Tag Archives: Maritime Archaeology

Quantitative analysis of glass artifacts from marine environments using pXRF.

Posted on June 18, 2017 by Lily Rogers | 1 comment

By Lily Rogers, Master of Maritime Archaeology student

This blog will explore a key issue relating to quantitative analysis of glass samples from marine contexts using pXRF. The purpose of quantitative analysis is to produce data relating to the exact relative quantities of major, minor and trace elements in glass samples (Shackley 2011:220). In relation to the analysis of historic glass, quantitative analysis is much more difficult than qualitative analysis and there are a range of factors that influence the accuracy of data produced (see Kaiser for an overview of these). These issues can be separated into two broad categories. The first relates to the limitations of the particular instrument used (this will not be discussed here) and the second relates to the condition of the glass samples themselves (Liu et al. 2012:2129).

Historic glass experiences surface alkali depletion due to weathering processes  and this will affect the accuracy of quantitative data (Kaiser and Shugar 2012). This is because pXRF is a surface analysis technique and processes such as weathering mean that tests on the surface of the glass are likely not to provide data that is representative of the bulk composition.  Liu et al. (2012), in their study of glass beads from archaeological sites across Xianjing, China, analysed the effects of unpolished surfaces in comparison to polished surfaces on pXRF analyses. Polishing involves removing a small portion of the weathered surface of the glass. Their study showed that analysis of weathered (unpolished) surfaces affected the accuracy of compositional data in terms of the quantities of all elements detected (Liu et al. 2012:2132). This study also showed that polishing a small area of the surface to remove the weathering increased the accuracy of the measurements.

Reference List

Liu, S. Q. H. Li, F. Gan, P. Zhang and J.W Lankton 2012 Silk road glass Xianjing, China: chemical compositional analysis and interpretation using a high-resolution portable XRF spectrometer. Journal of Archaeological Science 39:2128-2142.

Shackley S. 2011 X-Ray Fluorescence Spectrometry (XRF) in Geoarchaeology. New York: Springer.

 

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Introduction to PXRF Analysis of Glass Artefacts from the Marine Environment

Posted on June 8, 2017 by Lily Rogers | 1 comment

By Lily Rogers, Master of Maritime Archaeology student

This semester I’ve been doing a Directed Study project as a part of my Masters in Maritime Archaeology.  I am doing my project at the Maritime Archaeology Department, based at the Western Australia Shipwreck Museum, and my person of contact is Assistant Curator Debra Shefi. My task is to produce a literature review on the potential for determining the provenance of glass from underwater shipwreck sites by determining its elemental composition using portable X-ray Fluorescence (pXRF) spectrometry. This is the first step in a larger project developed by Deb.

The development of pXRF technology is especially valuable in museum contexts as it allows for non-destructive analysis of artefacts. While this is one of the greatest benefits, it also poses one of the greatest problems for studying historic glass. This is because archaeological materials such as glass often have uneven surfaces, thicknesses and composition, as well as having undergone corrosion and leaching processes. pXRF is a surface sampling technique and the accuracy of the data it can produce is affected by all of these factors. The marine environment has an effect on the glass through corrosion (removing the surface of the glass) and leaching (removing chemical components of the glass). While there are many studies that deal with historic glass and pXRF in terrestrial contexts, a key aim of my literature review is to attempt to locate any research that deals with pXRF analysis on glass in the marine environment.

For more information on pXRF analysis of historic glass see:

 http://inter-s.com/learnxrf/category/xrf-principles/

https://www.bruker.com/fileadmin/user_upload/8-PDF-Docs/X-rayDiffraction_ElementalAnalysis/HH-XRF/LabReports/Bruce_Kaiser_poster.pdf

https://www.academia.edu/6272096/_2012_Glass_analysis_utilizing_handheld_X-ray_fluorescence_Kaiser_and_Shugar_

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Commissioner: An Undiscovered Shipwreck

Posted on November 14, 2016 by Cameron Mackay | Comments Off on Commissioner: An Undiscovered Shipwreck

By Cameron Mackay, Graduate Diploma in Maritime Archaeology student

Over the last few months I have been busy working and developing my methodology, which I have shared with you, and have managed to generate my results for Heritage Victoria. So obviously this will be my last blog post.

