Wednesday, January 07, 2015

Chert Debitage as Evidence of Forest Burning

From: Shaping the Forest with Fire-A Very Old Native American Practice
    “When did Native American ancestors begin to use fire in order to clear-out the underbrush, encourage new plant growth, or make clearings?" writes Edward V. Curtin.
      He goes on to say, "The archaeological investigation of Kampoosa Bog near Stockbridge in western Massachusetts also has produced evidence of ancient forest burning, with strong circumstantial evidence that ancient Native Americans were responsible for the fires…
      As Johnson (1996:19-22) relates, there was also some archaeological evidence from chert debitage (the waste material from making tools from the fine grained stone, chert).  The patterns with which chert suffered heat damage, and the locations where heat-damaged chert was found provided important information.  In making stone tools, chert is fractured in a carefully controlled way into relatively flat pieces of debris, or “flakes”.  Flakes have two sides, referred to as dorsal and ventral faces or surfaces.  The dorsal surface is exposed to the environment before the chert flake is detached from a larger core or object that is on the way to becoming a stone tool.  The ventral side is the interior stone part of the stone; it is only exposed after the flake is detached from a larger object.  Since the majority of the flakes were found away from hearths (where accidental burning could have occurred), and because the ventral surfaces often were heat damaged, Johnson reasoned that the flakes were widely dispersed on the ground when fires swept over the ground surface… he inferred that the widespread occurrence of the heat-damaged chert flakes provided evidence of forest burning that had affected artifacts from earlier occupations of the area.  Archaeological surveys and excavations at these sites indicated earlier occupation between 4,000-6,000 years ago; but an apparent intensification of human use occurred 3,000-4,000 years ago, about the same time as evidence of increased forest burning that had been obtained from the bog sediment core samples..."
(The two original drawings appeared here once:

With increased burning, would the need for better control of those fires lead to lead to the building of rows of stone that in part serve as fuel breaks, a very different and much longer "Golden Age of Stone Wall Building" than you might read about in any of a great number of works about stone walls.

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