…once its zone of weakness has been found, it will break quickly and cleanly. 

           Chert or flint, used in hand axe, microlith and drill point manufacture for instance is excellent, but with force breaks along the cutting edge. The form of the desired tool also contributes greatly to the success or failure of these tools. 

          Like argillite and greywacke these two rock types are fine grained and fairly homogenous.

What is the difference between them at a practical, tool making level?

Which stone is able to be worked in what way, and allows the person working the stone to control it during tool or artefact manufacture?

New Zealand pounamu or nephrite is rated about 6 on the Mohs scale of mineral hardness (diamond is the hardest at 10).  It is also considered very tough, and fractures conchoidally.

          But, on a practical level, when making a pounamu artefact, the density, toughness and lack of controllability during flaking makes it a difficult to work.

Because of the physical properties of pounamu, it is best, or easiest, to grind and polish the tool or artefact.  The little control over the stone during flaking, makes breakage likely. Though there are examples of flaked pounamu tools in New Zealand, such as at Oruarangi in the Hauraki. 

The end result is that while a ground and polished pounamu artefact looks beautiful, and can be used to create large artefacts, it has consumed many hours of energy.  As a result, artefacts of pounamu are interpreted as ceremonial…which contributes to its ‘specialness’. 

An interesting aside to this that I like having witnessed many examples when I worked at the Auckland Museum, is when pounamu adzes break in the making.  Instead of being able to quickly turn out a modified artefact, the original tool may be turned into a completely new artefact, such is the desire not to waste the stone   This is often evident in the hei tiki.  Along the base edge of many historic and prehistoric tiki examples, a short bevelled edge can be seen, where the pounamu was originally intended as an adze.  It broke in the making, and was changed from a adze perform to a hei tiki.

Chert or flint on the other hand have a hardness factor of about 7, but because of its physical properties, flaking is possible, and fracturing easier to control by the maker.

          A hammerstone can be used to knap or flake the core of the rock, and  because of the density, toughness and controllability of the stone, the manufacturer can achieve a finished tool this way. 

Flaking or knapping is a very satisfying process due to the precision of the blows, but there is also an immediacy in the way things happen.  Strike after strike, flakes or debautage is removed.

Chert and flint artefacts can be quickly and efficiently made, depending on the skill of the knapper.  If the tool breaks during manufacture, the stone can often be speedily modified, to produce a new tool.  Because of this property, it is a stone that is often well represented on archaeological sites as it makes up a large quantity every day ‘prehistoric’ tools used in everyday tasks…all over the world.

New Zealand’s Nelson-Marlborough Argillite, Greywackes and Basalts (namely Tahunga) have a hardness factor of about 6.5-7, and whilst technically heterogeneous, are recognised as one of New Zealand’s best sources for stone tool material through out prehistory.  Argillite in particular has the capability to produce beautiful, high polished, large adzes, with excellent working properties.  See this article in the Manawatu Standard regarding a large argillite adze find in Porirua recently.

Often used in New Zealand adze manufacture a combination of grinding/polishing and flaking techniques are used, with an added pecking or hammerdressing stage.

  1. the basic form of the adze is flaked or knapped from a core with the use of hammerstones,
  2. once this is achieved the major protuberances are pecked or hammerdressed to remove them with the use of smaller, harder, hammerstones,
  3. in the final stage, grinding and polishing is conducted to finish the tool. 

In my experience of making a small greywacke adze or toki while I was studying at Auckland University, the final stage is the most time consuming part of the process.  Using sandstone grinders, or hoangas, of varying roughness, the bevel and the cutting edge are formed, and then polished.  My result was small but excellent.  It took 2 days to create from a split Motutapu Island greywacke cobble.  Under the guide of Dante Bonica, part of the Maori Studies Dept at Auckland Museum, I used traditional methods in its manufacture…and at the end Dante hafted my c.12cm 2B adze, and cut down a small tree.  Amazing!

A Method of Connecting with the Past

I want to finish this blog on an aspect of the Hill interview that I found really interesting and supports science as a discipline based on evidence.

The interview ended with Hill and Holdaways Masters student, Kane, agreeing that by witnessing and participating in the manufacture of ancient tools using traditional techniques you could feel a connection for the past. 

Graeme felt it was about a connection with past artisans and cultures.

Kane felt a connection with the past by replicating techniques, but admitted that he was thinking about it scientifically rather than contextually.

How can this be?

Through the process of experimental archaeology, archaeologists can attempt to quantify information they are collecting through a trial and error process.  Evidence is collected from the debris or debautage collecting around the knapper, the core from which the artefact is produced, the time taken to produce the artefact, the best position the stone was held and the knapper was sitting or the ability to used the tool or artefact.

The Hill interview tells us that the angle at which the stone core is struck is important and understanding the physical properties of the stone being worked are important.  These relate to the cold hard facts of rock science, and are intrinsic in this reporters belief to the final form of the artefact or tool produced.

But I often wonder in experimental archaeological exercises how the brain is able to focus to such an extent that the artefact is viewed clinically, as a series of molecules, fracture planes and physical properties for example, rather than the image of a rock as our eyes sees it. 

Did all people in the past see the tools or artefacts in this way?

I don’t know, but it is my opinion that the context and the pure artistry of the maker should not be under-estimated… and it is very probable that Graeme’s past artisan was is in fact using science…but did not know the right words for it!

References:

          Marianne Turner  2000  The function, design and distribution of New Zealand Adzes, submitted in fulfilment of PhD Thesis, Auckland University. Online.

Please note…I have not got into the intricacies and differences between chert and flint, as this is still of some debate in science circles, also, this is not meant to be a full and complete summation of rocks and their uses in NZ…And apologies for the lack of photos…

Stone Tool Artefacts & Simon Holdaway on Graeme Hill Show, May 1 Brigid Gallagher May 01

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I just wanted to get this out there before Graeme Hills Radio Live  show tomorrow/today, May 1.  At 11.30 am Graeme is going to be speaking with Professor Holdaway of Auckland Universities Anthropology Dept.  They will be talking stone tools, and the segment is titled ‘Rare and Ancient Trades’.

I don’t know where the conversation is going to lead, but Holdaway was featured in the Herald last year due his research in Egypt on stone artefacts, which is part of a larger project lead from UCLA and Rijksuniversiteit, Groningen.  He also directs the Western New South Wales Archaeological Project (WNSWAP) with Patricia Fanning of Macquarie University.  The description on the WNSWAP website is;

The projects use the latest electronic survey equipment, GIS, and database software to map, document and analyse the distribution of Aboriginal stone artefacts and associated heat-retainer hearths in their landscape context. They are supported by an intensive program of dating, using the charcoal and hearthstones from heat retainer hearths and sediments within valley fill sequences, to provide a chronology of landscape change and Aboriginal settlement.

Whatever the angle I am sure it will be interesting, and I hope that somewhere they get a chance to talk about New Zealands fascinating stone tool technologies and presence in the archaeological record.  Next week I will post the audio file, along with an associated blog.

Apologies for the late notice…our house is a hot bed of various lergies and complaints…

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