The researchers found that tools salted on ground saturated with water and trampled by buffalo moved up to 21 centimeters vertically, or a little more than 8 inches. Tools trampled by goats moved up to 16 centimeters vertically, or just over 6 inches.
"A vertical displacement of 21 centimeters in some cases might equal thousands of years when we try to figure out the age of an artifact," Eren said. "This amount of disturbance is more than any previously documented experiment and certainly more than we anticipated."
A new "diagnostic marker"
Unfortunately for archaeologists who study the Stone Age, artifacts left behind by prehistoric humans do not stay put, said Eren. Over thousands or even millions of years, all sorts of geological or other processes can move artifacts out of place, he said.
The movement distorts the cultural and behavioral information that is contained in the original artifact patterning, what archaeologists call "context." Archaeologists must discern whether artifacts are in their original context, and thus provide reliable information, or if they've been disturbed in some way that biases the interpretation, said Eren, a graduate student in the SMU Department of Anthropology.
Given that artifacts embedded in the ground at vertical angles appear to be a diagnostic marker of trampling disturbance, the researchers concluded that sites with water-saturated sediments should be identified and reanalyzed.
|Contact: Margaret Allen|
Southern Methodist University