The Sample

Excavations at the Eaton site in western New York State yielded 116 chipped stone tools tentatively identified as perforators and gravers. In turning to the literature, we were unable to find a discussion of the difference between these two tool types. When we sought to compare these specimens with others from sites in the Northeast, we found that systematic data were lacking. These deficiencies in the archaeological database prompted the research presented here.

Eaton is a multicomponent site now owned by the Archaeological Conservancy (Figure 1). Its major component is an Iroquoian village dating to the mid-sixteenth century. A total of 257 2 m² units were excavated by 17 summer archaeological field schools between 1975 and 2000. All soil was screened using quarter-inch hardware cloth, except for samples from features that were subject to flotation. Hundreds of chipped stone tools, including 81 drills and 115 drill fragments (Engelbrecht Reference Engelbrecht2023; Engelbrecht et al. Reference Engelbrecht, Hanrahan and Salisbury2023), and 335,433 pieces of lithic debris were recovered during these excavations. Most of the lithic tools and debris were of Onondaga chert.

Figure 1.

Location of the Eaton site.

The site was plowed from the latter part of the nineteenth century through the mid-twentieth century, and most artifacts were recovered from the plow zone. Post molds delineate the major portions of three Iroquoian longhouses and a portion of a palisade. It is assumed that most stone tools with projections were used during the Iroquoian occupation because the bulk of diagnostic material is Iroquoian.

Of the 116 specimens in this study, 50 were unifacial flakes, six were unifacial blades, 45 were bifaces, and 15 were cores or core fragments. Thirty-three of the bifaces in the sample were damaged or whole projectile points or projectile point preforms that were reworked. Of the 116 specimens, 24 were also morphological scrapers, knives, or both. Five additional specimens that were likely perforators or gravers had a projection or tip snapped off and were not considered in this study. An Access table (available at https://core.tdar.org/dataset/497107/eaton-chipped-stone-perfortors-and-gravers) records the location of every specimen (unit, level, relationship to the longhouses) and various attributes, including maximum length, width, thickness, mass, cross-sectional shape, bit thickness, projection perimeter, and tip angle.

Projection Tip Morphology

The projections/tips in our sample were produced in a variety of ways, including unifacial or bifacial retouch on one or both margins or from a snap or break on one side. The projections on the unifacial specimens were created by the removal of one or two flakes. Chipped stone gravers are assumed to incise, slot, groove, or carve the surface of material, especially medium-hard to hard materials like wood, bone, antler, or stone (Ballin Reference Ballin2021:62; Boen and Williams Reference Boen and Williams2022; Morrow Reference Morrow2016). They need to be sturdy to withstand the pressure of being used on medium-hard to hard materials. Our expectation is that tools with a thick projection and a wide distal angle would be gravers. Perforators are defined functionally as tools used to create holes by pushing or twisting through soft to medium-hard material. Awls and needles made of bone, antler, or even thorns can also be used to perforate soft material. A sharp point is needed to perforate hides because they tend to stretch, rather than break (Hughes Reference Hughes1998:353). As Friis-Hansen (Reference Friis-Hansen1990:497) observes, the narrower the front angle of a projectile point, the more likely it is to penetrate a hide, and we would expect the same for perforators. We expect chipped stone perforators to have a thin projection with a sharp distal angle.

Quinn and colleagues (Reference Quinn, Andrefsky, Kuijt, Finlayson and Andrefsky2008) developed a sharpness index for el-Khiam projectile points from the Near East by dividing the tip into two right triangles and then using trigonometry to determine the distal angle. Taking a series of measurements from the tip, and then averaging them, gives an approximation of the front distal angle. However, projections in our study appear to be both narrower and shorter than those of el-Khiam points, making this methodology less suitable. We decided instead to use a goniometer to measure the angle. A common problem with goniometer measurements relates to the physical interaction between the goniometer, object, and individual (Yezzi-Woodley et al. Reference Yezzi-Woodley, Calder, Oliver, Cody, Huffstutler, Terwilliger, Melton, Tappen, Coil and Tostevin2020). We placed the specimen on top of the instrument, with the tip of the projection at the fulcrum and the stationary and moving arms of the goniometer aligned with the first 4 mm of the lateral edges of the tip. If the lateral edges of the projection were less than 4 mm, we measured the angle of the shorter projection. This ensured that the goniometer arms were on a flat surface. The distal tips were angular, so curvature was not a problem, and the sizes of the specimen and the instrument were compatible.

