Portable X-ray fluorescence (pXRF) provides a new alternative to destructive methods of raw material characterization, such as X-ray fluorescence (XRF), neutron activation analysis (NAA), and traditional thin section petrography, although its effectiveness on coarse-grained materials, such as granite, has been questioned. This project addressed this question by determining the effectiveness of pXRF in characterizing granites from Belize and in sourcing granite ground stone tools from Maya sites in Belize. Geochemical fingerprints were defined for three potential source areas (granite plutons in the Maya Mountains of Belize) using outcrop samples. Samples were analyzed using pXRF, XRF, electron microprobe (EMPA), and thin section analyses. PXRF data from archaeological collections of granite ground stone tools from sites in Belize were then compared to the pluton geochemical signatures. There were two principle results of this research. First, analyses indicated that pXRF can accurately characterize the geochemistry of granites from Belize on a suite of elements. Second, this research demonstrated that the Maya of Belize exploited multiple granite outcrops and participated in different kinds of exchange networks to acquire granite, sometimes acquiring stone from the nearest outcrops and sometimes not. While Mountain Pine Ridge was the dominant source outcrop that was exploited, Cockscomb Basin and Hummingbird Ridge granites were also quarried or scavenged. Sometimes the closest source was used, as is the case at Alabama, who exploited the locally available Cockscomb Basin granite. Through this study it appears that the nearest pluton was not always used. Instead Mountain Pine Ridge granite tools were imported from a greater distance, implying that there were additional factors, such as economic partners and changing political powers, which lead to Mountain Pine Ridge granite being the most pervasive in most archaeological collections within Belize.

Often understudied by archaeologists, ground stone tools (GST) were ubiquitous in the ancient Maya world. Their applications ranged from household tools to ceremonial equipment and beyond. Little attention has been focused on chemically sourcing the raw stone material used in GST production, largely because these tools were fashioned out of igneous or sedimentary rock, which can present characterization challenges. And, although portable X-ray fluorescence (pXRF) has been applied widely to source obsidian, the utility of pXRF for geochemically sourcing other kinds of stone remains underexplored. We present a small-scale application of pXRF for determining granite provenance within a section of the Middle Belize Valley in Belize, Central America. Belize is an ideal location to test chemical sourcing studies of granite because there are only three tightly restricted and chemically distinct sources of granite in the country, from which the overwhelming majority of granite for ancient tool production derived. The method described here demonstrates that successful and accurate geological characterizations can be made on granite GST. This cutting-edge sourcing technique has the potential to be more widely applied in other regions to reveal deeper connections between the sources of GST production and sites of consumption across space and through time.

While ubiquitous among ancient Maya sites in Mesoamerica, archaeological analysts frequently overlook the interpretive potential of ground stone tools. The ancient Maya often made these heavy, bulky tools of coarse‐grained, heterogeneous materials that are difficult to chemically source, unlike obsidian. This paper describes an application of handheld, energy‐dispersive X‐ray fluorescence (XRF) to provenance ground stone artifacts (tools and architectural blocks) composed of granite: a nonhomogenous, phaneritic stone. We present a multicomponent methodology that independently tested whole‐rock, thin‐sectioned, and powdered samples by petrographic microscope, conventional, lab‐based XRF, and portable XRF units, which yielded comparable results. After establishing distinct geochemical signatures for the three geographically restricted granite plutons in Belize, we devised a field‐based XRF application on a whole rock that could replicate the compositional readings of lab‐based XRF on powdered materials with sufficient accuracy and reliability. We applied this multishot XRF technique to granite ground stone items from a range of ancient Maya sites throughout Belize; we discuss two specific case studies herein. Our results underscore the widespread potential of multishot XRF applications for determining the provenance of coarse‐grained, heterogeneous rock materials. These results can help push the boundaries from one‐dimensional, functional explanations of ground stone items to their social and ideological dimensions, alongside deeper understandings of granite resource management.

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