The oldest known abstract drawing by a Homo sapiens has been found in South Africa's Blombos Cave, on the face of a flake of rock dated to 73,000 years BP. It is a crosshatch of nine lines, traced with a piece of ocher. The work is at least 30,000 years older than the earliest previously known abstract and figurative drawings executed by Homo sapiens using the same technique. The drawing was a surprising find by archaeologist Doctor Luca Pollarolo, an honorary research fellow at the University of the Witwatersrand.
     Blombos Cave has been excavated by Professor Christopher Henshilwood and Doctor Karen van Niekerk since 1991. It contains material dating from between 100,000 to 70,000 years ago - the Middle Stone Age - as well as younger, Later Stone Age material dating from beteen 2000 and as recently as 300 years ago.
     Under the guidance of Professor Francesco d'Errico at the University of Bordeaux, the team examined and photographed the piece under a microscope to establish whether the lines were part of the stone or applied to it, and also examined the piece by using spectroscopy and an electron microscope. Experimenting with various techniques, they found the drawings were made with an ocher crayon or pencil, with a tip of between 1 and 3 millimeters. The abrupt termination of the lines at the edge of the flake suggested that the pattern originally extended over a larger surface, and may have been more complex.
     Professor Henshilwood: "Before this discovery, Palaeolithic archaeologists have for a long time been convinced that unambiguous symbols first appeared when Homo sapiens entered Europe, about 40,000 years ago, and later replaced local Neanderthals. Recent archaeological discoveries in Africa, Europe and Asia, in which members of our team have often participated, support a much earlier emergence for the production and use of symbols."
     The archaeological layer in which the Blombos drawing was found also yielded other shell beads covered with ocher, and pieces of ocher engraved with abstract patterns, some of which closely resemble the one on the stone flake.

Edited from Popular Archaeology (12 September 2018)