The 164-foot-wide
earthwork is the sixth ancestral Wichita "council circle"
discovered in the region
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Drone images show the
location of a council circle found on an ancestral Wichita
site in Kansas. (Images by Jesse Casana, Elise Jakoby Laugier
and Austin Chad Hill)
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Archaeologists using new drone-sensing technology have found evidence
of an enormous, horseshoe-shaped trench hidden beneath a Kansas
ranch, reports Kiona N. Smith for Ars
Technica.
The rounded earthwork, which may be part of the largest
pre-Hispanic settlement north of Mexico, appears to be what's
known as a council circle. To date, notes Bruce Bower for Science
News, researchers have identified five such structures across
22 sites in the area.
Ancestors of the modern Wichita
and Affiliated Tribes lived in what is now southeastern Kansas
between about 900 and 1650 A.D. Per Ars Technica, they lived
in grass-roofed pit houses; hunted bison; and farmed crops like
squash, beans and corn.
Over time, erosion filled the newly discovered earthwork with topsoil,
concealing it from view. But modern sensors can detect subtle differences
in temperature and foliage between the filled trench and the earth
around it. As detailed last month in the journal American
Antiquity, the researchers located the ditch through a combination
of drone surveying and LiDAR, infrared and thermal imaging.
Modern construction and farming have damaged many historic Wichita
sites. Now, study co-author Donald
Blakeslee, an anthropological archaeologist at Wichita State
University, tells Science News, "We apparently have
located the sixth council circle and the only one that has not been
disturbed."
Relic hunters who looted the region in the 1800s gave council circles
their name, but the earthworks' actual purpose remains unclear.
As Science News reports, researchers have previously posited
that the structures served as the site of ritual ceremonies, housed
community elites or offered protection from invaders.
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Aerial view of the site
(Jesse Casana)
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In the new paper, the archaeologists suggest that sites including
the just-detailed trench were part of Etzanoa,
a population center dubbed the "Great Settlement" by Spanish
conquistadors.
Spanish colonizers first encountered Etzanoa in the 1590s, when
an unauthorized group traveled north in search of Quivira, a mythical
city of gold, according to Ars Technica. Though the expedition
ended violently, one survivor managed to return and inform the Spanish
of what he'd seen. In 1601, conquistador Juan de Oñate
marched to the settlement, captured a resident and tortured him
until he revealed the city's name.
Archaeologists first excavated the site of the newly discovered
council circle more than 60 years ago, Blakeslee tells Science
News. But by 1967, they felt that they had discovered all of
the mounds and earthworks located along Walnut River.
Thanks to new technology, contemporary researchers have proven
these predecessors wrong. Led by Dartmouth anthropologist Jesse
Casana, the study's authors used nighttime thermal imaging
to measure how daytime heat dissipated from the soil. The ancient
ditch, which measures roughly 165 feet in diameter and 6.5 feet
thick, is filled with looser soil than the tightly packed prairie
around it; as a result, it holds more moisture and radiates less
heat at night.
Casana and his colleagues identified the ditch as a cooler, darker
horseshoe shape in a warm landscape. They then followed up during
the day with photography and infrared imaging. The team also reviewed
previous aerial and satellite images, spotting the circular formation
in photos taken in June 2015 and July 2017, according to a statement.
Drone surveys "can truly transform our ability to locate sites
and map important features where huge areas have been plowed and
surface traces of houses and ditches are often close to invisible,"
Douglas
Bamforth, an archaeologist at the University of Colorado Boulder
who wasn't involved in the study, tells Science News.
Blaeslee, meanwhile, says he plans to continue exploring the site
with remote-sensing techniques, which will hopefully enable the
team to develop precise targets for future excavations.
About Theresa Machemer
Theresa Machemer is a freelance writer based in Washington DC. Her
work has also appeared in National Geographic and SciShow. Website:
tkmach.com
Etzanoa
Conservancy, Inc
The mission of the Etzanoa Conservancy, Inc is to conserve and secure
archaeological sites and artifacts in Cowley County, Kansas, and
the surrounding area and to support archaeological research, interpretation
and education with an emphasis on Etzanoa, the Great Settlement
of the Wichita Nation encountered in 1601 by New Mexico founder
Don Juan de Oñate, the "Last Conquistador".
https://etzanoa.com
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