A 1,000-year-old sandstone trench in Colorado's Mesa Verde National Park was used for ritual ceremonies, instead of water storage like previously believed, a new study from U.S. Geological Survey researchers found.
The structure, nicknamed "Mummy Lake," was thought to have been an Ancestral Puebloan water reservoir that was built around 900 A.D. and transported water to surrounding structures, Live Science reported Tuesday. But upon closer inspection of the lake's climactic, topographic and sedimentary features, scientists discovered the trench was not suitable for water transport. They concluded it was really a ceremonial structure built by the Puebloan civilization that lived there, Live Science reported.
"The fundamental problem with Mummy Lake is that it's on a ridge," Larry Benson, a U.S. Geological Survey research scientist, told Live Science.
"It's hard to believe that Native Americans who understood that landscape and were in need of water would have decided to build a reservoir on that ridge."
Officially named Far View Reservoir, the trench was originally 90 feet across and 22 feet deep. Several canals leading out from the ditch were thought to have connected rain water to other parts of the ancient village for farming and drinking.
Yet the canals did not have walls to guide the water along. Scientists found that without them, it would have been impossible for the water to be transported without spilling over the sides, Live Science reported.
Scientists also looked at how well the reservoir- which was never a real lake- could store water. The results showed the trench would not have been able to collect more than a foot of rainfall from winter and spring by April's end. All of the water would have evaporated by July.
Benson and his team realized the surrounding canals were similar in structure to ceremonial roads built by the Chacoan civilization, which built the same roads in other areas in the San Juan Basin, Live Science reported. The trench is also similar to the design of a Pueblo ceremonial kiva room found at the Pueblo site near Zuni, New Mexico.
"I think [the structure] needs a new signage," Benson told Live Science. "We could probably call it 'Mummy Lake' again."
