Echoes from the past: Archeologists work at a site where an ancient stone calendar was found.

TUYEN QUANG (VNS)— Archaeologists have found a stone tool assumed to be an early calendar dating back 4,000 years in a cave in the northern province of Tuyen Quang.

The stone tool, with 23 parallel carved lines, seemed to be a counting instrument involving the lunar calendar, Prof Trinh Nang Chung from the Viet Nam Archaeology Institute told Viet Nam News.

A similar tool was found in Na Cooc Cave in the northern province of Thai Nguyen's Phu Luong District in 1985, Chung said. Similar items have been found in various areas in the world, including China, Israel and the UK, suggesting that people 5,000 years ago knew how to calculate the lunar calendar by carving on stones.

The stone tool was found in a tomb marked with 14 large stones laid at a length of 1.6m. Bones were found under the stones but no skull was found, with Chung guessing that the skull may have decayed due to the humidity in the cave.

A number of other stone tools were buried with the corpse, he added.

 

Excavated: This stone tool with carved parallel lines is thought to be an early calendar dating back some 4,000 years. — Photos courtesy of Trinh Nang Chung

The excavation was conducted on a total area of 20sq.m inside Nguom Hau Cave in Na Hang District, unearthing about 400 objects to a depth of 1.2m belonging to two cultural layers of the Late Neolithic period (4,000-4,200 years ago) and the Metal Age (around 3,000-3,500 years ago).

The deeper layer (of Late Neolithic), about 1m thick, consisted of well-polished axes and other stone tools, while the later cultural layer measured only 20cm contains fewer tools with axes and ceramic pieces.

There was also a large amount of animal teeth and shells found at the site, thought to be the remnants of food left by the ancient dwellers. Scientists also found traces of burned coal and fire in both layers.

The cave was discovered in May of last year, while the excavation was conducted within a 20-day period earlier this month.

Earlier excavations in the same province have found traces of human populations dating back to 7,000-8,000 years ago.

"These findings prove that early people have lived continuously in local caves since 8,000 years ago, until more advanced material cultures developed," Chung said. — VNS