Thermoluminescence | physics | Britannica
Glycymeris shell beads found in Middle Palaeolithic sites are understood to be artifacts collected by modern humans for symbolic use. In Misliya Cave, Israel, dated to — ka BP, Glycymeris shells were found that were neither perforated nor manipulated; nevertheless, transportation to the cave is regarded as symbolic. In about ka BP at Qafzeh Cave, Israel, modern humans collected naturally perforated Glycymeris shells also for symbolic use. Use-wear analyses backed by experiments demonstrate that the Qafzeh shells were suspended on string, thus suggesting that the collection of perforated shells was intentional. The older Misliya shells join a similar finding from South Africa, while the later-dated perforated shells from Qafzeh resemble other assemblages from North Africa and the Levant, also dated to about ka BP. We conclude that between ka BP and ka BP there was a shift from collecting complete valves to perforated ones, which reflects both the desire and the technological ability to suspend shell beads on string to be displayed on the human body. Editor: Michael D.
Looking at Art, Artifacts and Ideas
Potassium-Argon Dating Potassium-Argon dating is the only viable technique for dating very old archaeological materials. Geologists have used this method to date rocks as much as 4 billion years old. It is based on the fact that some of the radioactive isotope of Potassium, Potassium K ,decays to the gas Argon as Argon Ar By comparing the proportion of K to Ar in a sample of volcanic rock, and knowing the decay rate of K, the date that the rock formed can be determined. How Does the Reaction Work?
Click on a hyperlink to view the corresponding slides. Click the Speaker button to listen to the audio again. Key Events As you read, look for the key events in the history of early humans and the beginnings of civilization. Click the mouse button or press the Space Bar to display the information. The Impact Today The events that occurred during this time period still impact our lives today.