Caches of argillite bifaces, which are often referred to as petalas blades, have been discovered across much of New Jersey, eastern Pennsylvania, and other Middle Atlantic states. Some of these discoveries are recent; however, many significant finds were made in the late nineteenth and early twentieth centuries. Some of the these caches have been previously analyzed; however, many have not. This study employs Geographic Information Systems and detailed analysis of these blades to better understand these caches. It examines their distribution, function and meaning. Petalas blades were once thought to be used for the processing of anadromous and other migratory fish. This thesis presents an alternative hypothesis. Although, some of these argillite caches were likely used for the processing of fish (migratory and non-migratory); the evidence gathered in this study suggests that others were not used to this end and were perhaps instead instruments of trade.