Thursday, October 28, 2010

AN EXCITING ANALYTICAL TECHNIQUE - X-RAY FLUORESCENSE SPECTROSCOPY:

Back in the early 1980s, I first heard of a very exciting analytical technique being applied to art history studies – neutron activation analysis. This was described in an article by Maurice J. Cotter, Neutron Activation Analysis of Paintings published in the January-February 1981 issue of American Scientist magazine (pages 17-27). It is based upon the same general phenomenon as C14 dating, that each element has its own discrete atomic half life. If you can use some form of radiation source to irradiate a sample and induce radiation in it, the rate with which that radiation dissipates (its half life) can be measured and analyzed to identify the discrete elements in the sample and their respective proportions. Of course, that reading would be of the remaining elements of the paint as well as the elements in the surface that the paint is on. By taking readings of an adjacent area of unpainted stone surface, a comparison would then illuminate the contents of the paint. Simply put, any difference in the readings between the two areas can be assumed to represent the contents of the paint. At the time I recognized that having portable equipment to do this would allow us to begin to identify the pigments used in the paint of pictographs, but alas, I am not a nuclear scientist.



Multiple colors, Notches Dome, WY,
Photo-Bonnie Newman, 2005

A technique similar to this has now been applied pigment analysis of rock art in just that manner in a fascinating project conducted by Bonita Newman and Dr. Lawrence Loendorf. They used portable x-ray equipment in July 2005 to analyze the elements in the pigments of pictographs at rock art sites. Newman described the process as follows:
Dr. Loendorf  taking a reading, Photo - Bonnie Newman, 2005

“Pigment analysis at the three selected sites was conducted with a portable x-ray fluorescence spectrometer. This small, light hand held unit provides non-destructive elemental analysis.

As the atoms of an element are struck by high energy photons from the x-ray source, electrons from the inner shells are knocked from their orbits around the nuclei of the atoms, causing those atoms to become unstable ions. To re-establish stability, electrons from the next higher shell move to the vacant inner orbits emitting energy as they move.

This phenomenon is referred to as fluorescence. Since each element maintains a different electron shell configuration, the spectrum produced by each episode of fluorescence is unique, allowing the element to be identified.”

Now think about how important this actually is. After a century of guessing and making assumptions about the chemical contents of the paint used in producing pictographs we can now know exactly what those elements are! Think of what a database this will eventually be.

In a future posting I will discuss some of the results of their studies.
ACKNOWLEDGEMENTS:
Bonita Newman is an archaeologist with ICI Corporation, Virginia Beach, VA., and is currently a member of the board of directors of the Colorado Rock Art Association. Lawrence Loendorf is a noted rock art researcher, a former president of the American Rock Art Research Association, and is a retired New Mexico State University professor.

Tuesday, October 19, 2010

IS ROCK ART REALLY ART?

One of the questions that beginners in rock art studies often get passionately involved in is “is rock art really art?” Indeed, it often seems that the less the person actually knows, the more passionately they adopt and argue their positions on certain questions, and this question of “is it art?” seems to generate more steam than most. We hear endless facile (and ultimately meaningless) statements about people (the creators of the rock art) who do not even have a word for the concept of art and who strive to do everything well (italics mine), etc.

The truth is, of course, that it has never been left up to the creators of material to designate its status as art. Indeed, it makes no difference what their intentions were when producing the images. Historically materials have received the designation of “Art” if they proved of interest to collectors, and once notice had been taken of these materials they were quickly incorporated into the field of studies designated as Art History.

Indeed, except for a short period of time during the renaissance it really wasn’t until a little over a century ago that the creators of works designated as art were consulted much at all about what they did. The producers of “Modern Art” argued loud and long for the artistic legitimacy of what they produced. The truth is as it always has been that the designation of what is or is not art has never depended upon the intentions of the creator. It has always come from the collectors who were fascinated by the material, and the scholars who subsequently studied and classified it.

So, is rock art really art? Of course it is. It is art because of the large numbers of people who find it so fascinating, and because I, as an art historian, have devoted the last 30 years of my life to it - and I say so.

Friday, October 15, 2010

ECHO PARK, DINOSAUR NATIONAL MONUMENT:


Petroglyph panel, Echo Park, Dinosaur National
Monument, CO. Photo: Peter Faris, 1986.

Among the many remarkable rock art sites in Dinosaur National Monument in Colorado and Utah is this panel at Echo Park. Created in the distinctive Fremont Indian style, these petroglyphs are high on a cliff face with the lowest elements a possible twelve to fifteen feet above the ground. The stream runs against the base of the cliff in this location so there is nothing but blank cliff and running water below these images. It does not look likely that people could have found good access to the cliff face here for making the petroglyphs so possibly this is an example of the valley bottom eroding down that far since the petroglyphs were created.

Single course Fremont bone plaque necklace, from
Exploring the Fremont, David B. Madsen, 1989,
Utah Museum of Natural History, p.41.