In addition to the distal angle, we wanted to consider the perimeter of the tip, which we see as relevant to the functions of perforating and engraving. We considered using the cross-sectional perimeter metric for the projection tip, rather than the midsection of a projectile point; we decided, however, that at this smaller scale a direct measurement was more accurate than one based on an idealized geometric form. The perimeter of the projection was measured 4 mm from its tip unless the projection was shorter, in which case we measured the circumference at the base of the tip. To do so, we wrapped dental floss around the specimen: the floss was found to be easier to use than thread, string, or dental tape. One end of the floss was first affixed to a piece of clear tape and then taped to the face of the specimen, with the end of the floss lining up with a lateral edge. While securing the tape with a finger, the specimen was twisted, resulting in the floss being wrapped around the specimen. The floss was pulled taut by its container. We then used manicure scissors to snip the floss along the lateral edge where it met its taped end and then took a linear measurement in millimeters of the segment of dental floss. The perimeter of each projection was measured twice with the same result. This procedure has the advantage of being fast, easy, inexpensive, and accurate.

Use Wear

We chose 30 specimens for use-wear analysis. To ensure a representative sample of projection tip angles and perimeters, we added the angle (degrees) and perimeter (mm) for each specimen and then chose specimens with the following sums: 23, 27, 32, 35, 37, 38, 40, 41, 42, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 56, 59, 61, 63, 65, 67, 69, 73, 76, 78. These represented the range of values, with 23 being a sharp-angled narrow projection and 78 being a wide-angled thick projection. To examine use wear, an AmScope trinocular microscope was fitted with WF 20/10× eyepieces, 2× objective lens, and 1.0×–4.5× zoom objective. Magnification varied between 40× and 180×. Thirteen specimens exhibited wear from perforation and 17 from engraving. However, all 30 specimens had wear suggesting multifunctional use: twisting/drilling, cutting, or scraping. Qualitative and quantitative aspects of the wear observed suggested a higher probability of either perforating or engraving. Recording of wear indicative of other functions—drilling, cutting, or scraping—was typically limited.

Specimens with perforation wear showed a higher incidence of edge serrations, whereas specimens with graver wear exhibited moderate to heavy micro-fracturing with continuous scalar scarring and more intense polish and edge rounding. In general, specimens with perforation wear showed less variable wear on the distal tip and less morphological change than gravers (Figures 2 and 3). Detailed use-wear descriptions of each specimen may be found on tDAR (https://core.tdar.org/collection/71221/eaton-chipped-stone-tool-use-wear).

Figure 2.

Perforator #1609: Use wear includes edge seriation, minor edge rounding, and fracturing; 40× magnification. (Color online)

Figure 3.

Graver #1565: Use wear includes moderate to heavy micro-fracturing along with scalar scarring, edge rounding, step fracturing, and distal edge crushing; 40× magnification. (Color online)

Summary and Conclusion

Chipped stone tools with projections are found worldwide and are given various type names, including perforator and graver. However, one researcher's graver is another researcher's perforator, leading to noncomparable databases. This use-wear study indicates that specimens with perforation use wear have projections that are both thin and sharp, whereas graver use wear occurs on projections of variable perimeters and tip angles. For typological purposes, we advocate that specimens exhibiting a distal angle of 40 degrees or less and a projection perimeter of 20 mm or less be classified as perforators, and those with greater dimensions be termed gravers. We recognize that placing specimens in lithic tool types obscures the variability between them and may lead to false assumptions concerning function. However, the use of a typology does not prevent the investigation of intra-type variation. This is a separate research goal from the comparisons of large assemblages for which the description of individual specimens is not practical. Currently, the failure of archaeologists to use a uniform lithic tool typology for perforators and gravers renders inferences on the use of these tools over broad areas or time periods little more than speculation.