Introduction, Project Goal, and Previous Studies
Introduction to the Project and Its Goals
Prehistoric Hopewellian peoples of the eastern United States (ca. 150 B.C. – A.D. 400) are well known for their artworks of copper, which were buried with their dead or in caches within earthen mounds. A systematic, in-depth survey of 320 copper ceremonial plaques, headdresses, and celts from southern Ohio and Indiana indicates that many appear to bear artistic design elements and compositions similar in style to those of known Hopewellian and earlier Adena art in other media from the eastern United States. At the time of the grant application, the apparent artworks were thought to have been made entirely by painting with mineral pigments and by collage with other materials that are unnatural to copper. Chemical and physical materials testing and microscopy suggested these artistic processes. During the course of the grant research, an additional artistic process was documented: the purposeful creation of copper corrosion products patinas. Materials analysis, corrosion modeling, microscopic examination of the copper objects revealed this process, and experimental replication of artistic works verified it.
While it is clear that certain copper objects bear artistic imagery, many are harder to decipher by the naked eye, alone. The purposes of the proposed research have been three: (1) to identify the nature of the materials used to create the copper-based imagery, (2) to identify the artistic processes used to create the imagery, and (3) to develop a systematic, integrated set of digital photographic techniques for effectively recovering, enhancing, and displaying images on Hopewellian (and other) copper artifacts, as one approach to preserving the images and guiding subsequent efforts to conserve them. Initial testing had shown that certain photographic methods were effective, but the range of materials and preservation conditions for which this is true, and the tailoring of specific techniques to given material types, remain to be systematically investigated. In the course of the proposed methodological work, potential images on the items were preserved photographically.
The Archeological Context
The Ohio Hopewell were semi-mobile, apparently swidden horticulturalists and hunter-gatherers (Wymer 1996, 1997) who lived in the major river valleys of southern Ohio between ca. 150 B.C. and A.D. 400. Ohio Hopewellian peoples lived in small homesteads and camps of one or a few households each, which were dispersed over the valleys. Multiple households were probably organized into communities which centered on earthwork-burial mound sites that held their dead (Brose and Greber 1979; Brown 1981, 1982; Carr and Maslowski 1995; Dancey 1991; Dancey and Pacheco 1997; Greber 1979; Greber and Ruhl 1989; Konigsberg 1993; Pacheco 1988; Prufer et al 1965).
Ohio Hopewellian communities appear to have been integrated and regulated in several fashions: (1) ritually by periodic mortuary and other ceremonies, and perhaps feasts, within the earthworks (Seeman 1979; Smith 1992); (2) socioeconomically by local utilitarian exchange (Carr and Komorowski 1995); (3) politically by shaman-like leaders and clan or lineage heads who sometimes impersonated animals (e.g., the deer-”rabbit” impersonator from Mound 25, Hopewell site, Moorehead 1922:128; the Wray figurine bear impersonator from Newark; the decorated stone head from Edwin Harness, Greber 1983:33; see also the earlier raptor-human faces on Adena tablets, Otto 1975; Webb and Baby 1957); and (4) symbolically and ideologically by art and exotic raw materials that apparently were displayed and used by social-ceremonial leaders (e.g., Greber and Ruhl 1989), and that expressed a common, basic world view (Carr 1998, 1999; Seeman 1995).
The Ohio Hopewell are well known for their fine mortuary and ceremonial art, and their procurement of fancy raw materials from distant sources over the continent to make much of that art. Geometric and representational line engravings on animal and human bone, terra-cotta and stone sculptures, and forms created out of copper, silver, meteoritic iron, mica, shell, obsidian, etc., comprise the most common kinds of published art (e.g., Brose et al. 1985; Otto 1992; Penney 1983, 1985, 1989). Archaeological complexes with similar mortuary-ceremonial art occur across the eastern United States from the Great Lakes to the Gulf Coast, and from New York to western Missouri (Griffin 1967:181).
Problem Development and Project Goals
Over the course of 37 weeks during 1995-1997, the PI made complete visual surveys of nearly all extant major collections of Ohio Hopewell and Mann-Phase (Indiana) Hopewell artifacts housed in 12 museums, universities, and private collections in the United States (e.g., The Chicago Field Museum, The Peabody Museum of Harvard University, The Ohio Historical Center, Columbus). The survey was financially supported by the Wenner-Gren Foundation of Anthropological Research, the Chicago Field Museum, and Arizona State University. The purpose of the survey was to find unpublished examples of Hopewellian art. During this work, the PI noticed that many of the 320 extant copper plaques, headplates, and celts, as well as some earspools, pendants, and other copper items, appear to have on them the remains of artistic design elements and compositions that previously had gone undetected. Some images are clear; many are more subtle in their preservation. The items come from at least 15 major mound- earthwork complexes and smaller mound sites in diverse depositional environments.
The content, style, and techniques of production of the apparent images lend them credibility. The images systematically repeat among objects and resemble those found in Hopewellian and earlier Adena art in other media. The images are primarily of apparent animals, humans, or animal-human composites similar to those referenced above. The animal species most frequently represented are raptorial bird, bear, deer, wolf, and cat — species that commonly served as clan totemic animals and names of clans or phratries in the historic northern Woodlands (Trigger 1978). These figures are arranged in compositions that have bilateral or quadripartite symmetry, figure-ground reversal, and complex intertwining of shapes — traits of Hopewellian iconography, generally.