The main anthropomorph in the upper left quadrant of the photo is composed of nearly 300 dots with some form of elaborate winged headdress, eyes, a mouth, ear pendants, and a seven plaque bone necklace incised into the cliff surface. This style of necklace is quite common in the portrayal of individuals in the Classic Fremont Style rock art and numerous examples have been recovered. Below the necklace can be seen a belt or waistband as well.

What is the most remarkable about these petroglyphs, however, is the technique used to create them because they are created from lines of many dots that seem to have been drilled into the rock. As I said above, given the lie of these petroglyphs I could not get into a position to examine them closely, but given the apparent depth, and consistent size and roundness of these dots I assume that they are drilled holes. Even if these are created on sandstone rather than much harder stone like basalt, drilling this many holes represents an awesome amount of work.

Originally these figures might have been painted as well, as many Classic Fremont Style figures from this area included both pecking and paint, indeed traces of paint can still be found on many of them. Some of these are located at other sites in Dinosaur National Monument and many others at nearby McConkey Ranch north of Vernal, Utah.

In any case they represent a truly unique example in North American rock art.

Friday, October 8, 2010

THE GOLDEN RATIO IN ROCK ART:

Hunt panel, 9-Mile Canyon, Utah.
Photo: Peter Faris, 1985.

On April 17, 1987, I presented a paper at the Rock Art in the Western United States symposium at the Denver Museum of Natural History, co-sponsored by the museum and by the Colorado Archaeological Society. My presentation was titled Aspects of Design in Uintah and San Rafael Fremont Rock Art. In this I focused on analyzing rock art in terms of traditional design concepts in western art. Note that I was discussing rock art that predates any possible contact between cultures. In this I was postulating that preference for certain proportions and ratios are apparently hard-wired into the human brain. One of the design elements that I discussed on that occasion was the golden ratio (AKA: golden mean/golden section).
The golden ratio was of great interest to early mathematicians and has been used intentionally at least since the Renaissance by western artists as a basis for composition. Simply speaking, the golden ratio is a means of subdividing a line or an area in such a way that the ratio of the smaller portion to the larger is the same as ratio of the larger portion to the total. According to Wikipedia “two quantities are in the golden ratio if the ratio of the sum of the quantities to the larger quantity is equal to the ratio of the larger quantity to the smaller one. The golden ratio is an irrational mathematical constant, approximately 1.6180339887.”

In 1945, Max Raphael wrote in Prehistoric Cave Paintings that “The first surprise of the spectator who takes measurements is not that he finds proportions in all these lines and surfaces, but that these proportions – largely independent of the various animal species represented – can be reduced to a few recurrent types such as 1:1, 1:2, 2:3, 2:5, 3:5, 3:4, 3:7 and 4:7. The first two require no explanation because they can be achieved with any scale. The next three form the homogeneous group 2:3 = 3:5 which is known as the golden section” (p.28).

Raphael believed that early man had become aware of this ratio by noticing natural relationships of the digits of the human hand. His candidate for this relationship was the that the ratio of the width of the 4th and 5th fingers on one hand compared to the width of the thumb plus the 1st and 2nd fingers closely approximates the ratio of the width of the thumb plus the 1st and 2nd fingers to the width of all five fingers. Raphael also found the golden section in the body proportions of many of the animals portrayed in cave paintings.

Golden ratio proportions drawn on photo,
Hunt panel, 9-Mile Canyon, Utah.
Photo: Peter Faris, 1985.

The example that I presented for the golden ratio is the famous hunting panel from 9-Mile Canyon in northeastern Utah. In examining this petroglyph panel we first recognize that there are elements from more than one culture included and my analysis was focused on the original Fremont composition. It is obvious that the original composition composed a panel of the type that is sometimes called a “master of the animals” or “master of the hunt” composition. The classic Fremont figure on the upper center of the composition (often assume to be a hunt shaman) is surrounded by a grouping of quadrupeds which appear to be bighorns. These animals are all connected to each other and to the upper human figure by overlapping, and in some instances lines. Six or seven figures have been added later in a different style, predominately on the right side. Four of these are hunters carrying bows and were created at a later date with a more fluid and curving style by another hand and which would not have been part of the original composition. There are also shield figures which may be questioned but their presence does not change the proportions of what I take to be the original composition which consists of the upper central Fremont figure and the grouping of bighorns around him. When I focus on that, the ratio of the width to the height can be seen to be very closely comparable to the golden ratio. I believe that this was probably done subconsciously by the original Fremont artist. These proportions just “felt right” to the creator of the panel. Later figures were probably added to share the supposed spiritual power possessed by the panel. I believe that this ratio represents one of the elements in rock art that is not generally intentional, but comes from a common inherited, subconscious, human sensitivity to that ratio which is hard-wired into the human brain, possibly as a relic of our primate brain’s need to judge distances and proportions in the branches of the trees that housed our early ancestors.

This points toward at least one element that can be recognized in rock art that is attributable to our common humanity rather than cultural influences or stylistic choices, but I believe there are many other such elements.

REFERENCE:

Raphael, Max
1945   Prehistoric Cave Paintings, Pantheon Books, Washington D.C.