The beads were found at Blombos Cave in South Africa
in archaeological layers dated between 75,000 and 72,000 years ago, during a time period marked by four distinct layers of artifacts called the Still Bay tradition.
If you can pick a moment when you're not having to reconstruct your child's homework
from archaeological layers of papers in their room, it might help, by the way!
The cave, which has
many archaeological layers spanning 100,000 years, has yielded both Neandertal and modern human stone tools and a small collection of hominin bones too fragmentary to be identified.
There, the bone fragments of large salmon, migrating from marine water to their freshwater spawning places, were found in the Middle
Palaeolithic archaeological layers, dated to around 42 to 48,000 years ago, and probably deposited by Neandertals.
One of the more impressing works is Pierre Huyghe's transformation of a closed down ice rink into an eco-system complete
with archaeological layers, peacocks, and beehives.
Around 30,000 years ago, the roof of the cave collapsed and sealed
the archaeological layers until the 21st century.
Years of further excavation has led to a much clearer understanding of the order of
archaeological layers.
The study concludes that
the archaeological layers at the site are so mixed up that ornaments and tools once attributed to Neandertals could actually be the work of modern humans, who lived in the same cave at a later date.
Pinhasi adds that «many of the very young dates, for example, from Gibraltar, are probably just wrong» due to contamination, mixing of
archaeological layers, and other factors.