On Human Blood, Rock Art and Calcium Oxalate: Further Studies on Organic Carbon Content and Radiocarbon Age of Materials Relating to Australian Rock Art

By Gillespie, Richard | Antiquity, June 1997 | Go to article overview

On Human Blood, Rock Art and Calcium Oxalate: Further Studies on Organic Carbon Content and Radiocarbon Age of Materials Relating to Australian Rock Art


Gillespie, Richard, Antiquity


Loy et al. (1990: 111) reported an AMS radiocarbon determination of c. 20,000 b.p. (RIDDL-1270) from a rock-art site at Laurie Creek in northern Australia. The dated sample was said to contain specific human blood proteins extracted from a painted rock surface, and this result to be a valid age for the artwork. One author of that paper, on the evidence of his chemical and isotopic analyses of new samples collected in 1990, has withdrawn his support for the date (Nelson 1993: 893-4). Loy (1994: 148) has replied by restating confidence in his own immunological testing of rock samples from the site, and in the original interpretation of the date and the dated material.

This paper presents further analyses on rock-surface fragments from the same location, including samples taken from both painted rock art and natural unpainted rock surfaces. Three new AMS radiocarbon determinations on organic matter extracted from these rock surfaces are also reported, with my interpretation of the scientific aspects. I reject the original date from Laurie Creek and the interpretation of what was measured given by Loy et al. (1990) for analytical reasons and suggest some possible directions in the dating of rock-art.

Fieldwork

Samples for this project were collected at the Laurie Creek site in 1990 by a group including the author, T.H. Loy, D.E. Nelson, R. Jones, C. Chippindale and B. Meehan. Jones and Meehan had collected the original dated sample on a first visit to the site in 1987. My responsibilities, as a specialist radiocarbon chemist, were to perform chemical analyses for carbon and amino acids on rock-surface and other samples collected, as a guide to selecting samples that might contain sufficient organic carbon for useful AMS dating of the artwork.

Preliminary chemical testing in the field suggested traces of calcium carbonate in many of the natural rock skins; the white pigment in painted artwork of the site was shown most likely to be magnesium carbonate, rather than clay or calcium carbonate, by its delayed-effervescence response to dilute acid. Many natural and painted skins in the area contain surface algal or lichen growths; insect and bird droppings are common; mud-wasp nests or their remains occur in some of the rock shelters; charcoal particles, from bushfires that regularly pass through the area during the dry season, are present everywhere. All these materials contain significant amounts of organic carbon, which would be of more recent origin than the artwork they overlie.

A simple soil chemistry wet oxidation method(1) was used to analyse for total organic carbon. Sample sizes were 0.5-1.0 sq. cm of rock skin about 2-3 mm thick; we took fragments of flaking or exfoliating skins from the artwork which were close to falling off the walls, similar pieces were sampled from natural unpainted surfaces as controls. Results from the field analyses for carbon are shown in TABLE 1, with the immediate general observation that there is sufficient carbon for an AMS determination in most of the painted and natural unpainted samples tested, in the range 200900 micrograms per sq. cm. The relatively abundant organic carbon found - a surprise - encouraged the second series of field analyses for amino acids(2). Results from field testing for soluble and insoluble amino acids are also presented in TABLE 1, and show very low abundance of amino acids for most samples. Two painted artwork skins had levels approximating 50 micrograms amino acids in the insoluble fraction, and two soluble fractions, one on yellow painted artwork and one from adjacent to the location of the original dated sample, also indicated about 50 micrograms amino acids. All other samples tested contained at best trace amounts.

Laboratory work

Total organic carbon measurements using similar methods on painted and unpainted skins confirmed the field analysis results. X-ray diffraction scans of four natural skins from engraved rock surfaces showed the presence of the calcium oxalate mineral whewellite at levels of 0. …

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

On Human Blood, Rock Art and Calcium Oxalate: Further Studies on Organic Carbon Content and Radiocarbon Age of Materials Relating to Australian Rock Art
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.