Raw Material Sourcing Study


The sourcing of various types of stone help archaeologists identify where a particular raw material resource occurs naturally. Ideally, prehistoric groups occupied areas where these stone resources were easily available. However, this was not always the case. Sometimes, some materials had to be obtained from quite long distances away and in many cases were highly prized exotic stone. In 2007, the Center for Big Bend Studies (CBBS) launched a geochemical sourcing study to find out where certain stone sources were for the manufacture a variety of stone tools found in the eastern Trans-Pecos/Big Bend region (ETP/BB) and adjacent regions. This is the case for an artifact called a "lunate stone." Lunate stones are crescent-shaped, ground and polished stone artifacts with a series of notches usually present on the dorsal, convex ridge. Lunate stones are often prestigious funerary objects of Late Archaic burials of the Southern Plains of Texas. Most lunate stones are made of "greenstone", obviously obtained or traded from outside the Southern Plains. Many researchers have long thought that this material came from the Davis Mountains in the eastern Trans-Pecos region. Comparative trace element analysis of lunate stone artifacts from the Southern Plains with naturally occurring, greenstone from the Davis Mountains was conducted using the inductively coupled plasma source mass spectrometry (ICP-MS) method. A review of lunate stones and findings of trace element signatures is presented in the CBBS collective papers series. This is the first for sourcing ground and/or polished stone artifacts in Texas.

Native greenstone formation
Artifact made from greenstone