CAVE ART -- IMPROVEMENT IN DATING REVEALS NEW FACTS ABOUT THE ARTISTS OF PREHISTORY

Because I teach prehistory to 6th graders in an enrichment program in the Tri-State (NY,CT and NJ) area of the U.S. I was especially interested in the following story that appeared in the NY Times by John Noble Wilford this week.

Stone Age artists were painting red disks, handprints, clublike symbols and geometric patterns on European cave walls long before previously thought, in some cases more than 40,000 years ago, scientists recently reported after completing more reliable dating tests that raised a possibility that Neanderthals were the artists.
A more likely situation, the researchers said, is that the art — 50 samples from 11 caves in northwestern Spain — was created by anatomically modern humans fairly soon after their arrival in Europe.

The findings seem to put an exclamation point to a run of recent discoveries: direct evidence from fossils that Homo sapiens populations were living in England 41,500 to 44,200 years ago and in Italy 43,000 to 45,000 years ago, and that they were making flutes in German caves about 42,000 years ago. Then there is the new genetic evidence of modern human-Neanderthal interbreeding, suggesting a closer relationship than had been generally thought.

The successful application of a newly refined uranium-thorium dating technique is also expected to send other scientists to other caves to see if they can reclaim prehistoric bragging rights. In the new research, an international team led by Alistair W. G. Pike of the University of Bristol in England determined that the red disk in the cave known as El Castillo was part of the earliest known wall decorations, at a minimum of 40,800 years old. That makes it the earliest cave art found so far in Europe, perhaps 4,000 years older than the paintings at Grotte Chauvet in France.

The handprints common at several of the Spanish caves were stencils, probably made by blowing pigment on a hand placed against the cave wall. The oldest example, at El Castillo, proved to be at least 37,300 years old, which the scientists said “considerably increases the antiquity of this motif and implies that depictions of the human hand were among the oldest art known in Europe.”

At Altamira, the researchers obtained a date of at least 35,600 years for a red club-shaped symbol. Archaeologists said this indicated that Altamira’s artistic tradition started about 10,000 years earlier than once estimated, and the cave appeared to have been revisited and painted many times over a span of 20,000 years.

In a report published online in the journal Science, Dr. Pike and his colleagues noted that the oldest dated art is “nonfigurative and monochrome (red), supporting the notion that the earliest expression of art in Western Europe was less concerned with animal depiction and characterized by red dots, disks, line and hand stencils.” The more stunning murals of bison and horses came gradually, later. Although the early dates coincide with recent evidence of a Homo sapiens presence in Europe, the scientists wrote that because 40,800 is only a minimum age, “it cannot be ruled out that the earliest paintings were symbolic expressions of the Neanderthals,” who were living in that part of Spain until at least 42,000 years ago. These close relatives of modern humans had lived in Europe and parts of Asia since at least 250,000 years ago, becoming extinct about 30,000 years ago.

In a teleconference for reporters on Wednesday, Dr. Pike said the older dates suggested three possible interpretations. One: Homo sapiens entered Europe with the tradition of cave art already part of the culture. Another possibility is that this artistic culture arose shortly after modern humans reached Europe. “It might have been the result of competition for resources with Neanderthals,” Dr. Pike said. “The rate of cultural innovation was accelerating, and this was a byproduct.” The third possibility, which the scientists said they had not anticipated at the start of their project, is that some of these earliest works of cave art might be attributed to Neanderthals. Until recently, archaeologists usually saw Neanderthals as incapable of creating artistic works much beyond simple abstract markings and personal ornamentation.

Other scientists were expected to be skeptical, pending more evidence of even earlier dates for cave art or of painting associated with Neanderthal tools or fossils. Eric Delson, a paleoanthropologist at Lehman College of the City University of New York, said, “There is no need to hypothesize that Neanderthals created these paintings, as we have evidence of artistic Homo sapiens already in Western Europe.”

The research is “most important,” Dr. Delson said, because it introduces a significant advance in techniques for more reliable, precise and older dating of antiquities, especially cave art that in most cases does not lend itself to reliable dating by radiocarbon methods. Dr. Hellstrom, in his article, recommended a wider application of the improved uranium-thorium dating method.

It is actually a 50-year-old technique, but a vastly improved one. Cave art is typically found in limestone terrain. Water seeping into caves leaves deposits of calcium carbonate, or calcite, as stalactites and stalagmites or simpler crusts cover cave surfaces. To date a painting under such a crust, researchers remove a piece of the calcite, dissolve the sample and extract the traces of uranium and thorium atoms. Over time, the uranium in the crust decays into thorium. A measure of the ratio of uranium to thorium gives the minimum age of the art beneath the crust.

This is an improvement over radiocarbon dating, which becomes less reliable at ages over 30,000 years and is not usable in dating art unless the pigment contained carbon. The uranium-thorium method has been made more sensitive, so that calcite samples about as small as a grain of rice can do the job.

Asked how the Neanderthal question could be resolved, Dr. Pike said, “Simply go back and date more of these samples and find something that predates modern humans in Europe