Audio News for October 13th to October 19th

Welcome to the Audio News from Archaeologica! I'm Laura Pettigrew and these are the headlines in archaeological and historical news from October 13th to October 19th.

Chaco Canyon corncobs add to prehistoric mystery

Our first story is from the southwestern United States, where new studies show that ancient Puebloans imported corn. The corn, or maize, went to feed the laborers who built the towering structures at Chaco (CHOCK-o) Canyon in the New Mexico desert. In fact, Chaco (CHOCK-o) Canyon's great ceremonial houses, including Pueblo Bonito and Aztec, could not have been built if not for imported maize, say the Colorado scientists whose research will be published this week in a national science journal. Mysterious Chaco (CHOCK-o) Canyon, built intermittently from the mid-800s to the mid-1100s, has confounded archaeologists for generations. Basic questions about the multistory structures remain, including why people would build in hostile terrain where few crops grew and why they would abandon the buildings so abruptly. Recently, high-tech scientific sleuthing tools have begun to answer those questions. Researchers matched the ratio of two weights of strontium, an alkali metal, to point to the specific soils where Chaco Canyon's corn was grown. Strontium is present at varying levels depending on the age of rock. Experts around the globe have used the isotope in tooth enamel to determine the origin of buried human remains and have analyzed the chemical's presence in ancient riverbeds to track the flow of long-gone rivers. Blown across the countryside like dust in the wind, it trickles through water, laces soil and becomes concentrated in plants. The dried Chaco (CHOCK-o) Canyon corncobs reflect the unique isotopic signature of the soil in which they were grown. And their signature is a perfect match for soil that lies 50 miles away. People carried the corn to Chaco on their backs in baskets, traveling well-marked foot trails. The finding that corn was imported underscores the complex nature of the Chaco Canyon culture. At least some of the imported maize went to feed huge gatherings for ritual ceremonies. But that was not the only import: Chaco also brought in turquoise for ornaments, varied styles of ceramics, and chert for stylized projectiles. During the equinox and solstice, the sun's rays and shadows were cast in specific places, calibrating the true position of east, west, north and south. The great house where the corn in this study was found lay on the axis of those cardinal directions.

Stonehenge scribbles traced by laser

At Stonehenge in the UK, laser scanning has revealed ancient carvings on the pillars that are invisible to the naked eye. The experiment scanned a portion of three of the 83 stones that make up the famous prehistoric monument. The newfound carvings are just a couple of millimeters deep and represent bronze axe heads. A few dozen visible carvings have been reported before, the earliest in 1953. But the comparison of the 50-year-old photographs with the new scans revealed that the carvings seem to be wearing away. Stonehenge was constructed in 2300 BC, but the carvings are thought to have been made after 1800 BC, which is when bronze axe heads began to be used. Carvings of axe heads, as well as daggers and cups, have been found at burial sites all over the UK, and appear to be a commemoration to the dead. It is believed the same could be true at Stonehenge, especially as there are hundreds of burial sites in the area around the monument. Other interpretations are trying to relate the carvings to the fact that the monument was designed to line up with the sunrise on the morning of the summer solstice, and thus served as a calendar. The current team spent just 30 minutes scanning the stones, but gathered nine million data points. These were converted into three-dimensional images using triangulation, based on the fixed positions of the laser and a camera.

Peruvian town uses Nazca Lines as dump

In Peru, a coastal town has set up a garbage dump inside the Nazca (NOS-ca) Lines. Sending trucks rumbling across the mysterious markings etched into the desert sands more than a millennium ago. 250 miles south of Lima, the lines stretch 35-miles over the of desert. They have mystified scientists and were added to the United Nation's Cultural Heritage list in 1994. Nazca (NOS-ca) Mayor Daniel Mantilla (man-TEE-ya) explained that the town decided to use the area as a dump in frustration after failing to get Peru's National Institute of Culture to approve a site. The town has momentarily stopped using the dump. The refuse is about knee high and spreads across an area 200 yards long and 60 yards wide. From the ground, the Nazca (NOS-ca) lines seem to be a confusion of rocks and soil, but from the air, figures can be seen, among them a hummingbird, a monkey, a whale, and a spider, some reaching 900 feet long. The garbage trucks have damaged two trapezoid-shaped figures. The Nazca (NOS-ca) lines, thousands in all, were made by the Nazca (NOS-ca) and Paracas (pah-ROCK-us) cultures by clearing aside darker rocks on the desert surface to expose lighter soil underneath. Scientists debate why the lines were built. Among the theories: they may have served as a calendar, or a map of underground water supplies.

English rock carvings puzzle archaeologists

Our final story is from England, where mysterious rock carvings engraved into strange shapes are baffling archaeologists. One resembles a heart, another a human footprint. "We have absolutely no idea what they are," says Mazel, an archaeologist at the University of Newcastle. He believes the carvings could be as ancient as 3000 years old. A farm worker alerted the researchers to the etchings on an isolated boulder, while they were investigating the well-known "cup and ring" rock art in Northumberland. These prehistoric etchings have been found across the UK. Carvings have been found before that have been dated back to the Neolithic Bronze Age and were probably done by early farmers. They were hacked into rock faces using stone pick axes. But the newfound carvings are very different as metal tools were likely to have been required to make them. They are sharper on one hand, but also quite smooth. So far, experts are puzzled as to their age and meaning.

That wraps up the news for this week!
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I'm Laura Pettigrew and I'll see you next week!