Sidestep: Distinguishing Artifacts from Ecofacts
How do we know when a rock is a tool?
Here are some common comments and questions relating to debatable artefacts
"Those look like rocks!"
"How can we tell they are actually tools?"
"How can they tell how old the tools are?"
Methods are needed to distinguish human-manufactured stone tools (actual artifacts) from natural rocks (called ecofacts). This is especially important at sites where the methods used to make them is rudimentary. Old Kenyan sites are just one example. These are prehistoric sites...cavemen, if you will.
What are the attributes of a tools which are considered to appear more commonly on artifacts rather than ecofacts. Usually it is intentional creation rather than an accidental creation. One could smash rocks until something usable appears. One could actually reform a basic shape to intentionally produce a usable tool. These attributes include...
Flakes of a similar size
flakes oriented and overlapping forming an edge
bulbs of percussion indicating strong short term force rather than long term pressure
platform preparation
small flakes along the edge showing a flint knapper preparing and edge;
stone type selection
use wear on edges, among others
If you tested known artifact samples, known ecofact samples and a test sample and compared the frequency of these attributes to determine if the test samples were more similar to artifacts or ecofacts you would discover a clear way to differentiate stone tools from naturally occurring rocks.
On the left below are broken pieces of rock. It may be true they were broken off by a human, but even if that were the case they have been abandoned. I have found may such shaped rocks. They were not artefacts nor tools. To the right it is a verified unformed artefact. The difference could not be clearer...especially within NZ with stone items on the surface of the ground where volcanoes, earthquakes, changing sea levels and time had transformed the landscape. Considering 'stone age' tools are hundreds of thousand of years old, the answer isobvious in that fact alone...maybe not so in Africa.
The point being that we can see things within things that are not there - but we want to be there. Wishful thinking does not make something a fact. That does not mean that those that think something is nothing are right either - after all, the absence of evidence does not mean evidence of absence (by default). At times it takes a skillful eye to see what is there, where most would miss it completely. Consider the 7 criteria for examining an artefact (as listed above) and apply those criteria to the above two photos.
Examine the three below with the same criteria...
Now check out a Maori argillite source site below. Stone is purposely struck and chipped and flakes scatter the ground of another site. This is how tools were make long before the Polynesian or Melanesian's arrived. There was intention and purpose involved.
We must be careful not to get carried away with a shape that is a random rock in the hope it is something it is most likely not. Below is a rock found on the ground, and then a very old damaged adze with a perfectly polished blade surface found beneath a skeleton in the far north. The difference could not be more obvious - not just the fact of location...
We wonder what unusual object or artefacts we might find inside the cave? Anything unusual and never before seen would cement our find in history...but as we have always said...we do not doubt any longer but we cannot 'prove' anything yet.