I have decided to use this blog to discuss one more vessel.

Introducing Commissioner: an early torpedo boat that was built for war to protect Australia.

captureA torpedo boat is a small vessel that is designed for speed and to carry ordnance into battle to be deployed before retreating. Australia had a very limited arsenal of torpedo boats, especially in Victoria.

Commissioner was built in 1878 and was  one of the first torpedo boats capable of firing a Whitehead torpedo in Australia. The Whitehead torpedo was one of the first self-propelled torpedoes. Some of the activities that Commissioner took part in were night patrols and dealing with pirates. The vessel eventually sunk in 1914 while being towed from Melbourne to Sydney for a refit, due to extensive use having left the vessel in poor shape.

This ship forms one of my top 20 because of its historic nature and social connection to Australia through its role of protection. The vessel was also rare in design, with only five other torpedo boats having existed in Victoria. The report of its sinking also suggests that the vessel may still be somewhat intact if discovered, which would provide insight into its construction style.

I would like to thank Heritage Victoria for the opportunity that was provided to me. Special thanks go to everyone in the Maritime department who guided me through the development of significance and answered all my inquiries around the database.

Some of the skills I have taken from my time with Heritage Victoria include developing my database work, writing skills, organisation of data and research skills.

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Victoria’s Most Wanted

Posted on September 13, 2016 by Cameron Mackay | Comments Off on Victoria’s Most Wanted

By Cameron Mackay, Graduate Diploma in Maritime Archaeology

As stated previously, I am creating a list of Victoria’s top 20 undiscovered shipwrecks. This is the second instalment of my four-part blog series. In the previous instalment I addressed significance and the role it plays within archaeology and cultural heritage.

This time I shall focus on the main aims of the project and how significance values have been used in developing the list. The intention of the list is to direct the limited resources of both Heritage Victoria and interested community groups, such as the Maritime Archaeology Association of Victoria ( MAAV), to research the sites that have potential to contribute most to the understanding of Victoria’s maritime heritage.

The MAAV is an active group of divers, historians and archaeologists who research, survey and promote maritime history and archaeology. It is hoped that producing a list of the State’s “Most Wanted” wrecks will provide a focus for community engagement with Victoria’s most significant shipwrecks.

Since my previous post I have modified my methodology. Instead of including the requirement that all sites in the list meet at least one significance criterion, I have increased the number of criteria that need to be met to a minimum of six. This has enabled me to quickly reduce the total number of sites being examined from 450 to 60 of the most potentially significant sites. This approach has also allowed me to continue to work within the project’s tight time frame.

From this first, fairly coarse, ranking system I have attempted to develop a more nuanced ranking within each defined significance criterion. The intention of the ranking is to filter the remaining 60 sites in the most objective way. My method has been to identify a number of subcategories under each of the main significance headings and assign each a value of between one and five, based on defined definitions addressing each value, thus providing a possible maximum score of 105 overall from the seven significance categories. The final score is multiplied by a factor of 0.9524 to reduce the score to a percentage (value out of 100). When it comes to examining the 60 sites this value of 100 will assist in providing an overall ranking and a degree of separation between wrecks to create a list of the top 20.

It is important to note that, while my method attempts to provide an objective measure of significance by assigning values to subcategories within each significance criterion, the value assigned to each will still ultimately depend on the person assessing the information available for each wreck.

It’s also important to note that, for a list of the top 20 most wanted wrecks, significance will not be the only factor that needs to be considered. Other factors will also need to be taken into account to generate the final “Most Wanted” list. Some of these are:

  • Mystery;
  • Environment; and
  • External Interest.

Mystery is a factor that should be considered, as there will be more public interest in a ship that may have been carrying gold or that mysteriously disappeared, or that we know little about. The environment is another factor: a vessel that is recorded as being buried under large amounts of sediments or existing in a high energy environment will be more difficult to record than one that sits in a low energy environment. Finally, external interest from other parties should be considered in case research is already being focused on certain wrecks, or an industry has formed in relation to the shipwreck that may increase its importance or the interest that is generated around it. An example is the Curlip shipwreck. The Curlip has had a cruise industry built in memory of the ship, in addition to a replica vessel, Curlip II, due to the importance it had in the local area.

