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ABSTRACTThis paper is a revised and updated version of the keynote speaker address for the Block 2 Session: “Data Acquisition in Surface Texture Analysis” for the Online Workshop on Quantitative Artifact Microwear Analysis (QAMA) organized by TraCEr–MONREPOS–RGZM (November 25, 2021) in Neuwied, Germany. It discusses a number of issues related to the acquisition of surface data for texture analysis, including the transition from experimentation to artifact analysis and the importance of standardization of methods. Specifically, the keynote address focuses on eight sub-topics in relation to method development and standardization: (1) Microscopes and operating systems, (2) Magnification, depth of field, working distance, and field of view, (3) Numerical aperture, (4) Cleaning methods, (5) Number and location of surface measurements, (6) Profile versus area measurements, (7) Multiple measurements in the same location, and (8) Surface replication: molds/casts, surface images, and microCT.

Despite the abundance of lithic debitage at preceramic sites in the Maya Lowlands, these data have rarely been studied in detail. We analyzed the chipped chert debitage from Caye Coco and Fred Smith, two Archaic period sites in the Freshwater Creek drainage of northern Belize, to evaluate strategies of lithic raw material procurement, stone tool production, and tool use. The technological and use-wear analyses of the debitage demonstrate that the sites’ inhabitants procured most of their tool stone from the Northern Belize Chert-bearing Zone (NBCZ) and relied on hard-hammer percussion to produce flakes for use as expedient tools and some crude bifaces and unifaces. Although similar patterns of raw material procurement and tool production are demonstrated at both sites, some differences exist, including bipolar reduction at Caye Coco. Based on use-wear analysis, the debitage at the island site of Caye Coco was primarily used for working wood, shell, and hard contact materials and for digging soil. On the shore at Fred Smith, most use-wear is consistent with working wood, plants, and hard contact materials, as well as digging soil. For both sites, analyses suggest the increasing importance of a horticultural subsistence strategy with reduced mobility and reliance on some cultigens that were locally produced.

•GelSight Max used for topographic measurement of stone tool surfaces and microwear.•Surfaces quantified using height parameters, R2, Das, Srel, RL, Asfc, and Lsfc.•Different stone tool surfaces were discriminated over multiple area-/length-scales.•Used and unused tool surfaces were discriminated over multiple area-/length-scales.•GelSight Max limited by gel membrane structure and lower vertical resolution.

ABSTRACTExcavations at Crawford Bank in Crooked Tree, Belize, exposed a lithic deposit with no associated ceramics. The deposit primarily consists of chipped chert and chalcedony tools and debitage, as well as a small number of worked slate fragments. Most of the chert likely sources to the Northern Belize Chert-bearing Zone (NBCZ). The recovery of two Archaic period formal tools – a Lowe point and a constricted uniface/trimmed macroblade – suggests a pre-Maya occupation. Use-wear analysis of both tools and debitage demonstrates a wide range of uses with a focus on wood and hard contact materials. The use-wear patterns demonstrate a heavy reliance on ad hoc/expedient technology for the completion of different tasks involving wood by preceramic peoples. The Crawford Bank site likely represents one or more short-term, task-orientated preceramic occupation(s) for the extraction and use of the available resources of the local wetland environment, most notably logwood.

The application of micro- and nanotechnology, adopted from engineering and materials sciences, is proving valuable in studying stone tool surfaces. Measurement systems for surface characterization have been coupled with parameters that allow for the mathematical characterization of stone tool surfaces. For this project, a Sensofar S neox imaging confocal microscope (ICM)/focus variation microscope (FVM) and an Olympus LEXT OLS4100 laser scanning confocal microscope (LSCM) are used to mathematically document the edge cross-sections on five chipped stone tools made from basalt, chert, obsidian, and quartz. Based on the surface documentation of edge cross-sections, a new algorithm for the calculation of edge curvature at multiple scales is tested. Results indicate the confocal systems experience difficulty documenting edge cross-sections. However, focus variation microscopy can mathematically document edge cross-sections on stone tools made from basalt and chert, thus permitting the calculation of edge curvature over multiple scales of measurement. Microscale documentation of edge cross-sections and calculation of edge curvature will be helpful in understanding the relationships between tool edges, edge sharpness, edge attrition, and microwear. Comparisons between these three measurement systems (ICM, LSCM, FVM) provide information necessary for further method development in edge cross-section measurement and the potential to generate more robust edge analysis protocols.

Stemp et al. (2016) published data on 81 preceramic (Archaic) points from Belize, Central America. In this comment, we report four more chipped chert bifaces recently recovered in Belize (Figure 1). Based on metrics (Table 1), technology, and style, three are classified as Lowe and one as a Sawmill point (Kelly 1993; Lohse et al. 2006; Stemp et al. 2016).

