3 February 2023 The Future is the Product of the Past

11,000-Year-Old LSU Campus Mounds Are Oldest Known Human-Made Structures In North America

According to new research published in the American Journal of Science, two six-meter (20-foot) high mounds on the campus of Louisiana State University (LSU) are the oldest human-made structures ever discovered in North America.

Using radiocarbon dating, the researchers determined that the construction of the mounds began around 11,000 years ago and was completed over several millennia.

The two large, grassy mounds on LSU’s campus, are among the more than 800 human-made, hill-like mounds in Louisiana, built by ancient indigenous people. While many mounds in the region have been destroyed, the LSU Campus Mounds have been preserved and are listed on the National Register for Historic Places.

“There’s nothing known that is man-made and this old still in existence today in North America, except the mounds,” said LSU Department of Geology & Geophysics Professor Emeritus Brooks Ellwood.

Ellwood and colleagues collected sediment cores from the two LSU Campus Mounds to learn more about them. Layers of ash from burned reed and cane plants, as well as burned osteons, were discovered in the cores. Radiocarbon dating of the layers of material indicates the mounds were built over thousands of years.

The LSU Campus Mounds pictured here are the oldest known man-made structures in North America. Photo: LSU

These findings indicate that the first mound was constructed around 11,000 years ago. Because of a large depression in the ground behind LSU’s Hill Memorial Library, the scientists believe the sediment for the southern mound, dubbed “Mound B,” was taken from there. The mound was built up layer by layer over a few thousand years to about half its current height.

“The layers of reed and cane phytoliths, containing very small numbers of osteons, are indicative of very hot fires,” write the authors. Such infernos would have been too hot for cooking, and are therefore likely to have served a ritual function. “This finding supports the argument that the fires were used for ceremonials or cremations,” continue the researchers.

Tantalizingly, the team was unable to determine whether the osteons were of a human or animal origin. The team said they sought permission to perform DNA tests on the microscopic bone materials found, but were not granted permission by the Native American tribal communities contacted.

Around 8,200 years ago, the southern Mound B was abandoned. Tree roots found in the 8,200-year-old sediment layer indicate that the mound was not used for about 1,000 years. Also around 8,200 years ago, the northern hemisphere experienced a major climate event with temperatures suddenly dropping on average by about 35 degrees Fahrenheit, which lasted about 160 years.

LSU Department of Geology & Geophysics Professor Emeritus Brooks Ellwood led the study that has revealed new information on the LSU Campus Mounds including the discovery of thousands of years old charred mammal bone fragments and a coordinated alignment of both mounds toward one of the brightest stars in the night sky. Photo: Eddy Perez, LSU.

“We don’t know why they abandoned the mounds around 8,200 years ago, but we do know their environment changed suddenly and dramatically, which may have affected many aspects of their daily life,” Ellwood said.

Then, around 7,500 years ago, the indigenous people began to build a new mound just to the north of the first mound. However, this time, they took mud from the floodplain where the entrance to LSU’s Tiger Stadium is currently located, which at that time was an estuary. With this mud, they built the second mound, “Mound A,” layer by layer, to about half of its current height. Mound A contains mud that is saturated with water, which liquefies when agitated. As a result, Mound A is unstable and degrading, which is why it is critical to stay off the mounds to preserve them.

According to the new analyses of the sediment layers and their ages, it looks like indigenous people cleared the abandoned first-built Mound B and began to build it up to its current height before completing Mound A. Both mounds were completed around 6,000 years ago and are similar in height.

According to the researchers, the structures are aligned with a point on the horizon that is 8.5 degrees east of true north. Six millennia ago, the red giant star Arcturus – which is among the brightest stars in the sky – would have risen at this very point.

Study author Brooks Ellwood, “the people who constructed the mounds, at about 6,000 years ago, coordinated the structures’ orientation to align with Arcturus, seen in the night sky at that time,” said.

