This illustration shows the main features of Poverty Point in northern Louisiana. The Mississippi River flood plain is shown in the green. Macon Ridge is the highest point on which the site is situated. The site is home to six C-shaped ridges. Some of the ridges were damaged by modern and historical activities. Farm activity is responsible for the pattern south of MoundE. The site's lower areas are lighter in color and may be due to soil being mined for ridges or mounds. The Mississippi River flood plain is shown in the green. Macon Ridge is the highest point on which the site is situated. The site is home to six C-shaped ridges. Some of the ridges were damaged by modern and historical activities. Farm activity is responsible for the pattern south of MoundE. The site's yellowish-colored areas are likely to have been mined for soil to create ridges or mounds. Credit: T.R. Kidder
It is believed that the Native Americans who lived in Poverty Point, northern Louisiana over 3,000 years ago were simple gatherers and hunters. New archaeological discoveries from Washington University in St. Louis paint a completely different picture of America’s first civilization.
These early Indigenous people did not live in the simple life often depicted in anthropology books. They were skilled engineers who could build massive earthen structures in a matter months, possibly even weeks. This skill has stood the test of time, as the findings prove.
Tristram R. stated that "we as a research community and the population as a whole have undervalued native people's ability to do this kind of work and to do so quickly in such a way they did." "T.R." Kidder, the lead author and Tedi Macias Professor in Anthropology in Arts & Sciences.
"The most amazing thing about these earthworks is their ability to hold together for over 3,000 years without major erosion or failure. Modern bridges, highways, and dams are inexplicably more susceptible to failure than they are because it is much harder than you might think to build things from dirt. They were truly amazing engineers with sophisticated technical knowledge."
These findings were published in Southeastern Archaeology, September 1, 2021. The paper was also co-authored by Kai Su, Seth B. Grooms from Washington University, and graduates Edward R. Henry (Colorado State), and Kelly Ervin, (USDA Natural Resources Conservation Service).
Poverty Point World Heritage Site is a 72-foot-tall, earthen mound with concentric half-circle ridges. These structures were built by hunter-gatherers around 3,400 years ago using nearly 2 million cubic yards soil. Amazingly, these structures were built without modern tools, domesticated animals, or even wheeled cars.
Before sampling. The color differences between layers are obvious. The darker layers contain carbon-rich deposits that have been made by humans. These include midden, garbage or other materials that were dumped during construction to create the ridge structure. The upper third has very little organic garbage. Credit: T.R. Kidder
Kidder claims that the site was a significant religious site for Native Americans, where they could make pilgrimages, much like Mecca. It was likely to have been abandoned between 2,000 and 2,200 years ago, most likely because of documented flooding in Mississippi Valley or climate change.
There are a lot of artifacts on the Poverty Point ridges, both within and around them. This suggests that there were once people living there. Kidder and his team reexcavated and reevaluated Ridge West 3 at Poverty Point Site, which was first excavated in 1991 by Jon Gibson, a renowned archaeologist.
Modern research methods, including radiocarbon dating and microscopic analysis, as well as magnetic measurements of soils, provide conclusive evidence of earthworks' rapid construction. There is no evidence of any weathering or boundaries between the levels. This would be possible if there had been a short pause in construction. Kidder believes that the construction was completed using lifts or sediment layers to increase the ridge height, linear dimensions and expand the footprint horizontally and vertically.
What is the significance of this? Kidder says that the findings are contrary to previous assumptions about pre-modern hunters/gatherers behavior. To build the massive mounds and ridges of Poverty Point, it would have been necessary to have a large labor pool organized well and for this to be possible. Leadership would have been required. It was believed that hunters and gathers avoided politics.
"These data show that we have native people working together on the site, thanks to the speed at which excavations and construction took place. Kidder stated that this is a remarkable feat, as hunter-gatherers shouldn't be allowed to perform these activities.
Even more remarkable than the speed at which the structures were built is their continued integrity. This area is close to the Gulf of Mexico and receives a lot of rain, which makes it especially vulnerable to erosion. Microscopically analyzing soils reveals that Native Americans used a combination of silts, soilclays and sandin to strengthen their structures.
"In a similar fashion to Roman concrete and rammed earth in China," Kidder said. Native Americans found sophisticated ways to mix different materials to make them almost indestructible despite the fact that they were not compacted. Kidder stated that there is some magic in the mix that modern engineers are still not able to understand.
More information: Tristram Kidder et. al. Multi-method geoarchaeological analysis demonstrates extraordinarily rapid construction of Ridge West 3 in Poverty Point. Southeastern Archaeology (2021). Tristram R. Kidder and colleagues, Multi-method Geoarchaeological Analyses demonstrates an exceptionally fast construction of Ridge West 3 in Poverty Point (2021). DOI: 10.1080/0734578X.2021.1958445