When recovered from ritual contexts at ancient Maya sites, obsidian blades are frequently viewed as blood-letters used for auto-sacrifice. Most evidence supporting this interpretation is circumstantial and derives from iconographic and ethnohistoric sources. Such a deductive approach does not provide a means to determine whether individual blades were used to let blood. In contrast, microscopic use-wear analysis of lithic artifacts can be used to examine blades for evidence of their use, and—provided comparative experimental data are available—to determine if they were blood-letters. The technological and use-wear analyses of 48 obsidian blades recovered from a Late Classic (c. 550–650 CE) dedicatory cache at the site of Pook's Hill, Belize, serve as a test case to explore the relationship between obsidian blades and ancient Maya auto-sacrificial blood-letting. The results of the analyses indicate that some blades from the cache may have been used to let blood; however, not all obsidian blades appear to have been used in the same way. The obsidian blood-letters recovered from the cache were used in cutting, piercing, and piercing-twisting motions. Although some blades were used to let blood, the edge and surface wear on most of the used obsidian blades are consistent with other functions, including cutting meat/skin/fresh hide, cutting or sawing wood and dry hide, cutting or sawing other soft and hard materials, and scraping hard materials. Clearly, not all blades from this ritual deposit were blood-letters, which raises questions about the manner in which such a ritual deposit was formed and the nature of ritual activity associated with caching behavior at Classic period Maya sites.

ABSTRACTTechnological, metric, and microscopic use-wear analyses of the chipped chert and obsidian artifacts from the Chaa Creek chultun present a complex use-history in this underground space. Most, if not all, of the lithics are secondary refuse deposited at this location from other areas of initial production and use. The lithic sub-assemblages within the chultun represent at least two discrete deposition events of expediently produced flakes of local chert used for various domestic/household tasks. The lithics from the construction core of the platform on the surface appear to be secondary refuse that is the product of different formation processes. The number of large whole chert flakes with use wear resulting from contact with wood and stone from the platform construction core suggests an origin from a location or locations in which crafting occurred. By focusing on the stone tools from discrete stratigraphic deposits, it is possible to provide more detailed reconstructions of the various episodes of chultun use.

The ancient Maya engaged in complex rituals to communicate with the supernatural world of gods and ancestors. Among the most important of these rituals was auto-sacrificial blood-letting. Blood-letting was accomplished using a variety of sharp implements, including bone awls and needles, stingray spines, thorny ropes, and obsidian blades. Our understanding of the importance of auto-sacrificial blood-letting to the Maya and the means by which it was done are primarily based on the recovery of material culture from ritually significant contexts, hieroglyphic inscriptions, iconographic representations produced in various media, and Spanish ethnohistoric documents. Based on this information, obsidian blades recovered from ceremonial or ritual contexts, like caches, burials, and caves, are usually assumed to have been blood-letters. Past interpretations of blades as blood-letters have not typically included any use-wear analysis of the blades themselves. This paper presents the results of a microscopic use-wear experiment to replicate one type of auto-sacrificial blood-letting method – piercing using obsidian lancets. In this experiment, seven obsidian lancet replicates and two flake splinter replicates were used to pierce domestic pig skin/flesh 35 times each. The use-wear that developed on the experimental tools would be helpful in identifying suspected blood-letters recovered archaeologically. Importantly, the combinations of wear features observed on the obsidian replicates differed when tools were only pushed into the pig tissue versus when they were pushed into the tissue and rotated. By combining the results of use-wear analyses like those presented in this paper with a consideration of context of recovery, the identification of obsidian blades used as blood-letters by the ancient Maya will be much more likely.

Auto-sacrificial blood-letting was an important ritual practice for the ancient Maya. Letting blood using implements like sharpened bone, stingray spines, thorny ropes, and obsidian blades provided the Maya the means to petition their ancestors and the gods for rain, good harvests, and success in warfare, among other needs and desires. The prevailing assumption is that obsidian blades recovered from ceremonial or ritual contexts, like caches, burials, and caves, were used for blood-letting. This belief is primarily founded on contextual, epigraphic, iconographic, and ethnohistoric information. With some exceptions, however, this interpretation does not typically include any use-wear analysis of the blades themselves. Reasons for the limited application of use-wear analysis to identify obsidian blood-letters recovered from ceremonial or ritual contexts include observational difficulties associated with the minimal wear development resulting from their short term use in this activity and contact with a soft and yielding medium like human flesh. This paper explores an approach to assist in identifying obsidian blades likely used for auto-sacrificial blood-letting based on high-power microscopic (400×) use-wear analysis. The need for this experimental work was initiated by the recovery of some obsidian blades from Actun Uayazba Kab, an ancient Maya cave in Belize, that were suspected blood-letters. Emphasis is placed on the observation and differentiation of wear features produced on 26 experimental obsidian blade segments used to cut pig skin/flesh, as a proxy for human flesh, as well as soft cow hide, fresh pig bone, fresh cohune palm fronds, and queen conch shell. The wear on the suspected blood-letters from Actun Uayazba Kab is similar to that produced on the experimental replicates after very minimal use (30 strokes). Moreover, the combination of wear features on the skin/flesh, hide, bone, plant, and shell can be distinguished from one another even after short-term use.

