Brave sailors to surf the Aegean long before the end of the last ice age.
And all for the sake of the volcanic rocks from which the ancient tools were made and war.
Nikolaos Laskaris of the Aegean University (Greece) and his colleagues, using new technology dating of obsidian found that ships with this valuable cargo sent from the island of Melos (modern. Milos) is already 15 thousand. Years ago. It was located only a large deposit of volcanic glass in the region.
Obsidian is found in a cave in the Peloponnese Franchti - too far from the island. What he melossky, established geochemical examination, but the dating proved a tough nut.
Researchers have turned to this method, as the hydration of the glass, and combine it with a relatively new technique - mass spectrometry of surface saturation in the secondary ions (secondary ion mass spectrometry of surface saturation, SIMS-SS). Both are based on an assessment of the amount of water in the cracks on the surface of obsidian that had accumulated since the breed was extracted from the subsoil.
One glass hydration here you will not manage. Firstly, the microscope can not see how deep into the cracks and how the amount of water every microns, and second, the diffusion front is not where it seems. Dip the straw into the water - and you prividitsya she arched: as we know, water and air a different refractive index. Same thing with obsidian.
SIMS-SS is capable of directly measuring the amount of water in obsidian regardless of the depth of the crack. The particle beam removes ions from obsidian extremely thin layers, like an onion peel.
Thus it was possible to show that obsidian was in melossky Franchti not in the middle of the IX millennium BC. e., but much earlier.