The two small hills have withstood the test of time, leading the authors to speculate that “the LSU Campus Mounds may represent the oldest known and still intact, human-made structures on Earth.”

The study was published in American Journal of Science

Louisiana State University

Cover Photo: LSU

Banner
Related Post

In Bergama, the City of Greek Gods, the People Kept the Cult of Cybele Alive

25 August 2021

25 August 2021

The figurines of Cybele, the goddess of the fertility of Anatolia, and the presence of sanctuaries unearthed in the Ancient...

Excavations of Aççana Mound, the Capital of the Mukish Kingdom, Continue

16 July 2021

16 July 2021

2021 excavations have started at Aççana Höyük, the old city of Alalah, in Hatay’s Reyhanlı district. The ancient city of...

Archeologists discovered a treasure trove at the bottom of an ancient Roman bathhouse drain near Hadrian’s Wall

1 February 2023

1 February 2023

Archeologists in Carlisle, England, discovered a treasure trove at the bottom of the drain system of an ancient Roman bathhouse...

Remains of the summer palace of Genghis Khan’s grandson, Hulagu Khan, found in eastern Turkey

7 July 2022

7 July 2022

The archeology study team, consisting of Turkish and Mongolian scientists, found important findings in the study carried out to find...

The earliest known depiction of biblical heroines Jael and Deborah was discovered at a Jewish synagogue in Israel

8 August 2022

8 August 2022

The earliest known depiction of biblical heroines Jael and Deborah was discovered at a Jewish synagogue at Huqoq in Israel,...

A Christian monastery, possibly pre-dating Islam, found in UAE

6 November 2022

6 November 2022

A Christian monastery has been discovered on the island of Siniyah off the coast of the United Arab Emirates (UAE),...

Mysterious Handprints Found in the Ancient Mayan Cave

1 May 2021

1 May 2021

In Mexico, home to ancient civilizations such as the Maya, Aztec, and Inca, archaeologist Sergio Grosjean found dozens of mysterious...

Excavation in Larissa finds a Hellenistic era sanctuary

27 November 2021

27 November 2021

The Hellenic Ministry of Culture and Sport reported on Friday the discovery of ancient Greek and Hellenistic era structures at...

Roman mosaic found under the pavement in the narrow streets of Hvar

13 February 2022

13 February 2022

In the Old Town on the Adriatic island of Hvar, Croatia, a Roman mosaic was unearthed beneath a narrow street....

The ashes of 8,000 victims were found in two mass graves near the Soldau concentration camp in Poland

14 July 2022

14 July 2022

Polish authorities said they had unearthed two mass graves near the former Nazi concentration camp Soldau containing the ashes of...

Turkey discovers 11 new major hills near famed Gobeklitepe “Potbelly Hill”

28 June 2021

28 June 2021

Turkey reported on Sunday the discovery of 11 new hills in the vicinity of the renowned ancient site of Gobeklitepe...

Parts of the City of the old city of Ghadames called the pearl of the desert collapsed due to rainfall

28 January 2022

28 January 2022

Some parts of the Old City of Ghadames, located in an oasis about 600km southwest of Tripoli near Libya’s border...

Archaeologists Reveal a Hair Style They Think Was Fashion 2000 Years Ago

19 February 2021

19 February 2021

The small 5 cm figurine found during excavations at Wimpole in Cambridgeshire surprised with its details. National Trust archaeologists and...

Archaeologists discover rare Caanite inscription on ancient ivory comb

12 November 2022

12 November 2022

Israeli archaeologists discovered a rare inscription on an ivory comb that sheds new light on the Canaanite language’s use some...

Israeli researchers have found evidence of cooking fish 780,000 years ago at Gesher Benot Ya’aqov

14 November 2022

14 November 2022

Hominins living at Gesher Benot Ya’akov 780,000 years ago liked their fish to be well cooked, Israeli researchers revealed Monday,...

Comments
Leave a Reply

Your email address will not be published. Required fields are marked *