Eerie 'sand burials' of elite Anglo-Saxons and their 'sacrificed' horse discovered near UK nuclear power plant

Archaeologists in the U.K. have discovered a 1,400-year-old burial ground that contains "sand burials" of two elite people and a horse dating to Anglo-Saxon times.

The archaeological team from Oxford Cotswold Archaeology found "at least 11 burial mounds, known as barrows, along with cremation and inhumation burials," they wrote in a statement. The researchers found the burial ground ahead of the construction of a nuclear power plant near the village of Sizewell, which is in the eastern English district of Suffolk.

The site has acidic soil, which tends to degrade bone, but in two graves the outlines of skeletons were found. One grave had the outline of a horse while the other had the outlines of two people. These remnants are known as sand burials, as it looks like the individuals were made out of sand.

The burials, even the horse's, contained grave goods.

"The horse was buried with its tack [riding gear] still on its head and shoulders that comprised [pieces] of copper alloy decoration and a probable iron bit in its mouth," Maria Bellissimo, a spokesperson at Oxford Cotswold Archaeology, told Live Science in an email. The two people "were buried with a sword, a spear, two shields, an iron banded bucket, along with a copper and a silver vessel."

Although the sand burials hold important clues, they don't impart as much information as a preserved skeleton would.

"We cannot tell their age as accurately" from their sandy silhouettes as experts could from a skeleton, Bellissimo said, "but it looks like they were both probably full-grown adults." The sex of the two people is unknown, but "our evidence indicates that the two individuals were buried at the same time and so it's very likely they died at the same time," Bellissimo said.

Their cause of death is also a mystery. "We can postulate that the horse was probably sacrificed to be interred with its owners, who we assume to be the two individuals in the adjacent grave," she said.

They appear to date to the sixth or seventh century A.D., a time when England was divided into several kingdoms. It's not clear who these people were, but the "weaponry, the horse and the copper and silver items within the grave as well as them being buried in a burial mound [suggest] that these were elite individuals," Bellissimo said.

Howard Williams, a professor of archaeology at the University of Chester in the U.K. who was not involved with the excavations, said that the burials are located on a ridge that is "prominent in the local landscape for those travelling inland" after landing at sea. At the time there "were maritime communities connected by trade and kinship along England's east coast as well as connections inland across south-east Britain."

The new discovery promises "to add important information to our understanding of the practices and beliefs of these people who [were] part of the emerging East Anglian kingdom in the centuries after the collapse of the Roman province of Britannia," Williams told Live Science in an email.

Archaeologists made additional discoveries during the excavation. One of them was a hoard of more than 300 silver coins that dates to the 11th century.

Found bundled in lead and cloth, the "hoard is believed to have been a savings pot buried by a local figure as a precaution during a time of significant social and political unrest" in the 11th century, the team wrote in the statement.

What's more, experts identified a pottery kiln dating to the Roman period (A.D. 43 to 410), an oak ladder dating to the Iron Age (800 B.C. to A.D. 50), the remains of settlements from the Bronze Age (2300 to 800 B.C.), as well as numerous ovens from medieval times (600 to 1500). Research into the discoveries is ongoing.