curlip-ii

The Paddle Steamer Curlip II at sunset on the Snowy River. http://www.abc.net.au/local/videos/2008/11/28/2431977.htm accessed 8/9/16

If the site was discovered it could possibly generate interest and media, while also providing support for the Curlip II; this means that the importance of the site could be increased.

http://www.paddlesteamercurlip.com.au/

http://home.vicnet.net.au/~maav/

http://www.abc.net.au/local/videos/2008/11/28/2431977.htm

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Establishing significant shipwrecks in Victoria

Posted on August 21, 2016 by Cameron Mackay | 1 comment

By Cameron Mackay, Graduate Diploma in Maritime Archaeology

This is the first of four blogs to be written in conjunction with my directed studies research topic taken with Heritage Victoria.

The main aim of the research is to create a list of the top 20 undiscovered shipwrecks within Victoria by using significance criteria to prioritise sites within the Victorian Heritage Database (VHD).  The sites prioritised will be those that can yield the most public interest, contribute to Australia’s cultural/local area history and establish possibilities for further understanding of shipbuilding and experimental building techniques.

The question also arises as to what wreck remains will still exist at the sites and what these remains could reveal, in addition to what cargo may have survived.  These questions are to be addressed later in the research, however, and will be an underlying factor throughout the research.

As the research is focused on the idea of significance it is important to understand what that actually means to begin with.

Significance

“the quality of being significant or having a meaning.”

Macquarie Dictionary. 2016. [Online]

Significance in the context of archaeology is difficult to define with absolute certainty, and is subject to change. This is due to the changing information, opinions and requirements individuals may have at any time, which changes the meaning of significance.  As such, significance may be defined as a fluid, ever-changing idea that is based on changing individual views, beliefs, opinions, needs and objectives. It is important to note that significance must be constantly reviewed, revisited and checked.

Significance plays an important role in archaeology, particularly in assessing cultural heritage, in terms of the creation of criteria to assess sites and establish values in different areas. With its fluctuating meanings, however,  significance criteria to assess sites and establish values must be reviewed constantly to ensure that all aims and objectives are being met. Such review also ensures that the significance stays relevant to the research being conducted.

In assessing significance, my project is influenced by the works of:

  • NSW Environment and Heritage: Evaluate the significance of shipwrecks (2012)
  • Victoria State Government Department of Environment, Land, Water and Planning: Criteria for assessing cultural heritage significance (2015)
  • MacLeod, Harvey: Management of Historic Shipwrecks Through a Combination of Significance and Conservation Assessments (2014)
  • Russel, Winkworth: Significance 2.0, A guide to Assessing the Significance of Collections
  • Marquis- Kyle, Walker: The Illustrated Burra Charter. Good Practice for Heritage Places.

These sources use significance criteria in order to prioritise or rank sites to establish significance. This methodology will form the foundation of my research and assist in forming a path for the research to travel.

These assessments all use a similar process, beginning with researching the history of sites for information. This information is then assessed against a defined set of criteria, and expressed as a statement of significance.

For my project, instead of writing a statement of significance, I will use the defined set of criteria to rank sites. This will allow me to establish a list of the top 20, while removing as much subjectivity as possible through a grading system.

A major issue will be combing through the VHD, and correctly being able to research and place sites against each criterion, while reducing subjectivity. This is so that no site is overlooked and all steps in a site’s ranking are clear and logical.

Criteria are fundamentally the same across all significance assessments. I have been able to form a set of basic criteria to begin with, which will be reviewed and refined at a later date. My criteria list is:

  1. Historic
  2. Technical
  3. Social
  4. Archaeological
  5. Scientific
  6. Interpretative
  7. Rarity
  8. Representativeness

As a note, for a site to be deemed significant it isn’t required to meet all criteria, but only needs to meet a minimum of one.

It is this basic list which the HVD will be placed against, to begin forming a significance list. This criteria will be revised and refined at a later date in order to create a ranking system and create a top 20 shipwrecks list for Victoria.

References

NSW Environment and Heritage 2012 Evaluate the Significance of Shipwrecks. Retrieved 10 August 2016 from

Victoria State Government Department of Environment, Land, Water and Planning 2015 Criteria for Assessing Cultural Heritage Significance. Retrieved 10 August 2016 from

MacLeod, I. and P. Harvey 2014 Management of historic shipwrecks through a combination of significance and conservation assessments. Conservation and Management of Archaeological Sites 16(3):245-267.

