Professor Frank Murray
School of Environmental Science
Perth, WA 6150
Dear Professor Murray,
Re: Preservation of Murujuga (Burrup) rock art
State Development Minister Clive Brown has announced tenders for
six studies under the aegis of the Burrup Rock Art Monitoring
Management Committee which you chair:
1. Baseline assessment of microbial activity on rock surfaces;
2. Microclimate and deposition at rock art sites;
3. Monitoring of ambient concentrations of industrial emissions;
4. Artificial fumigation of rock surfaces;
5. Field studies of colour changes to rock art; and
6. Field studies of micro-topography changes to rock art.
In response I offer the following comments:
1. Microbial activity is hardly relevant, the main problem, as has
been adequately established by previous study, is industrial
acidification. It is possible, but improbable, that this has also
exacerbated microbial action, but this is at most a peripheral issue.
2. Microclimate and deposition: deposition of fine particle
fallout has certainly been a problem since the establishment of the
Hamersley Iron plant, which has spewed out 518,000 tonnes of
particulate matter of under 10 microns so far. Further quantification
is of marginal interest, it is certainly not the most pressing issue
here. Microclimatic study appears to be a soft option, and is hardly
relevant to the main issue, that of acidification. Microclimate has
been subjected to extensive studies in rock art conservation, with very
little if any useful data having been acquired that way.
3. Ambient concentrations of industrial emissions: this is most
useful because appropriate data remain unavailable. It is of course
necessary to check levels against a control site, a safe distance away,
and I trust that such data will be required.
4. Fumigation of rock surfaces: we already had fumigation with
hundreds of thousands of tonnes of NOx and SOx, not to mention hundreds
of millions of tonnes of CO2 and 80,000 tonnes of volatile
hydrocarbons. What is the purpose of this proposal? Are you assuming
that the rock art is being damaged by biota? How do you propose to
fumigate the peninsula, and with what?
5. Colour changes to rock art: a highly valid requirement, bearing
in mind that this is what determines the survival of the petroglyphs.
However, a four-year study is hardly very effective. Having monitored
the Murujuga colour changes since 1967 I do not believe that this
short-term effort is a substitute for long-term work. I shall closely
scrutinise the results of this study.
6. Micro-topographical changes to rock art: presumably by laser
equipment, as you indicated in April. Firstly, this is pointless
because the changes at the atmosphere-lithosphere interface are not of
bulk, but are primarily compositional. Moreover, laser equipment has
been used before in the study of petroglyphs, of a sophistication not
even available in Australia (see work by Steguweit in Germany), and I
have published some of it. This, however, is unsuitable in our case,
the use of this technology is for the topographical study of groove
shape, striae and technological traces, not for modifications of
This list implies that there is an appreciation lacking of the
nature of the problem, and of the nature of the mineral accretion on
whose preservation the existence of the petroglyphs depends largely.
The accretionary deposit consists of both endogenic and exogenic
materials, dominated by several iron compounds that are subjected to
progressive and probably ongoing modification towards the most stable
phase of Fe2O3, haematite. Numerous other cations are also present,
particularly manganese, and these crusts comprise significant clays and
aeolian detritus, including quartz, tourmaline and other crystal
grains, plant matter and even charcoal fragments. They are subjected to
continuous modification by rainwater under natural conditions, which
favours the formation of distinctively ‘laced’ or ‘terraced’
micro-morphologies. I consider it the task of the project you are
charged with to study this material thoroughly, and to arrive at an
informed opinion as to what the effects of industrial air shed
pollution on this deposit are. Nothing in the above list suggests to me
that you have provided a program to deal with these matters, or that
the task of this project has even been fully understood.
The most obvious omissions from your list of proposed studies are
that there is no provision for the most important component, a thorough
study of the patina by field microscopy. There is no attempt to involve
geochemists specialising in this subject, nor is there an intention to
conduct accelerated weathering experimentation. Even the most basic,
and most urgently required study is omitted, a study of precipitation
characteristics, with special attention to pH and chemistry of
rainwater, and its effects on the substrate.
Having consulted the council of the Federation, I have to advise
you that we regard much of your proposed list of works as a waste of
taxpayer’s money. Most certainly, the issue of the deteriorating rock
art of Murujuga will not be solved, or even illuminated by these
Thank you for considering our view.
Robert G. Bednarik
President and Permanent Convener, IFRAO
Professor Murray, who is conducting a four-year study of the
Dampier rock art deterioration, has on 13 January 2004 in a meeting
with World Monuments Fund President Bonnie Burnham pre-empted his study
by stating that the Dampier emissions cannot be any danger to the rock
art, they amount to only 5% of the permissible maximum level. His
comments are at odds with the findings of the government's own EPA study of January 2004, according to which the maximum limits are in several ways exceeded.