At the time of grant application to NCPTT, the methods by which the imagery appeared to have been made include: painting with mineral pigments, and the application and arrangement of a variety of materials, including cut-out shapes of textiles, bark, ground-up plant material, small segments of plant stems, untwisted plant fibers, cordage, sand, bone, pearls, and feathers. A pigmented, gum or sap-like, possible adhesive had also been observed. In some cases, a fiber-paste layer appeared to have been built up over the copper surface, and then differentially removed to create bas-relief area-fills or to expose the underlying plate so as to create images in the negative.
In retrospect, artistic work of these various kinds on copper Hopewellian artifacts is not unexpected: copper plaques, headplates, and earspools are known to have sometimes been decorated with designs by other, better preserved, sometimes conceptually-related means, including embossing, area cut-outs, and silver and meteoric iron applique’. In addition, a logical chronological development in art on rectangular forms can be found in the shift from Early Woodland Adena stone and clay tablets that were engraved, to early Middle Woodland Hopewellian copper plaques from Mound City that were embossed or cut out, to later Middle Woodland Ohio Hopewellian copper plaques (e.g., from Hopewell, Seip) decorated by painting and material applications. Artworks of all three times share similarities in content and layout (e.g., raptorial birds placed in the four directions/corners), as well as structure (e.g., figure-ground reversal and intertwined figures).
Preliminary Materials Analyses and Development of Digital Photographic Methods
To begin to understand how images were manufactured on the copper objects, to explore their taphonomy, and to assess methods for clarifying the images, two kinds of preliminary studies were made : (1) chemical and microscopic studies of the materials that form the images, and (2) digital photographic and other methods of image enhancement. The studies were made primarily by the team researchers for this proposed project.
Preliminary materials analytical chemical and microscopic studies.
Microsamples of 11 differently colored surface materials — 10 thought to be mineral pigments and one an organic binder or adhesive — were removed from 63 locations on 11 copper plaques, headplates, and celts from four different Ohio Hopewell archaeological sites (depositional and taphonomic environments): Hopewell, Seip, Ater, and Fortney. The samples were taken from areas that are integral parts of likely human or animal images or their contrasting backgrounds, and that appear unnaturally homogeneous in color. The material types of the samples were determined with five complementary physico-chemical methods: (1) electron microprobe analysis using energy dispersive detection, (2) Raman microspectroscopy using 514.5 nm and 785 nm excitation wavelengths, (3) x-ray diffraction using a Debye-Sherer camera, (4) SEM microphotography at 50 – 200X and 3000X, and (5) petrological description under a stereo-zoomscope at 6 – 31X. These methods respectively documented the samples’ elemental compositions, inter-atomic bonding characteristics, crystallographic structure, crystal micromorphology, and crystal habit.
The ten minerals were found to fall into two groups: (1) noncopper compounds that do not derive from copper corrosion and that, from all evidence, appear to be applied pigments, and (2) copper corrosion products that could, on the basis of their chemistry alone, be either applied pigments or in situ developments. The noncopper compounds are red, yellow, white, and brown-black in color — the same colors used in other Ohio Hopewell artwork, the colors of the soils used in contrasting distributions to build some Ohio Hopewell mounds and earthworks, and the colors found in much historic Woodland Native American art and ceremony. The compounds include: (1) hematite; (2) serpentine; (3) probably bone with a small amount of calcite, dolomite, shell, pearl, and/or some other primarily calcium carbonate material; and (4) probably an organic-rich soil. The copper-based compounds are red, aqua, blue-green, turquoise, and deep blue, and include (5) cuprite, (6) chrysocolla, (7) malachite, (8) azurite, (9) turquoise, and (10) perhaps others in minor amounts. The one possible organic binder for the pigments, or adehsive, was found to bubble under the heat of the microprobe electron beam and to be noncrystalline, as expected. It contains red and yellow colorants fully dissolved within it.
The copper-bearing compounds, which form integral parts of images like the noncopper ones, logically could indicate artistry either directly or indirectly. Two hypotheses were investigated during the course of the NCPTT research project. (1) Natural copper corrosion products could have been scraped from native copper, or mined along with native copper at its sources, to form pigments of green, blue, or red, which were then added to some vehicle/binder. Different corrosion-derived paints of different colors could then have been applied to different areas of a composition. (2) Different corrosion products of varying colors could have developed naturally in situ in different images or parts of images because these areas were originally treated with different fugitive substances to form images (e.g., cut-outs or arrangements of organic materials). Areas treated differently would then have posed varying corrosion environments that differed in pH, available elements, and/or water-retention, leading to the formation of different corrosion minerals of different colors in those areas (see Jakes and Sibley 1984:421 for analogous archaeological examples). In this case, the shapes of any images would have been preserved, but their original colors would not have.
A variety of observations by copper corrosion and mineralogy professionals on the research team suggested hypotheses 1 and 2, i.e., that the copper-based minerals from images were either applied as pigments or developed in situ naturally: (1) image areas comprised of chrysocolla, malachite, and azurite and having crisp, regular, linear or curvilinear edges unnatural to copper corrosion growth; (2) apparent “drying lines”– where malachite and azurite seem to have accumulated at the drying edges of an image; (3) colored areas probably produced by the mixing of two copper corrosion pigments, the particles of which are jumbled together and do not grow from the copper substrate; (4)
image areas having apparent copper corrosion pigments that lay on top of applied organic materials and lack development from the copper substrate; (5) celts and plaques with a uniform background color of azurite and with image-areas of turquoise–minerals that mathematical-chemical preliminary modeling showed are not stable compounds in the soil conditions (pH, temperature, water, dissolved ions) of Ohio, and that are not reported as natural, in-situ developed components of the Ohio geological landscape; (6) delaminating layers of possible paints of several colors; and (7) drying cracks of possible paints of several colors. The mathematical-chemical modeling was accomplished with an exploratory construction of some “phase diagrams” of the equilibrium thermodynamics of copper-aqueous systems.