Russell, R and K. Winkworth 2009 Significance 2.0. A Guide to Assessing the Significance of Collections. Adelaide: Collections Council of Australia.

Marquis-Kyle, P. and M. Walker 2004 The Illustrated Burra Charter. Good Practice for Heritage Places. Melbourne: Australia ICOMOS.

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Maritime Archaeology in the South China Sea Dispute

Posted on December 21, 2015 by cplooram | Comments Off on Maritime Archaeology in the South China Sea Dispute

“What am I getting myself into?” This is a question I ask myself every time I see another headline about tension in the South China Sea (or the East Sea to the Vietnamese). I want to be a maritime archaeologist in Vietnam, one of the seven states vying for control of this sea. Though all are signatories of the United Nations Convention on the Law of the Sea (UNCLOS), which has provisions for establishing maritime territories, China has asserted that their historical rights over the South China Sea override UNCLOS (even though the Convention actually has a clause that prohibits using historical rights as an argument). China has claimed that they have sovereignty over the entirety of the sea within the “nine-dash line” that they base on a variety of historical documents.

Territorial disputes in the South China Sea

In recent years, China has developed maritime archaeology in part to further their claims. The head of the Chinese Centre of Underwater Cultural Heritage reportedly explained that they “want to find more evidence that can prove Chinese people went there and lived there [the islands in the South China Sea], historical evidence that can help prove China is the sovereign owner of the South China Sea” (Page 2013). Since then, other countries involved in the South China Sea conflict have developed maritime archaeology programs, though they have not made their agenda quite as explicit as the Chinese have. The Vice Minister of Culture has even said “marine archaeology is an exercise that demonstrates national sovereignty” (Page 2013).

There are two ways in which underwater cultural heritage can be politicized in the region: the first is to use it as evidence for territorial claims, the alternative is to emphasize the multicultural nature of a busy sea and perhaps promote cooperation. Many political scientists believe that empathy is one way to mitigate tensions, empathy that is built through building trust in order for all parties to understand the others’ worldview (Manicom 2014). On of the ways to build this kind of trust is to collaborate. So far, China has refused to play with others in matters of maritime archaeology.

When a Filipino-French group was researching a Chinese junk in the Scarborough Shoal, they were kicked out by the Chinese military. The head of the Chinese Centre of Underwater Cultural Heritage later explained that they had to be kicked out because “they wanted to destroy evidence that was beneficial to China” (Page 2013). Southeast Asian countries have however collaborated on many projects, as evidenced by the recent field school organized by the Vietnam Maritime Archaeology Project, which I talked about in my last blog post.

The VUAT participants from 12 countries including Cambodia, Indonesia, Thailand, the Philippines, and Vietnam.

The VUAT participants from 12 countries including Cambodia, Indonesia, Thailand, the Philippines, and Vietnam.

I don’t think underwater cultural heritage will be the deciding factor in these territorial claims. For one thing, even ignoring the fact that UNCLOS doesn’t accept “historical rights,” shipwrecks cannot prove ownership or sovereignty. If a country was able to prove that their people had occupied the islands over a significant period of time, they may be able but claim ownership, but a shipwreck does not prove occupation. All the wrecked vessels in the South China Sea show is that it was a busy and dangerous trade route. Regardless, underwater cultural heritage will be in play for the foreseeable future, and as an archaeologist who works in the region it is something I need to be aware of.

I often wonder not only how will I be able to conduct research in Vietnam but also how will my research be used? I think it is important for maritime archaeologists to get involved in the South China Sea (carefully!) before information and sites are lost. The potential consequences of China’s political agenda regarding underwater cultural heritage are a reason for concern alone: it is very likely that they will start favoring sites that promote their current claims, excluding certain researchers because of nationality, or provide limited dissemination of information.

 

References:

Manicom, James. 2014 ‘Empathy: The Missing Link Between Confidence and Trust East Asia.” In Perspective on the South China Sea: Diplomatic Legal and Security Dimensions of the Dispute, 1st ed. 96-103. Center for Strategic & International Studies: Washington D.C.

