They do this at a constant rate called an isotope’s “half-life”.
Most carbon comes in the stable forms of carbon-12 (six protons, six neutrons) or carbon-13, but a very small amount (about 0.0000000001%) exists as the radioactive carbon-14 (six protons, eight neutrons).
But he adds: “I’d be more comfortable if there were more of these engraved stones; if these alleged symbols were found many times in different places.
It is possible they were just doodlings that really didn’t mean anything.” Archaeological finds worldwide have helped researchers to fill out the story of human evolution and migration.
Blombos Cave has been inhabited off and on by humans for at least 140,000 years, but the ochre-paint studio seems to have been active about 100,000 years ago.
Prior to the new discovery, the earliest known ochre-making workshop was 60,000 years old, Henshilwood said.
An essential piece of information in this research is the age of the fossils and artifacts. Here are more details on a few of the methods used to date objects discussed in “The Great Human Migration” ( In a cave in Oregon, archaeologists found bones, plant remains and coprolites—fossilized feces.
“The engraving itself is quite a complex geometric pattern.
The discovery is also proof that early humans were capable of long-term planning and had at least a rudimentary knowledge of chemistry, according to the study authors.
“They seemed to know that seal bone is really rich in oil and fat, which is a critical component in making a paint-like substance,” Henshilwood said.
The researchers believe that the ochre was first scraped and ground to create flat surfaces.
It was then marked with cross hatches and lines to create a complex motif.