By the end of the project, evidence to support hypothesis 1 had waned considerably, whereas hypothesis 2 was well supported and extended. What had not been anticipated but was observed during the NCPTT research is that the process by which images were created through corrosion was, in many cases, intentional patination by Hopewell artists rather than a byproduct of their artwork in fugitive organics, as in hypothesis 2.
The geological formations from which copper pigments might have been mined, assuming hypothesis 1, has not been determined. However, deposits of chrysocolla, malachite, azurite, turquoise and cuprite occur in the copper-bearing localities of Michigan, Tennessee, Pennsylvania, and/or Alabama (Roberts et al. 1990) — areas exploited by Hopewellian peoples for other ceremonial raw materials and artifacts.
Preliminary Studies of Digital Photography and Image Enhancement Methods
The second kind of study made preliminary to the NCPTT-supported research aimed at assessing digital photographic and image enhancement methods for clarifying the images that appeared to have been rendered on the copper artifacts. This section necessarily begins with two literature reviews before proceeding to discuss the preliminary analyses that were made.
Literature Review of Digital Photography. Digital imaging of the kind applied in this project involves the detection of multiple, distinct bands (fequencies) of visible and/or infrared light within each of a large matrix of cells (pixels) within a viewing area. Such digital imaging has a long history in the fields of remote sensing by satellite and aerial photography (American Society of Photogrammetry 1968,1983, 1984; Castleman 1979; Pratt 1978; Gonzalez and Wintz 1977; Lilles and Kiefer 1987). However, only in the past several years have color digital cameras with the fine resolution, compact size, and reasonable cost that is required in archaeological and museum analytical work become available. Thus, such applications have been few in these fields. Digital photography is now used in some museums (e.g., American Musuem of Natural History) to make permanent, nondeteriorating records of irreplacable objects that are subject to degradation, loss of ownership, or repatriation. Davis and Steponaitis (1996) used digital photography for this purpose and to provide concerned Native American tribes with visual records of burial goods housed at the University of North Carolina. Bearman (1996) used a digital camera with near-infrared sensors to photograph portions of the Dead Sea scrolls in preparation for enhancing the writing on darkened, unreadable portions. One of the earliest applications of digital photography to archaeology was made underwater. An electronic still camera with direct digital output, which allowed the operator to preview images, was used to document the U.S.S. Hamilton, which sunk in Lake Ontario during the War of 1812 (Stewart 1991).
In art history, infrared (IR) photography using a digital camera with sensors of infrared waves, or infrared-sensitive film, has been used commonly to view underdrawings below a painting’s surface, to view layers of painting over painting, and to pinpoint areas of aging and damage on artworks (e.g., De Boer 1970; Desneux 1958; Dunkerton et al 1987; McKim-Smith 1988; Panofsky 1958; Roy 1988; Marijnissen 1967; Taubert 1956. 1959; Verougstraete and van Schoute 1997). The approach has been particularly popular in examining 15th Century Flemish paintings. The method is based on the fact that different elements and compounds vary in their reflectance of IR waves when illuminated with incandescent light, allowing areas of different material composition to be distinguished and some materials to be seen through. False-color infrared photography, which combines information on visible and near-infrared light, was used by Hirsch (1987) with incandescent lighting to reveal floor-tile paintings, and by Salzer (1987) with ultraviolet lighting causing material fluorescence to distinguish the pigment of rock art images from natural mineral stains and plant growth on sandstone cave walls.
In art-historical and archaeological IR applications such as these, a wide range of wavelengths–from near to mid-range infrared–are typically sensed in combination to produce a single image. In contrast are some approaches used in aerial and satellite remote sensing, where the infrared spectrum is broken into multiple bands of varying wavelength. Only certain bands relevant to the spectral response of a particular material may be monitored, as in mineral prospecting (e.g., Goetz 1976, 1984; Goetz et al. 1985; Hunt et al 1971 Nicolais 1974; Smith 1977), vegetational mapping (e.g., National Academy of Sciences 1970; Sadler 1987; Savastano et al.1984), or military surveillance. An alternative approach especially relevant to this project is “hyperspectral imaging” or “image spectrometry”. A very large number of narrow bands (e.g., 10 nm) covering a wide range of wavelengths (e.g., .4 – 2.5 microns) are sensed simultaneously, resulting in a digital image where each pixel documents a spectrum of wavelengths. Pixels can then be characterized for their spectra in order produce compositional maps of mineral or forest-canopy species distributions, which are most interpretable when reference spectra for minerals or plant species are known (e.g. Kruise 1990; Hook and Rast 1990; Johnson et al 1992). This approach was used by Bearman ( Bearman et al 1993; Bearman and Spiro 1996) to read faint lettering on darkened sections of the Dead Sea Scrolls. Bearman is one of this project’s team members.
Ultraviolet photography has been found in art history to be optimal for detecting discontinuities in painted surfaces. Ultraviolet light incident on a material may produce fluorescence or phosphorescence in the visible spectrum, and/or ultraviolet radiation, any of which may be sensed and recorded (Derbiere 1947; de Wild 1929; Eastman Kodak 1998; Radley and Grant 1954).
