Distribution of Artifacts By Natural Means
Occasionally archeologists encounter stray arrow points or spear heads on sites which are apparently not indigenous to the area in which they are found. The most frequent explanation of such sports are that they are "trade pieces". No doubt many specimens were transported by primitive traders from one tribe to another over long distances, but this explanation does not cover all aspects of the situation.
"Distribution of Artifacts By Natural Means,"
Bulletin of the Southern California Academy of Sciences:
Available at: https://scholar.oxy.edu/scas/vol40/iss1/4