This pilot study tests the reliability of laser scanning confocal microscopy (LSCM) to quantitatively measure wear on experimental obsidian tools. To our knowledge, this is the first use of confocal microscopy to study wear on stone flakes made from an amorphous silicate like obsidian. Three‐dimensional surface roughness or texture area scans on three obsidian flakes used on different contact materials (hide, shell, wood) were documented using the LSCM to determine whether the worn surfaces could be discriminated using area‐scale analysis, specifically relative area (RelA). When coupled with the F‐test, this scale‐sensitive fractal analysis could not only discriminate the used from unused surfaces on individual tools, but was also capable of discriminating the wear histories of tools used on different contact materials. Results indicate that such discriminations occur at different scales. Confidence levels for the discriminations at different scales were established using the F‐test (mean square ratios or MSRs). In instances where discrimination of surface roughness or texture was not possible above the established confidence level based on MSRs, photomicrographs and RelA assisted in hypothesizing why this was so. SCANNING 33: 279–293, 2011. © 2011 Wiley Periodicals, Inc.

AbstractAlthough considerable progress has been made by archaeologists and materials scientists toward the development of a method to quantitatively document use-wear on stone tool surfaces, experimentation and refinement of methods continue. The experimental program tests root mean square roughness (rms or Rq) of measured profiles for their ability to quantitatively discriminate the surface textures, or roughness, of experimental stone tools used on five contact materials (shell, wood, dry hide, dry antler, and soaked antler). It employs a method for evaluating texture characterization parameters based on their ability to discriminate wear, and to determine a level of confidence for the discrimination, using the F-test. The results of this experiment demonstrate that Rq is not consistently reliable in discriminating measured profiles based on the wear caused by different contact materials on the stone tools.

AbstractUse-wear analysis of the chipped chert and chalcedony tools excavated from San Pedro, Ambergris Caye, Belize, has provided substantial insight into the activities performed by the Maya living at the site from the Classic through Historic periods. The determination of tool action and the materials that were worked by the ancient inhabitants reveals that most activities concentrated on basic subsistence in a coastal environment, with the possibility of small-scale craft-production for local consumption and some regional trade. There is only minor variation in activities undertaken by the San Pedro Maya throughout the lengthy occupation of this site based on the distribution of stone tools with use-related wear.

•Focus variation microscopy used to measure edge angles on stone tools.•Results indicate the edges appear “smoother” at the largest scale of calculation.•Edge shows more detail and appears “rougher” as scale of calculation decreases.•Maximal edge curvature proved reliable at documenting stone tool edges.•Maximal edge curvature on stone tool edges increased with increased use duration.

Obsidian artifacts are commonly recovered as funerary items in ancient Maya burials. Young and old individuals of both sexes and different social classes were buried with different quantities of obsidian, primarily in the form of prismatic blades. Although obsidian blades can serve many functions, those recovered from funerary contexts have traditionally been interpreted as bloodletters. Support for this interpretation has come from ethnohistoric sources, iconography, and the recovery of obsidian blades from locations with similar ritual associations, such as caches and caves. However, based on use-wear analyses it has been demonstrated that not all blades from caches and caves are bloodletters. In this paper we report on the findings of the technological, use-wear, and residue analyses of obsidian artifacts recovered from burials at the ancient Maya site of Pook's Hill, in modern-day Belize. Based on use-wear analysis, three of the blades from the Pook's Hill burials were likely used as bloodletters. Most blades from the burials were used for a variety of other tasks. Moreover, two blades recovered from non-burial contexts at Pook's Hill were used as bloodletters based on use-wear analysis. The results also suggest that the cutting-edge/mass ratio calculated for blades used as bloodletters may serve as a predictor of blade choice for bloodletting.

In the original publication of this article, the title was printed as “Four Preceramic Points Newly Discovered in Belize: A Comment on Stemp et al. (1996:279–299).” The article has been updated to the correct title. The authors apologize for this error.