Literature Review of Digital Image Enhancement Methods. Computerized digital image enhancement methods involve analyzing and/or modifying the grey-scale values, or red, green, and blue-scale values, or other nonvisible spectral values of the pixels that comprise a digital image. Enhancement methods include several major classes of display and mathematical routines, which are designed primarily to improve the information content of a digital image. They can be used to: (1) increase image contrast, (2) sharpen boundaries within images, (3) determine the spatial scales at which image information is richest, (4) partition and remove high frequency noise or low frequency trends or disjunctures, and (5) partition overlaid images (Carr 1987; Castleman 1979; Gonzalez and Winz 1977). Image enhancement can be done in either an exploratory or deductive manner. Either the image pixel values themselves, their histogram, or their Fourier transform are operated upon. Among the most essential methods of image analysis are: band selection, interband calculations, contrast-stretch histogram modification, histogram equalization, spectral analysis, and mathematical filtering with high-pass, low-pass, band-pass, and gradient-sensitive operators.
Image enhancement methods have been used for about thirty years for remote sensing by satellite and airplane (see above), geophysical prospecting (Davis 1973; Holloway 1958; Robinson et al 1970; Zurflueh 1967), archaeometric prospecting (Carr 1977,1982; Linington 1969; Scollar 1969, 1970; Weymouth 1985), and/or intrasite archaeological spatial analysis (Carr 1987; Lang 1992). Applications to archaeological photography are not yet common. Haigh and Ipson (1989) used a combination of Fourier analysis, linear contrast stretch, and histogram equalization to compensate for fogging and uneven partial darkening of an aerial photo of a hillfort in Scotland. Bearman (1996) applied convolution, sharpening, and histogram adjustments in Adobe Photoshop and NIH Image to a series of narrow, near infrared bands recorded from the Dead Sea Scrolls, in order to read lines of text that were hidden by the fading of carbon ink and the darkening of the papyrus. Salzer (1987) and Valiga and Scherz (1987) used image enhancement methods to improve the resolution of false-color infrared and color photographs of rock art, respectively. Stewart (1991) did the same on underwater photographs of the U.S.S. Hamilton (above). Carr (1987) and Lang (1992) used many image enhance-ment methods to resolve patterns in intrasite artifact distributions likened to poor quality photographs.
Preliminary Digital Photographic and Enhancement Studies. In preparation for the NCPTT research project, many of the methods of image capture and enhancement reviewed above were explored for their capability in clarifying potential images on copper objects bearing a variety of material types. State-of-the-art digital cameras, computer image processing hardware and software, and printing systems were employed- -the same to be used in the proposed project (see Facilities and Equipment). Work was funded by Eastern National Parks and Monuments Assoc. and Arizona State University.
(1) Color slides were taken of both sides of all 320 extant copper plaques, headplates, and celts from Ohio. Color and textural differences over each item were enhanced by printing the slides with a Canon color copier. All potential images showing on the original items and the prints were sketched.
(2) A diverse sample of 105 item-sides of copper plaques, celts, and headplates was selected for study, based on step 1. The artifacts vary in the classes of apparent images they bear and span many of the kinds of materials and apparent artistic processes described above.
(3) Color (RGB) digital photographs were taken of the 105 item-sides using an ultra-high resolution portable (Leaf Lumina) digital camera with 3360 x 2253 pixels and incandescent illumination. Curved headplates were photographed with minimal distortion using an adaptation of “photomosaicing” techniques pioneered in aerial landscape mapping. Photomosaicing is a procedure for piecing together a flat layout photograph of a curved surface from multiple photographs taken of it from different vantage points. As applied here, the digital camera was held secure in one position and the curved headplate was rotated to several different photographing positions about its approximate center of curvature on a formed, Styrofoam support, keeping the lens-to- object distance constant. The photographs taken at different rotation positions overlapped in coverage. The multiple photographs were then spliced together in the computer using Adobe Photoshop’s scaling, rotating, skewing, and stretching routines. This approach was successful (Carr and Lydecker 1997).
(4) A large suite of image enhancement methods was tested on the 105 item-sides for their effectiveness in improving the contrast, boundary sharpness, and definition of potential compositions, and in revealing previously unnoticed figures of kinds known or thought to occur on other copper objects. The current version of Adobe Photoshop was used to make the enhancements.
One general strategy of enhancement was found most useful, and subsequently tested in the NCPTT-supported research. (a) Two copies of a given potential image were made on the CRT screen. (b) Image contrast of the two copies was optimized using two different routines: “contrast-stretch histogram modification” operating on the red, green, and blue bands, first together and then individually. (A third contrast-improving routine– histogram equalization–was seldom found effective.) (c) The optimized red, blue, and green bands of both enhanced images were assessed for which ones contained the greatest information about potential figures. Often, the red and blue bands proved most revealing, apparently because they minimized the noise of any greenish, natural corrosion products. (d) The most informative color bands and their inverses were multiplied by, divided by, added to, and subtracted from each other, in order to bring out suspected or unsuspected material types and images. (e) Each resulting calculated band had its contrast optimized using contrast-stretch histogram modification. (f) The bands were compared to each other in search for either quasi-stable patterns that repeated over several bands, or for figures that occurred uniquely in one band but that were known to resemble figures on other copper objects. These two criteria afforded a level of confidence in the reality of the images found. (g) Found images were ground-truthed for their visibility in the original copper objects as a final test of their reality. (h) High, low, and band-pass filtering were not found effective. This effectiveness of this routine was tested in the NCPTT research project with better information on the nature of the materials on the artifacts and how material type affects image enhancement.