Page, Jeremy. 2013 ‘Chinese Territorial Strife Hits Archaeology.” Wall Street Journal 2 December

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Three shipwrecks for the register!: DEWNR Southeast Coast Shipwreck Survey, SA

Posted on December 4, 2014 by | Comments Off on Three shipwrecks for the register!: DEWNR Southeast Coast Shipwreck Survey, SA

Date: 27 November–­4 December 2014

Staff/Volunteers: Amer Khan (DEWNR); Simon Carter (DEWNR); Guy Williams (DEWNR); Anthony Virag (DEWNR); Dr Brad Duncan (NSW Office of Environment and Heritage); Kurt Bennett (Flinders University Volunteer); Daniel Petraccaro (Flinders University Volunteer) and David Hanna (DEWNR).

Amer Khan, SA state maritime heritage officer presenting the project to the Carpenter Rocks community. Courtesy of Anthony Virag.

Figure 1. Amer Khan, SA state maritime heritage officer presenting the project to the Carpenter Rocks community. Courtesy of Anthony Virag.

On Monday 1 December, the Carpenter Rocks community hall hosted Amer Khan who gave a talk about the Southeast Shipwreck Survey Project (Figure 1). A number of the local community turned out for the presentation and later shared their knowledge about the area. This provided Amer with new leads, which will hopefully warrant further investigations along the southeast coast. Brad Duncan also gave a presentation on the William Salthouse archaeology project in Victoria. This demonstrated to the community what maritime archaeologists actually do and how unlawful salvage damages everyone’s cultural heritage. When shown pictures of destruction caused by relic hunters, many shook their heads in disbelief. Both presentations were well received by the attendees.

The research team revisited Pisces Star on Tuesday 2 December. Kurt prepared himself for snorkeling out to the shipwreck to assess the condition of the vessel. Due to the currents surrounding the vessel, the snorkeler was tethered to a divers assistant onshore (Figures 2 and 3). Using an offset method from a shore based datum, the onshore team recorded three points marking the stern, midships and bow section. Pisces Star, although shipwrecked in 1997, will be registered on the South Australian shipwreck database and information made accessible for future research.

Next, the team surveyed an area northwest of Pisces Star, where a local abalone diver reported ship timbers. A swim line search consisting of five snorkelers, spreading 25m, covered an area of 150m to search for the timbers (Figures 4 and 5). No one located the reported timbers, but snorkelers observed five iron poles measuring 1m in length. Whilst the poles are cultural, they could not be linked to a shipwreck in the area. Carl and Gary von Stanke, local shipwreck enthusiasts, joined the team for the snorkel and shared their knowledge and history of the local shipwrecks.

Kurt Bennett, Carl von Stanke and Daniel Petraccaro recording Erie. Courtesy of Brad Duncan.

Figure 6. Kurt Bennett, Carl von Stanke and Daniel Petraccaro recording Erie. Courtesy of Brad Duncan.

Erie, the last vessel recorded on this expedition, is a 1940 clinker built transport vessel located at the north end of Lake Bonny in Canunda National Park. The survey team recorded the port (left) side of Erie measuring 5.25m in length. Unfortunately, the vessel was damaged by recent vandal activity where the port side had been pushed over and the keel snapped. Daniel, Kurt and Carl recorded the stem and planking using the baseline offset method (Figure 6).  In the short video below, Amer Khan talks about the construction and features of the vessel (*note—audio is quiet, it is recommended to turn up your volume).

 

On Wednesday 3 December, the survey team followed a lead of a possible shipwreck located in Cape Douglas. The site consisted of two timber posts, 4.25m apart. Daniel and Anthony excavated a 1m by 1m square trench around one of the posts to see if it was connected to other covered timbers (Figures 7 and 8). No other timbers were uncovered and concluded the posts were likely part of a slipway, jetty or fencing.

The project finished on Thursday 4 December, with the team driving back to Adelaide. In all, the project was a success with three vessels surveyed and will now be added to the shipwreck database. Other leads from the local community means, DEWNR will be visiting the southeast in the near future. Thank you to all the staff, volunteers and local community who have made the project go swimmingly. The whole week has been both educational and a joy—Carpenter “Rocks!”

by Kurt Bennett and Daniel Petraccaro

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