The Magnetometer Does Not Lie

In my conversations with Dr. Chet Walker over the last couple of years, he’s said this on several occasions: “The magnetometer does not lie.” The magnetometer accurately reflects what is buried in the ground. However, this does not mean that every magnetic anomaly viewable in the Moundville survey map represents a prehistoric feature. To the contrary, many represent modern metal trash: nails, tent pegs, rusty pin flags, old bullets, bits of wire. We certainly have hit a bit of that during past seasons of the MPP. But after the first full week of this summer field season, we’ve yet to hit anything of the sort. All but one of our excavation units have already uncovered ancient architectural remains.

The indigenous peoples of the eastern United States rarely built in stone. Their construction materials came from the hard- and softwood forests, cane-choked riverbanks, and red and yellow clay seams that could have been found within an arrow shot of most settlements. Nowadays, little more than stains in the soil are all that can be found of most prehistoric houses, temples, and civic buildings, but stains in the soil are enough for the purposes of Southeastern archaeologists. And we get excited about such things!

Artist’s rendition of a Mississippian house. The remains of several types of houses have been found at Moundville. This is the wattle-and-daub type that was often raised in wall trenches.

Team 1’s quick but careful excavation in the northwestern plaza has revealed a series of wall trenches which we believe are sections of the north wall of a large, square building that postdates plaza construction. Wall trenches are the hand-dug slots into which the Moundville people lowered pre-fabricated sections of wooden wall. This construction technique was once quite widespread in the southeastern United States, practiced by populations from as far north as Illinois, south as Florida, and west as Oklahoma. It was dominant at Moundville throughout the 14th, 15th, and 16th centuries. One of the Team 1 wall trenches has already been excavated. Judging by its depth – approximately 80 centimeters (almost 3 feet) – the associated building must have been quite substantial. The locations of old posts removals can still be seen at the base and sides of this excavated wall trench.

Team 1’s first unit. Note the two yellowish brown strips cross-cutting the unit. These are the wall trenches that the magnetometer picked up on.

An excavated wall trench. The trench probably originally began at the plaza surface, but its shallowest portions were destroyed by plows during the 19th and 20th centuries. We noticed the stain as soon as the “plowzone” had been removed.

Erik Porth and Daniel Cardwell are mapping the contours of the excavated wall trench. We have forms for just about any situation and are careful to document everything we encounter.
Erik and Daniel are already such good friends that they have decided to coordinate their clothing for the remainder of the summer. They bring an unprecedented level of panache to the MPP.

On Thursday, we doubled the size of Team 2’s 1-x-2 meter unit in order to get a better idea of what exactly they’d encountered. Before expanding, we noticed a yellowish sandy area taking up the southwest quadrant of their unit. It stood out because the rest of the unit consisted of the reddish-brown clay-rich soil that is typical of plaza area. We now know that this sandy zone extends straight to the south, still with the reddish-brown clay surrounding it. We are beginning to think that Team 2 has uncovered the top of a square-sided pit, probably the semi-subterranean floor of a square pit house. The magnetometer map shows what appear to be clusters of small houses in this area (see Team 2 mag image in “The First Two Days” post, below). I’ll post photos of Team 2’s excavation unit after we get a good shot on Monday.

Aaron Posey is measuring the depth of the unit to make sure we keep things uniform and accurate.

Team 3 has already completed its first unit. That’s because we hit sterile subsoil right under the plowzone! Most people probably think that you can put a shovel in anywhere at Moundville and turn up interesting things, but that’s simply not the case. Team 3’s first unit was a bust – no artifacts, no archaeological features. We had expected to find a large post (see Team 3 mag image in “The First Two Days”), so this left me a bit baffled as to what could have caused the magnetic anomaly. But don’t lose heart! Soon thereafter, we began our second unit less than 6 meters from the first and, lo and behold, revealed what looks like a good-sized post stain right where one should be. Team 3’s top priority on Monday is to figure out if this stain is, in fact, what we think it is. I’ll keep you “posted,” as usual!

Traci Roller and Kimberly Peace had a good time mapping profiles on Friday.

See the dark circular post stain in the lower right quadrant? This post was probably erected after the plaza was constructed.

A dragonfly dropped by to impress us with his size, but we didn’t think he measured up.


Moundville Culture and History – An Overview

The Moundville site of west-central Alabama was the seat of a Mississippian chiefdom that originated in the thirteenth century and rapidly rose to regional prominence. At its political height it was a place with all of the monumental hallmarks of a Mississippian capital town, a built ceremonial landscape composed of 29 earthen mounds arranged in pairs around an expansive plaza, all of it enclosed within a mile-long wooden palisade studded with archers towers. The rectangular mound layout forms a “sociogram,” a massive social and cosmological symbol in which the size and position of each mound pair correlates with the size and status of the segmentary kin-group that used it. Mound summits were crammed with special structures: craft workshops, ritual buildings, and the residences of influential families. Some of these were large, over-engineered constructions employing meter-wide cypress logs as internal roof supports. Moundville was built to impress.

The “Duck Bowl,” painstakingly carved from a diorite boulder.

A ceramic bat effigy vessel. This charming object is also a rattle – the bat’s head is hollow with pellets loose inside.

The “Willoughby Disk” is a stone palette upon which Moundville priests mixed medicinal resins and pigments. The iconography relates to tobacco smoking, ancestors, and the supernatural origins of the object.

Moundville artisans were some of the most talented in the Mississippian world. They crafted in stone, shell, copper, and clay in addition to media that have not survived the intervening centuries of Southern humidity: wood, cane, and natural fiber. They created images of the creatures that populated their world. These included frogs, fish, bats, ducks, woodpeckers, owls, raptorial birds, panthers, and others animals with which we are all familiar, in addition to a pantheon of composite monsters and supernatural men and women.

The chiefdom incorporated a population of at least 10,000 men, women, and children who were distributed among small farming settlements along a forty-kilometer stretch of the Black Warrior River and its tributaries. Each household made what it needed to survive (tools, food, cooking pots), but were connected to more distant populations through trade networks that funneled through the capital town. Titles and property, including agricultural fields but excluding weapons, were probably handed down through women. Men pursued social advancement through war. Healthy individuals who survived childhood could expect to live between 40 and 50 years.

The rise and fall of Moundville parallels that of other large Mississippian polities: rapid coalescence within the span of two or three generations, a subsequent period of relative stability, and a final protracted decline. By the 15th century, the chiefdom was a shadow of its former self. The bulk of Moundville’s populace had lost faith in its leaders, the great compromise chartered with the mound and plaza arrangement over 150 years before dissolved amidst political factionalism. The less influential families who had resided in the southern part of the capital town, abandoned the mounds of their ancestors and dispersed into the hinterlands. Their followers came with them. They established new communities centered on new mounds, but periodically returned to the depopulated capital to conduct solemn burial rites at the exact locations of their former dwellings.

Plan or “bird’s eye” map of typical early period Moundville houses (rectangles) with intruding late period burials (dark ovals). From Between Plaza and Palisade: Household and Community Organization at Early Moundville by Gregory D. Wilson, page 97.

Hernando de Soto passed through the area in the early 1540s. His chroniclers make no mention of what was surely the largest mound center along the route. Moundville had been falling into ruin for decades by then. The Black Warrior Valley, once the center of one of the largest and most socially and politically complex societies in prehistoric North America, was an uninhabited borderland between warring proto-Creeks and Choctaws by the end of sixteenth century.