This strategy outlined in steps a – g almost always led to the clarification of images seen directly by eye on the objects. It also allowed us to find images that were not at first seen visually, but that became recognizable once the naked eye’s attention was brought to them. Finally, on 22 of the sample items (ca. 19%), apparent “underpaintings”-were observed–layered sequences of paintings, corrosion, or patination. Different calculated bands revealed the same or similar human or animal figures, but significantly offset from each other, different in size, and or different in orientation. The possible “underpaintings” remain to be verified physically. The IR photography used in the NCPTT research helped resolve these possible painting sequences.
(5) A strategy was developed for separately displaying each of the multiple, individual design aspects (layers of information) found in a composition. This was necessary because the potential compositions, like much of Hopewellian art, often involve multiple conjoined, nested, and/or overlaid figures, with figure-ground reversal; these figures are hard to see and make sense of when displayed simultaneously. The display strategy involved: (a) laying acetate sheets on the enhanced image and making line tracings of each individual layer of information/figure on its own sheet; (b) raster- scanning each tracing into the computer; (c) autotracing each raster scan into a vector version, so as to produce a line drawing of consistent line width; (d) reconverting each tracing to a raster images and superimposing it on the enhanced image; and (e) printing a combination of the image enhancement and a tracing, one for each layer/tracing made.
(6) Near-infrared (.715 – 1.1 microns), midrange infrared (1.0 – 1.8 microns), thermal infrared (8 – 14 microns), and ultraviolet (.35 – .38 microns) cameras of military quality at Battelle Laboratories were used to photograph 6 sides of 6 items bearing the 11 potential pigments/binders described above, and certain organic materials. The work showed that only near and midrange infrared wavelengths are useful. These allowed the boundaries of artistic images to be sharpened, the revealing of some largely hidden images, and the mapping of sparse pigment distributions that were invisible to the naked eye. Near and midrange infrared photography are complementary in these regards relative to each other and visible light photography.
(7) Short and long-wavelength ultraviolet black lamps (.254 and .366 microns) were found ineffective in revealing imagery on 20 items with the 11 potential pigments and binders.
(8) Various hardware and software for printing enhanced color and infrared digital photographs were compared for the resolution, contrast, and texture they offer. The Canon 800 series color copier, with its good resolution (400 dpi) and an important edge enhancement routine, was found to offer the most information-laden images.
Chapters That Follow
The subsequent chapters of this final report summarize research directly supported by NCPTT. Chapter 2 identifies and maps the distribution of minerals found on the surface of a sample of Ohio Hopewellian copper artifacts, and begins to posit the kinds of formation processes (purposeful or otherwise) by which the materials came to reside on the artifacts. Chapter 3 evaluates theoretically and quantitatively whether the varieties of copper corrosion products found on individual headplates, breastplates, celts, earspools, and other copper items of the Ohio Hopewell were likely the result of fully natural, random, in situ corrosion or, instead, the product of some kind of intentional, cultural, artistic activity (e.g.., painting, patination). It also assesses whether the broken edges of some copper breastplates were relatively modern or ancient in age, in order to determine whether the artifacts may have been decommissioned by breaking them into culturally prescribed forms found elsewhere in Hopewell art. Chapter 4 establishes visual criteria for identifying kinds of organic materials that are found on Ohio Hopewellian copper artifacts, identifies and maps the distribution of those materials on a sample of such artifacts, and begins to posit the kinds of formation processes – purposeful or otherwise – by which the materials came to reside on the artifacts. Chapter 5 identifies the occurrence or lack of occurrence of textiles on Ohio Hopewellian copper artifacts, maps their distribution on such items, describes their various textile characteristics, and determines how textiles came to occur on the artifacts, intentionally or otherwise. Chapter 6 reports the replication of Hopewellian copper artworks using patination techniques available to Hopewellian peoples. The chapter verifies patination as a process by which Hopewellian copper artworks were commonly made, as concluded from the materials analyses reported in Chapter 2, 3, and 4. Chapter 7 reports how information from color and infrared digital photographs of the copper artifacts were made and evaluates them qualitatively for their effectiveness in revealing Hopewellian artistic compositions. Discussions consider photographic hardware and software, image capture for flat and curved objects, photographic enhancement, registration of color and infrared images, and the utility of particular spectral bands, band calculations, and hybrids of bands. Chapter 8 develops a digital photographic, quantitative model for identifying different kinds of surface materials found on Hopewellian copper artifacts from their spectral responses. The model clarifies which surface materials are more or less resolvable from each other photographically, and thus which aspects of artistic compositions contribute to their photographic clarity or obscurity. The model also reveals the particular spectral bands more and less effective in discriminating among surface materials and in revealing artistic compositions.
Hopewell and Related Eastern U.S. Archaeology
Brose, David S., James A. Brown, and David W. Penney
1985 Ancient Art of the American Woodland Indians. Harry Abrams, New York.
Brose, David S., and N’omi Greber
1979 Hopewell Archaeology: The Chillicothe Conference. Kent State University
Brown, James A.
1981 The Search for Rank in Prehistoric Burials. In The Archaeology of Death, ed. by
R. Chapman, I. Kinnes, and K. Randsborg, pp. 25-30. Cambridge University Press, Cambridge.
1982 Mound City and the Vacant Ceremonial Center. Unpublished paper presented at the Society for American Archaeology, annual meeting, Minneapolis.
