Pacific Obsidian Sourcing by Portable XRF

By Sheppard, Peter; Trichereau, Barbara et al. | Archaeology in Oceania, April 2010 | Go to article overview

Pacific Obsidian Sourcing by Portable XRF


Sheppard, Peter, Trichereau, Barbara, Milicich, Cristany, Archaeology in Oceania


Abstract

The use of portable XRF analysis to characterise the geochemistry of Pacific obsidians is reported. Obsidian source samples from New Britain, the Admiralties, Fergusson Island and the Banks Islands were successfully characterised and then used to source 966 samples of obsidian from three (SE=SZ-8, SE-RF-2, SE-RF-6) Reef/Santa Cruz Lapita sites. The analysis demonstrates the capabilities of portable XRF and confirms the previous analysis of this material by combined density and PIXE-PIGME techniques. Our conclusions also indicate the importance of the Bao source region at Talasea and support the earlier suggestion that during the Lapita period an important passage crossed the Willaumez Peninsula in the vicinity of the Talasea airstrip and the Bao sources.

Keywords: Obsidian, Lapita, geochemistry, XRF

**********

The earliest settlers of the Western Pacific carried along with them distinctive elaborately decorated pottery and obsidian from their immediate homeland region in the Bismarck Archipelago, where obsidian had been widely used since the Pleistocene (Fredericksen 1997; Summerhayes et al. 1998; Torrence et al. 2004; Torrence et al. 1992). The makers of this Lapita archaeological tradition moved quickly out into the Pacific at circa 3200 BP, transporting significant quantities of obsidian (Specht 2002) southeast over 2000 km across the first major water gap into Remote Oceania to the Reef/Santa Cruz Group (Green 1987; Sheppard 1993) and then on to Vanuatu (Galipaud and Swete-Kelly 2007). Small amounts of what was probably heirloom material was ultimately transported as far away as New Caledonia (Sand and Sheppard 2000) and Fiji (Best 1987), a straight line distance of over 4000 km.

Characterisation and sourcing of this obsidian has played a significant role in the examination of origins of Lapita cultural patterns, changing patterns of regional interaction in the Bismarck Archipelago, long-distance transport and interaction in the Lapita period, and chronology of resource use. Characterisation research has been popular since the late 1960s (Ambrose and Green 1972; Green 1998; Key 1968) and has made use of a wide variety of analytical methods, including emission spectroscopy (Key 1968), WD-XRF (Smith et al. 1977), INAA (Leach and Warren 1981), density (Green 1987; Torrence and Victor 1995), PIXE-PIGME (Bird et al. 1981; Bird et al. 1997; Summerhayes et al. 1998) and most recently ICP-MS (Ambrose et al. 2009) and Raman Spectroscopy (Carter et al. 2009). Since the development in the 1980s of the use of PIXE-PIGME for the non-destructive characterisation of obsidian by Roger Bird at the Lucas Heights Research Facility in Sydney (ANSTO), most geochemical characterisation of Pacific obsidians has been conducted using that technique.

Although the PIXE-PIGME at Lucas Heights has produced quality results, access is limited and costly if you wish to analyse many hundreds of samples and there are sample size limitations. As with all archaeological geochemical characterisation, there is a need for a cheap, fast, non-destructive and portable system which allows adequate source characterisation and discrimination. Developments in recent years in the area of portable energy dispersive XRF systems have made archaeologically-effective systems available at reasonable cost (Craig et al. 2007). In this paper we report our use of an Innov-X portable XRF system to characterise the Lapita obsidian sources and then source the obsidians recovered from the Reef/Santa Cruz Lapita sites (SE-RF-6, SE-RF-2, SE-SZ-8) excavated by Roger Green (1976; Sheppard 1993). Our work demonstrates the effectiveness of this system in rapidly and effectively characterising many hundreds of samples with a system based in our archaeological laboratories at the University of Auckland.

Obsidian sources

All reported source regions and sources used in the Lapita period are studied in this report (Appendix), with the exception of a source in Tonga which was used only by the Lapita settlers of Tonga. …

The rest of this article is only available to active members of Questia

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this article

This article has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this article

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited article

Pacific Obsidian Sourcing by Portable XRF
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    Buy instant access to save your work.

    Already a member? Log in now.

    Author Advanced search

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.