Monday, August 31, 2015

LIDAR and Infrared Imagery Reveals Many More Terrace Complexes in Appalachia

This is excellent work. by going out and doing what was done originally we discover just how the environment actually responds.  Better yet this is an excellent way to exploit a hill sided with natural reentries already in place to carry off runoff.   That allows a simple irrigation ditch set at the top of every terrace to allow seepage into the bed beneath.  All that captures ample water from every shower or thunderstorm that passes through and forces the water into a retaining grid of channels.

I cannot imagine a better use of a hillside ever.  Today we want wider terraces to allow equipment access but that should be mostly practical.  The idea of simply using four inch stems to make up retaining walls is also dead simple and a great reason to properly groom your woodlot.  Rebar will hold the stems in place as is done here.

You could even produce that irrigation ditch with a single blade plow.

I do not see direct evidence yet of these original farmers applying bio-char although the time frames appear very short.  I do not think that it was necessary in this country using the methods i see here.
LIDAR and infrared imagery reveals many more terrace complexes
Imagery provides convincing evidence that most terrace complexes contained log retaining walls and perhaps all began as log-walled earthworks. The majority of terrace complexes are at opposite ends of the Blue Ridge Mountain Range in Georgia and Virginia. Go figure?

Article Two of the Magic Biochar Garden Series

The Track Rock Terrace Complex, near Blairsville, GA is massive. Continued research by the volunteers of the People of One Fire have revealed pre-European man-made structures far beyond the original site plan of the Track Rock archaeological zone, created by a archaeological consultants for the US Forrest Service in 2001.

One may visit these amazing stone ruins a dozen times and still find man-made features that were missed before. It is also quite easy to become disoriented any time of year because of the dense foliage and undulating terrain.

Next time, however, when you hike at Track Rock, take a look down the mountainside about 100 yards past the point were the access trail passes across a branch and ravine that mark the northern boundaries of the terraces. You will see row after row of terraces that have no stone retaining walls. This section of the complex was completely overlooked as were the stone-walled terraces farther down the mountainside that even extend across Track Rock Creek.

These terraces without stone walls were many of the puzzles that we initially faced in 2012. Were they created by Native Americans or by farmers, who owned the land prior to it being purchased by the US Forest Service in the mid-20th century?

The answer came after several county governments in North Georgia provided POOF with LIDAR and infrared imagery of suspected terrace complexes in their locales. County leaders had been frustrated for years by the response of Georgia archaeologists, when asked to help in understanding their enigmatic ruins. In most cases, the archaeologists refused to look at their sites. When they did, bitter schisms developed within the profession. One faction interpreted the stacked stones to be the work of early frontier farmers. The other and smaller faction insisted that the stone walls and cairns were the work of Native Americans.

Because of the schisms, the county leaders were unable to get the precise archaeological descriptions that were necessary to save these amazing sites from real estate developers.  The parking lot of the Mall of Georgia, one of the nation’s largest, was built over stone walled terraces, because three archaeological firms refused to certify the terrace complex as being either prehistoric or  historic! No radiocarbon testing was done.  The refusals were based on biases, mainly that Georgia’s Creek Indians lacked the intelligence to stack one stone over another.

POOF researchers began noticing a feature at the terrace complexes in Northeast and North-central Metro Atlanta that also occurs at Track Rock Gap. All sites had stone cairns on the southwest slopes of hills or mountains. All had at least some stone walled terraces near the tops of hills. However, on the lower slopes, just like at Track Rock there were still the vestiges of terraces that had no stone walls. Some stones were laying on the earthen slopes of terraces, but they were definitely not walls, just casual means of discouraging soil erosion.

Continuing analysis of these high resolution images in 2014 and 2015 have revealed many more terrace complexes that local officials and preservationists missed  in Union, Towns, Jackson, Gwinnett, White, Gilmer, Dawson, Pickens, Cherokee and Lumpkin Counties, GA – plus Meriwether County on the Flint River in west-central Georgia.  Many of these newest discovered terraces had no stone walls at all. They were far too narrow to have been created by 20th century tractors. The US Department of Agriculture under the Roosevelt administration encouraged Southern farmers to construct contoured terraces on slopes of hilly farms. However, these modern terraces look very different. They are 30 to 50 feet wide and have tractor access at each level.

Itza terrace complexes in the Chiapas Highlands

At this point I dug deeply into the cobwebs of my mind back to the time that I was backpacking through the highlands of Chiapas State and Guatemala. To be very honest with you, my only interest in the agricultural terraces was esthetic. I was an architecture student and these terraces obviously would never have any relevance to my career. Most of the color slides that I took were of large terrace complexes with stone walls and the ruins of temples on top.