Carr, Christopher. 1998.An Overview of some Essential World View Themes and Specific Beliefs Expressed in Ohio Hopewell Art and Burial Practices. Unpublished paper presented at the Midwestern Achaeological Conference, annual meetings, Muncie, IN, October.
1999. The Adena Tablets of Ohio, Kentucky, and West Virginia: Continuity and Change in the Cosmology of Woodland Native Americans. Unpublished paper presented at the Society for American Archaeology, annual meetings, Chicago, March.
Carr, Christopher, and Herbert Haas. 1996. Beta-Count and AMS Radiocarbon Dates of Woodland and Fort Ancient Period Occupations in Ohio, 1350 B.C. – A.D. 1650. West Virginia Archeologist48(1&2):19-33.
Carr, Christopher, and Jean-Christophe Komorowski. 1995. Identifying the Mineralogy of Rock Temper in Ceramics with X-Radiography. American Antiquity60(4):723-749.
Carr, Christopher, and Robert Maslowski. 1995. Cordage and Fabrics: Relating Form, Technology, and Social Process. In Style, Society, and Person, ed. by C. Carr and J. E. Neitzel, pp. 297-340. Plenum, New York.
Dancey, William S. 1991 A Middle Woodland Settlement in Central Ohio: A Preliminary Report on the Murphy Site (33LI212). Pennsylvania Archaeologist61(2):37-72.
Dancey, William S., and Paul J. Pacheco. 1997 A Community Model of Ohio Hopewell Settlement. In Ohio Hopewell Community Organization, ed. by W. S. Dancey and P. J. Pacheco, pp. 396-402. The Ohio Archaeological Council, Columbus.
Greber, N’omi. 1983 Recent Excavations at the Edwin Harness Mound. Mid-Continental Journal of Archaeology, Special Publication5. Kent State University Press, Kent, OH.
Greber, N’omi. 1979 Variations in Social Structure of Ohio Hopewell Peoples. Mid-Continental. Journal of Archaeology4(1):35-76.
Greber, N’omi B. and Katharine C. Ruhl
1989 The Hopewell Site. Westview Press, Boulder.
Griffin, James B. 1967 Eastern North American Archaeology: A Summary. Science156(3772):175-191.
Konigsberg, Lyle W. 1993 Demography and Mortuary Practice at Seip Mound One. Mid-Continental Journal of Archaeology18:123-148.
Moorehead, Warren K. 1922 The Hopewell Mound Group of Ohio. Field Museum of Natural History, Anthropological Series 6:73-184, plates 51-83. Otto, Martha Potter. 1975 A New Engraved Adena Tablet. Ohio Archaeologist25(2):31-36.
1992 A Prehistoric Menagerie: Ohio Hopewell Effigy Pipes. In Proceedings of the 1989 Smoking Pipe Conference: Selected Papers, ed. by C. F.Hayes, III, C. C. Bodner, and M. L. Sempowski, pp. 1-11. Rochester Museum and Science Center, Rochester.
Pacheco, Paul. 1988 Ohio Middle Woodland Settlement Variability in the Upper Licking River Drainage. Journal of the Steward Anthropological Society18:87-117.
Penney, David. 1980 The Adena Engraves Tablets: A Study of Art Prehistory. Mid-Continental Journal of Archaeology5(1):3-38.
1983 Imagery of the Middle Woodland Period: The Birth of a North American Iconographic Tradition. Unpublished paper presented at the Douglas Fraser Memorial Symposium on Primitive and Precolumbian Art, Columbia University, New York.
1985 Continuities of Imagery and Symbolism in the Art of the Woodlands. In Ancient Art of the American Woodland Indians, by D. S. Brose, J. A. Brown, and D. Penney. Harry Abrams, New York.
1989. Hopewell Art. Doctoral dissertation, Department of Art History and Archaeology, Columbia University. University Microfilms, Ann Arbor.
Prufer, Olaf, et al. 1965 The McGraw Site: A Study in Hopewellian Dynamics. Cleveland Museum of Natural History, Scientific Publications4(1).
Seeman, Mark F. 1979 The Hopewell Interaction Sphere: The Evidence for Interregional Trade and Structural Complexity. Indiana Historical Society, Prehistoric Research Series5(2):237-438.
1995. When Words Are Not Enough: Hopewellian Interregionalism and the Use of Material Symbols at the GE Mound. In Native American Interactions, ed. By M. Nassaney and K. Sassman, pp. 122-143. University of Tennessee Press, Knoxville.
Smith, Bruce. 1992. Rivers of Change. Smithsonian Institution Press, Washington, D.C.
Trevelyan, Amelia Margaret. 1987 Prehistoric Native American Copperwork from the Eastern United States.Unpublished doctoral dissertation, Department of Art History, University of California, Los Angeles. University Microfilms #3058, Ann Arbor, MI.
Webb, William S. and Raymond S. Baby. 1957. The Adena PeopleNo. 2. Ohio Historical Society, Columbus.
Trigger, Bruce G. (editor). 1978. Handbook of North American Indians, Northeast. Smithsonian Institution, Washington.
Wymer, Dee Anne. 1996 The Ohio Hopewell Econiche: Human-Land Interaction in the Coe Area. In A View from the Core: A Synthesis of Ohio Hopewell Archaeology, ed. by P. J. Pacheco, pp. 36-52. The Ohio Archaeological Council, Columbus.
