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TOP:^COURTESYOF^ ELLERY^ FRAHM;^ NATIONAL^ PARK^ SERVICEat the site — and relative dating methods, such as
the age of the layer of sediment in which it was found.
TRACKING ANCIENT TRAVEL
As groups of hunter-gatherers moved across pre-
historic landscapes, collecting obsidian and leaving
behind flakes of it after making or resharpening tools,
they created maps of their movement that archaeolo-
gists can follow with ever greater precision.
Tracing the paths obsidian traveled with early
humans, says Frahm, can reconstruct how people
“made use of their surroundings and met their sub-
sistence needs through mobility across the landscape
and connections with other groups.”
In 2018 in Science, for example, Zipkin and col-
leagues published a trio of papers about finds,
including obsidian artifacts, at the Kenyan site
of Olorgesailie. The obsidian pieces, more than
300,000 years old, came from multiple flows up to
70 miles away: a distance significantly greater than
the average territory of hunter-gatherer groups. This
means that the obsidian collectors may have either
traveled into another group’s territory or traded with
them for the material. Both scenarios suggest that
humans were cognitively capable of complex social
interactions and planning long-distance expeditions
more than 200,000 years earlier than once thought.
Obsidian continues to tell us more about not only
ourselves, but our closest evolutionary kin.
In February, for example, in the Journal of
Archaeological Science: Reports, researchers described
obsidian artifacts up to 73,000 years old, made of raw
material from the Baksan River valley. The location
is the only known obsidian source in the Northern
Caucasus — part of a rugged stretch of mountainous
land straddling southern Russia and the Republic of
Georgia.
The artifacts were found at sites up to 150 miles
from Baksan and, based on style, were made by dif-
ferent, culturally distinct groups of Neanderthals. It’s
the latest blow to the idea that Neanderthals were
less mobile and less capable of networking than early
modern humans.
Ekaterina Doronicheva, lead author of the paper
and an archaeologist at the Laboratory of Prehistory
in St. Petersburg, Russia, says the Baksan obsidian
source was probably a zone of contact between dif-
ferent populations: “We can assume the existence of
cultural contacts between these regions... and that
local Neanderthal groups were part of developed
social networks.”
As technology improves and archaeologists turn up
additional sites, obsidian will remain the glass through
which we see our deep history.
“It’s a bit like being Sherlock Holmes,” says Frahm.
“We are trying to wring every last bit of information
out of these objects that were simply tossed aside
in the past.”^ DGemma Tarlach is senior editor at Discover.ORIGIN STORY
An obsidian
outcrop in Armenia
(above) provided
raw materials for
tools found nearby;
artifacts (below) from
Alaska’s Gates of the
Arctic National Park
were sourced from
about 125 miles away.