Thousands of ancient stone tools made by early humans found in cave

By Stephen Beech

Thousands of stone tools made by early humans around 20,000 years ago have been found in a cave.

The "important" find reveals connections between prehistoric people, say scientists.

Archaeologists made the discovery in a cave overlooking the ocean on the southern coast of South Africa - that was once inland.

They have been able to tell how the tools were made by examining tiny details in the chipped edges of the blades and stones.

Researchers analyzed the stone tools and discussed how the different techniques used to make them hint at the ways that prehistoric people traveled, interacted, and shared their craft.

Their findings have been published in the Journal of Palaeolithic Archaeology.

Study lead author Dr. Sara Watson, of the Field Museum in Chicago, said: “This is an important insight into how people who lived in this region were living and hunting and responding to their environment."

She explained that during the period when the blades were made, between 24,000 and 12,000 years ago, the Earth was nearing the end of the last major Ice Age.

Since so much of the Earth’s water was frozen in glaciers and ice caps, the sea level was lower, and the region that’s now the coast of South Africa was a few miles inland.

Dr. Watson said: “Instead of being right on the water like they are today, these caves would have been near vast, open plains with large game animals like antelope.

“People hunted those animals, and to do that, they developed new tools and weapons.”

The caves, part of what archaeologists call the Robberg technocomplex, no longer overlook a plain, but are instead in a towering cliff face over a rocky beach.

Dr. Watson said: “It’s a 75-foot climb up to the cave from the shoreline.

“We had safety ropes and a staircase made of sandbags, and we had to be harnessed in while doing the excavation.”

Dr. Watson and her colleagues made the daily climb with all their excavation and photography equipment, weighing up to 50lbs (22.6 kilos) per person.

She said: “Since these are extremely, extremely old sites, from before the end of the last Ice Age, we had to be very careful with our excavation.

“We used little tiny dental tools and mini trowels so that we could remove each little individual layer of sediment.”

Beneath ancient dust and dirt, Dr. Watson and her team found thousands of stone tools including small, sharp blades, as well as the larger pieces of rock from which the blades were chipped.

The bigger rock that blades are made from is called a core.

Dr. Watson said: “When your average person thinks about stone tools, they probably focus on the detached pieces, the blades and flakes.

"But the thing that is the most interesting to me is the core, because it shows us the particular methods and order of operations that people went through in order to make their tools.”

She and her colleagues observed several "distinct" patterns of how the cores had been broken into smaller blades.

Dr. Watson said: “In a lot of these technologies, the core reduction is very specific, and it’s something that you are taught and learn, and that’s where the social information is.

“If we see specific methods of core reduction at multiple sites across the landscape, as an archaeologist, it tells me that these people were sharing ideas with one another.”

For example, one particular method of breaking tiny bladelets off of a core that Dr Watson found in the Robberg caves is a style also found hundreds of miles away in locations including Namibia and Lesotho.

Dr. Watson said: “Same core reduction pattern, same intended product.

“The pattern is repeated over and over and over again, which indicates that it is intentional and shared, rather than just a chance similarity.”

Dr. Watson says that the study reveals how much there still is to learn about the Robberg caves and the people who used them thousands of years ago.

She added: “We have a very long and rich history as a species, and humans go back a lot farther in time than most people realize.

“People living around the last Ice Age were very similar to people today.”