1997 Paleoethnobotany in the Licking River Valley, Ohio: Implications for Understanding Ohio Hopewell. In OhioHopewell Community Organization, ed.by W. S. Dancey and P. Pacheco, pp. 153-171. Kent State University Press, Kent, OH.
Image Processing and Remote Sensing
American Society of Photogrammetry.1968. Manual of Color Aerial Photography. Falls Church, VA.
1983. Manual of Remote Sensing, 2nd edition. Falls Church, VA.
1984. SPOT Simulation Applications Handbook. Falls Church, VA.
Bearman, G. H., B. Zuckerman, K. Zuckerman, and J. Chiu. 1993. Multi-Spectral Imaging of Dead Sea Scrolls and Other Ancient Documents. Paper presented at the annual meeting of the Society of Biblical Literature, Washington D.C., November.
Bearman, Gregory H. and Sheila I. Spiro. 1996. Archaeological Applications of Advanced Imaging Techniques. Biblical Archaeologist59(1):56-57.
Carr, Christopher. 1977 A New Role and Analytical Design for the Use of Resistivity Surveying in Archaeology. Mid-Continental Journal of Archaeology2(2):161-193.
1982 Handbook on Soil Resistivity Surveying: Interpretation of Data from Earth from Earthen Archaeological Sites. Center for American Archaeology, Evanston, IL.
1987 Dissecting Intrasite Artifact Palimpsests Using Fourier Methods. In Method and Theory for Activity Area Research: An Ethnoarchaeological Approach, ed. by ‘S. Kent, pp. 236-291. Columbia University Press, New York.
Carr, Christopher, and Andrew D. W. Lydecker. 1997. Exploring the Possibility of Artwork on Ohio Hopewell Copper Artifacts (ca. 50 B.C. – A.D. 350) with High-Resolution Digital Photography, Image Enhancement, and Electron Microprobe Chemical Analysis. Unpublished report submitted to Eastern National Parks and Monuments Association, WWW.NPS.GOV\HOCU. 29 pp.
Castleman, Kenneth R. 1979. Digital Image Processing. Prentice-Hall, Englewood Cliffs, N.J.
Davis, John C. 1973. Statistics and Data Analysis in Geology. Wiley, New York.
Davis, R. P. Stephen, and Vincas P. Steponaitis. 1996. Scanning the Past: Applying Digital Photography to theNAGPRA Inventory Process. Unpublished paper presented at the annual meeting of the Society for American Archaeology, New Orleans, April
DeBoer, J. R. J. van Asperen. 1979. Infrared Reflectography: A Contribution to the Examination of Early European Paintings. Central Research Laboratory for Objects of Art and Science, Hobbemastraat 25, Amerstam.
Derbiere, M. 1947. Etude du comportement des pigments vis-a-vis de l’infrarouge photographique et de sechage. Peintures, Pigments, Vernis20:99-110.
Desneux, J. 1958. Underdrawings and Pentimenti in the Pictures of jan van Eyck. Art Bulletin40:13-21.
de Wild, A. M. 1929. The Scientific Examination of Pictures. G. Bell and Sons, London.
Dunkerton, Jill, Ashok Roy, and Alistair Smith. 1987. The Unmasking of Tura’s Allegorical Figure: A Painting and Its Concealed Image. National Gallery, Technical Bulletin11:5-35.
Eastman Kodak. 1998 Ultraviolet and Fluorescence Photography: Technique and Application. Eastman Kodak Company, Rochester, NY 14650.
Goetz, A. F. H. 1976. Remote Sensing Geology: Landsat and Beyond. Caltech/JPL Conference onImage Processing Technology, Data Sources, and Software for Commerical and Scientific Applications. Jet Propulsion Laboratory, SP 43-30, pp. 8-1 to 8-8.
1984 High Spectral Resolution Remote Sensing of the Land. Society of Photo-Optical Instrumentation Engineers, Proceedings475:56-68
Goetz, A. F. H. et al. 1985. Imaging Spectrometry for Earth Remote Sensing. Science228(4704):1147-1153.
Gonzalez, Rafael C., and Paul Winz. 1977. Digital Image Processing. Addison-Wesley, Reading, MA.
Haigh, J. G. B. and S. S. Ipson. 1989. Image Processing in Archaeological Remote Sensing. Computer Applications in Archaeology, p. 99.
Hirsch, Ethel S. 1987. Infrared Photography and Archaeology: Painted Floors at Gournia. Archaeology28:261-266
Holloway, J. Leith. 1958. Smoothing and Filtering of Time Series and Space Fields. Advances in Geophysics4:351-389.
Hook, S., and M. Rast. 1990. Mineralogical Mapping Using AVIRIS Shortwave Infrared Data Acquired over Cuprite, Nevada. Proceedings of the Second AVIRIS Workshop, JPL Publication90-5:199-207.
Hunt, G. R., J. W. Salisbury, and C. J. Lenhorf. 1971. Visible and Near-Infrared Spectra of Minerals and Rocks, III: Oxides and Hydroxides. Modern Geology2:195-205
Lang, Stephen Anthony. 1982. An Investigation of Image Processing Techniques at Pincevent Habitation No. 1, A Late Magdalenian Site in Northern France. Arizona State University, Anthropological Research Papers, 3.
Lilles, Thomas M., and Ralph W. Kiefer. 1987. Remote Sensing and Image Interpretation. John Wiley & Sons, New York.
