Friday, August 15, 2008

Middle Field Prehistoric Site

While we were collecting the plowed fields south of town, I noticed what appeared to be different lithic choices between the aboriginal peoples who occupied the Middle Field site and those who lived on sites in the other fields. Specifically, I noticed that many of the flakes and stone tools that we collected in the South Field were quartzites (metamorphosed quartz) of a pinkish or yellowish brown hue, while virtually all of the flakes recovered from the Middle Field (see map below) were white quartz.

Detail map of the Middle Field focusing on the prehistoric site.

Here's a breakdown of the flake types and materials for the Middle Field:

  1. Quartzite 2 Secondary
  2. Quartz 4 Shatter
  3. Quartz 8 Secondary
  4. Quartz 13 Primary
  5. Quartz 21 Decortication
  6. Chert 1 Core

Decortication flakes are those that retain portions of the cortex, or rind, of a pebble before it is broken. Primary flakes are generally large, rectangular, relatively flat flakes from which the stone tool maker (knapper) expected to make a tool. Secondary flakes are attempts to thin the blade of the tool. Typically they are trapezoidal and are curved. Tertiary flakes are small secondary flakes and result from sharpening the edge of a tool. Shatter are those flakes that cannot be classified because they were broken beyond recognition during knapping or long afterward by plowing and other activities. A core is a pebble whence the knapper removes primary flakes.

We didn't find any tertiary flakes (they are difficult to see, although we find them elsewhere). What we did find points to the collection of quartz pebbles from the stream and on-site manufacturing of stone tools, but not re-sharpening which probably occurred when the occupants of the Middle Field site moved elsewhere, bringing their tools with them.

The near absence of quartzite is interesting because it appears that both quartz and quartzite pebbles were locally available and probably occur in the streambed together. Why did the people living on the Middle Field site select quartz while the occupants of some of the other sites prefer quartzite, primarily of a pinkish or yellowish brown color? Was there some kind of significance attributed by some peoples to the quartzite or the colors it exhibited?

The samples, based on surface collections, are too small to say anything definitive, but future testing on the prehistoric sites south of town will take into account these differences and aim at determining if the occupants of these sites were different from one another. Colors have important spiritual significance in many American Indian cultures, present and past. Selection of material on the basis of color could suggest that one aboriginal group moved into an area already occupied or recently abandoned by another. Or it could indicate a shift in beliefs of a single group, with or without outside influence.

In future blogs I'll look at the distribution of lithic material types for the other sites.


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