Fortunately, they looked just like the Track Rock Terrace Complex.

However, when delving through old slides, I suddenly remembered that most of the actively cultivated terrace complexes had very few stone walls. They had the small streams on either side like the Track Rock Terraces, but the terraces were either all dirt or else buttressed with logs. So the all dirt terraces were merely what was left after log retaining walls had rotted away. Below is a typical appearance of a modern Maya terrace farm near Lake Atitlan, Guatemala. Those are beans growing on the terraces.

This site even has the ruins of temples and a plaza on top, just like Track Rock Gap. Note that two small streams and ravines parallel the terraces- also like Track Rock.
Log walls improve fertility
A contemporary Itza Maya terrace farmer
A contemporary Itza Maya terrace farmer
Out of necessity, all of my original terraces at the experimental garden were supported by logs cleared from the forested hill side where the terraces were excavated by hand. It was slash & burn agriculture in its purest form.

View of the magic garden in April 2015
View of the magic garden in April 2015

However, when I learned that a documentary for public television was to be filmed in my garden, I intentionally built a stone wall along one major terrace, so the film crew would have something to film that looked like the Track Rock Gap terraces. They were also denied access to the Track Rock Terrace Complex. That year the only crops that did well on the stone-walled terrace were members of the squash and pumpkin family. They like hot, well-drained soil. On the other hand the beans, peas and tomatoes were stunted.

A load of charcoal is being worked into the garden soil in early spring.

A load of charcoal is being worked into the garden soil in early spring.
There is another plus to timber walls that I didn’t think about in 2012. By the fourth season, all of the original timber walls have rotted, turning into rich, saw-dust like loam. During the past two years, my crowder peas, sugar snap peas and black-eyed peas (all legumes) have grown 12 feet high. They would have grown higher, but the bean poles were too unstable after that length, so I snipped the ends.

Another riddle about the Track Rock Terrace Complex has been solved by the experimental terrace garden. If you recall in my book, I could not understand why the builders at Track Rock expended so much labor to build terraces, when there were ample stretches of river bottom land within walking distance to the north and the south of the terraces. In fact, these bottom lands contained conventional Muskogean towns with platform mounds that were founded exactly in the same era as Track Rock.

The answer is that maize (Indian corn) loves river bottom lands, but is anemic on terraces facing the southwest. After the second year, I gave up trying to grow corn because it was stunted and the cobs, barely had enough kernels on them to eat. What I do now is trade my surpluses in tomatoes, winter squash and fordhook lima beans for roasting ears, grown by neighbors in stream bottomlands. I strongly suspect that the occupants of Track Rock Gap has a similar arrangement with their neighbors. Now we know!

Below are LIDAR images of small terrace complexes at the edge of Northeast Metro Atlanta, plus an infrared image of a terrace complex near Coosa Bald Mountain that is about 6 miles southwest of Track Rock Gap.

Small terrace complex with a U-shaped plaza on right and a hill rising up behind it with the stone ruins of a prominent building – all features found at the Track Rock site.
Larger terrace complex overlooking North Oconee River.
Larger terrace complex overlooking North Oconee River.
Infrared image of very large terrace complex, about 6 miles southwest of Track Rock Gap.
Infrared image of very large terrace complex, about 6 miles southwest of Track Rock Gap.  This infrared spectrum picks up more fertile soil in steep terrain, covered with shrubs.

Richard Thornton is a professional architect, city planner, author and museum exhibit designer-builder. He is today considered one of the nation’s leading experts on the Southeastern Indians. However, that was not always the case. While at Georgia Tech Richard was the first winner of the Barrett Fellowship, which enabled him to study Mesoamerican architecture and culture in Mexico under the auspices of the Institutio Nacional de Antropoligia e Historia. For decades afterward, he lectured at universities and professional societies around the Southeast on Mesoamerican architecture, while knowing very little about his own Creek heritage. Then he was hired to carry out projects for the Muscogee-Creek Nation in Oklahoma. The rest is history. Richard is a member of the Kaweta Creek Tribe and the Appalachian Shawnee Tribe. In 2009 he was the architect for Oklahoma’s Trail of Tears Memorial at Council Oak Park in Tulsa. He is the president of the Apalache Foundation, which is sponsoring research into the advanced indigenous societies of the Lower Southeast. He is also the National Architecture columnist for the Examiner.

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