Rock Talk By Larry Larason

Correlating History

Snakes and Climate

As any reader of mysteries knows, the detective must reconcile time lines in order to figure out who did the dastardly deed. Archaeology now has so many ways of dating objects and events that reliable chronologies can be established even for prehistory. In geology the term "correlation" relates to establishing time equivalence in widely separated rocks. I recently had occasion to try to correlate, in the geological sense, some prehistorical artifacts.

I was flipping pages in a book about the mound building cultures of the ancient Midwest and Southeast U.S., mostly looking at pictures, when something caught my interest. What made me pause were winged serpents – rattlesnakes – inscribed on a conch shell. I hadn't realized that the Mound Builders had such metaphorical creatures in their mythology. Here in the Southwest horned or feathered serpents play roles in Pueblo cosmology. The Zuni have Kolowisi, the Rio Grande Pueblos Avanyu, and the Hopi Paaloloqangw. And, everyone has heard of the Aztecs' Quetzalcoatl. Somewhat less well known is the Mayan Kulkulcan. Some of these serpents have feather crests while others have horns. The depictions I'm most familiar with are in rock art; it is not always clear whether the serpent has a feather crest or a horn. We can refer to them collectively as "crested." Do these mythological beasts imply a connection between the Southwestern and Mexican cultures and the Mound Builders?

After I became intrigued by that question, I looked at the timeline for the Mound Builders. I noticed that Cahokia, the largest and arguably most important of the mound sites, began building about the same time as Chaco. That really got me interested in the correlations between the two regions. I began digging through books and websites to see what I could learn.

So who were these builders of mounds? Probably, like the ancient Puebloan societies, they were not a single people speaking a common language, but they shared the practice of piling dirt up for various purposes. The mounds, at different times and places, served as cemeteries, for ceremonial functions, or raised platforms for housing. Some mounds were built in simple conical shapes, while others were effigies of birds, snakes, and other creatures.

I lived for several years in northeastern Louisiana, where there are 700 known mound sites, although many have been destroyed by farming. Notable among them is Poverty Point, now protected as a state park. The site contains six concentric, semi-circular mounds along the bank of Bayou Macon that were built about 1500 BCE. The Poverty Point people placed their houses on top the mounds. They also built several monumental earthen pyramids for ceremonial use, both in the central plaza and behind the residential area. The largest pyramid was 50 feet high and aligned to the path of the sun. Poverty Point was considered the oldest mound site until 1998 when Watson Brake, also in northeastern Louisiana, was dated to 5400 years before the present, nearly 2000 years older than Poverty Point. Amazingly, both these sites were built before the invention of agriculture or pottery. Watson Brake seems to have been inhabited only seasonally.

The later story of the Mound Builders is complicated. In Ohio the Adena and Hopewell cultures flourished between 400 BCE and 400 CE. By 900 CE mounds were being built all along the Mississippi River and its tributaries, with Cahokia, located near present-day St. Louis, Missouri, as the probable religious and political center. It was the largest of many mound sites, so I will focus on it.

Archaeologists call these sites built after 900 CE the "Mississippian Culture". Cahokia, with an estimated population of 15,000, has been called the only prehistoric "city" north of Mexico. But the people living there were not urbanites; they were mostly farmers. Still, among them were highly skilled artisans working in a variety of materials gathered by a far-flung trade network: shells from the Gulf coast, copper from upper Michigan, mica from North Carolina, and obsidian from Wyoming. Of course, they also worked flint and other stones and made outstanding pottery, including effigy pots that remind me of Mexican ones. Spiro Mounds in Oklahoma was another center of the Mississippian Culture; it began building at the same time as Cahokia. When Spiro was looted in the 1930s, it became known as "the American King Tut's Tomb." In at least the later years of Spiro we know there was trade with the Pueblos, certainly as far west as Pecos.

This is a too brief summary of the Mound Builders, but it's time to get back to the serpents. Before going further, let's decide when is a snake a serpent? Think about the two words. "Snake" starts with a hiss and then ends abruptly; it sounds like a cry of alarm. Serpent is more poetic, more mythical. I've never seen anyone write about the snake in Eden; it's always a serpent that tempted Eve. So, since we're talking about mythological images, I'll use the term "serpent."

As Poverty Point was being built, some unknown people in the Southwest were painting eerie figures on sheltered rock faces. Polly Schaafsma originally defined the style in 1971. It's called the Barrier Canyon Anthropomorphic style (BCA) with a time line from 1500 BCE until 500 CE. It cannot be related to any of the cultures in the region because it appears mostly in places that even at that time must have been isolated "outback" and no artifacts are associated with it. Crested serpents are fairly common in BCA art. At the same time the earliest known representations of the feathered serpent that would become known as Quetzalcoatl began appearing at Olmec sites in southern Mexico.

What do the serpents mean? Polly Schaafsma wrote "…their kaleidoscopic attributes change or shift as they appear in different contexts and through time." In other words, it's complicated. She does point out that they represent a union of earth and sky. If I tried to explain much more I would be in over my head. Let's just say that generally they are associated with water in both its beneficial and destructive aspects.

Oddly, the serpents disappear from the Southwest along with the BCA artists; there are no known crested serpents in Basketmaker or early Puebloan rock art. They reappear in the Southwest, first in the Mimbres area around 1000, almost certainly an example of influence from Mexico. From what I can find, there are no supernatural serpents in the iconography of the Chacoan sphere contemporary with Cahokia. So, mythic serpents offer no hint of relationships between the two areas.

What about the time lines? Archaeologist Brian Fagin has written several books about the rise and fall of civilizations correlated with climate. He doesn't address the Mound Builders, but the building of both Chaco and Cahokia began as the Medieval Warm Period took hold. This was an optimal period for agriculture and around the time when Icelanders colonized Greenland, for example, and the Incan civilization rose to new heights. Average temperatures and global models don't tell the whole story, though. Just look at the past year [2007]. Arizona was hotter and drier while New Mexico was cooler and wetter, parts of the state experiencing flash floods. The American Southeast is suffering the worst drought in its history. And England flooded while Greece burned. Correspondingly, as Cahokia and Chaco were flourishing, the older Mayan kingdoms in Central America were being destroyed by drought. Wherever you live, the climate that matters is local.

We know the fate of Chaco, brought down by the "Great Drought" of 1275-1299. What became of Cahokia? Many square miles of forest had been cleared around Cahokia for corn fields; firewood and game animals were scarce. After the Cahokians diverted a creek, their cornfields were frequently flooded, destroying crops, beginning at about 1100 CE. They were also hit by an earthquake about 1200 CE, a precursor of the one that occurred in 1811 along the Mississippi River. The city never completely recovered. There seems to have been social unrest, possibly a revolt against the elite, and by 1350 the site was nearly empty. Erratic weather commencing with the onset of the Little Ice Age about 1300 gradually destroyed the other centers of Mississippian culture, as well.

So what did my correlations prove? Not much. I found no way of explaining the ubiquity of mythic serpents. To explain the Greek myths Robert Graves wrote about ancient people encountering depictions of mythic events misinterpreting them, sometimes deliberately, and in the process creating new myths. He coined the term "iconotropy" for this process. Perhaps items with representations of crested or winged serpents, traded among tribes, led to new myths to explain the images, and later new images to illustrate the new myths.

Finally, I learned that winged serpents were not restricted to the Americas. One notable example is Wadjet, an Egyptian deity, who was believed to control the waters of the Nile. Perhaps mythic serpents, as symbols of a unity of earth and sky, simply arose from the deep well of mythic imagination.