Linnington, R. E. 1969. The Rome Computer System of Treating Archaeological Suvey Results: Second Part. Prospezioni Archeologiche4:9-58. Fondazione Lerici, Rome.
Marijnissen, R. H. 1967. Degredation, Conservation et Restauration de l’Oeuvre d’Art. Editions Arcade, Brussels
McKim-Smith, Gridley, Greta Andersen-Bergdoll, and Richard Newman. 1988. Examining Velaquez. Yale University Press, New Haven.
National Academy of Sciences. 1970. Remote Sensing With Special Reference to Agriculture and Forestry. Washington, D.C.
Nicolais, S. M. 1974. Mineral exploration with ERTS imagery: Third ERTS-1 Symposium, NASA SP-351(1):785-796.
Panofsky, E. 1958. Early Netherlandish Painting. Harvard University Press, Cambridge, MA. Pratt, William K. 1978 Digital Image Processing. Wiley, New York.
Radley, J. A., and J. Grant. 1954. Fluorescence Analysis in Ultra-violet Light. van Nostrand Company, Inc. New York.
Robinson, J. E., H. A. K. Charlesworth, and M. J. Ellis. 1969. Structural Analysis Using Spatial Filtering of Interior Plains of South-Central
Alberta. Bulleting of the American Association of Petroleum Geologists53:2341- 2367.
Roy, Ashok. 1988. The Technique of a ‘Tuchlein’ by Quinten Massys. National Gallery, Technical Bulletin 12:36-43. The National Gallery.
Sadler, S. A. 1987. Analysis of Effective Radiant Temperatures in a Pacific Northwest Forest Using Thermal Infrared Multispectral Scanner Data. Remote Sensing of Environment19(2):105-116.
Salzer, Robert J. 1987. Preliminary Report on the Gottschall Site 47Ia80. The Wisconsin Archaeologist. 68(4):277-287.
Savastano, K. J., K. H. Faller, and R. L. Iverson. 1984. Estimating Vegitation Coverage in St. Joseph Bay, Florida with an Airborne
Multispecral Scanner. Photogrammetric Engineering and Remote Sensing50(8):1159-1170.
Scollar, Irwin. 1969. Fourier Transform Methods for the Evaluation of Magnetic Maps. Prospezioni Archeologiche5:9-40.
1970. Some Techniques for the Evaluation of Archaeological Magnetometer Surveys. World Archaeology1(1):79-89.
Smith, W. L. (editor). 1977. Remote-Sensing Applications for Mineral Exploration. Dowden, Hutchinson, & Ross, Inc., Stroudsburg, PA.
Stewart, Kenneth. 1991. Visualization Strategies and Resources for Remote Sensing Exploration. The Jason Project.
Taubert, J. 1956. Zur Kunstwissenschaftlichen Auswertung von Naturwissenschaftlichen
Gemaldeuntersuchungen. Inaugural-Dissertation, Philipps-Universitat, Marburg.
1959 La Trinite du Musee de Louvain. Une Nouvelle Methode de Critique des Copies. Bull. Inst. Roy. Patr. Art2:20-33. Bruxelles
Valiga, James and James Scherz. 1987. Visual and Computer Assisted Analysis of Amerindian Rock Paintings. American Society for Photogrammetry and Remote Sensing, annual convention, Technical Papers 2.
Verougstraete, Helene, and Roger van Schoute. 1997. Les Petites Pietras du Groupe van der Weyden: Mecanismes d’une production en serie. Techne5:21-27.
Weymouth, John. 1985. Geophysical Methods of Archaeological Site Surveying. Advances in Archaeological Method and Theory8:101-156.
Zurflueh, E. G. 1967. Applications of Two Dimensional Linear Wavelength Filtering. Geophysics32:1015-1035.
Paleoethnobotany, Archaeological Textiles, and Mineralogy
Braun, E. Lucy. 1974. Deciduous Forests of Eastern North America. Free Press, New York.
1961. The Woody Plants of Ohio. The Ohio State University Press, Columbus.
Chen, Hsiou-lien. 1995. Microstructures of Mineralized Cellulosic Fibers. Unpublished doctoral dissertation, Department of Consumer and Textile Sciences, The Ohio State University, Columbus.
Core, H.A., W.A. Cote, and A.C. Day. 1979. Wood: Structure and Identification. Syracuse University Press, New York.
Emery, Irene. 1980. The Primary Structures of Fabrics. The Textile Museum, Washington, D.C.
Ford, Richard I. 1979. Paleoethnobotany in American Archaeology. In Advances in Archaeological Theory1:285-336. Academic Press, New York.
Gordon, Robert B. 1966. The Natural Vegetation of Ohio in Pioneer Days. Ohio Biological Survey 3(2):1-113.
Jakes, K.A., and J. H. Howard III. 1986. Replacement of Protein and Cellulose Fibers by Copper Minerals and the Formation of Textile Pseudomorphs. In Conservation and Characterization of Historical Paper and Textile Materials, e. by. H. Zeronian and H. Needles. Advances in Chemistry Series No. 212, American Chemical Societ
Jakes, Kathryn A., and Lucy R. Sibley. 1983. Survival of Cellulosic Fibers in Archaeological Contexts. Science and Archaeology25:31-38.
1984 An Examination of the Phenomenon of Textile Fabric Pseudomorphism. In Archaeological Chemistry, III, ed. by Joseph B. Lambert, pp. 403-424. American Chemical Society, Washington, D.C.
Jakes, K. A., L. R. Sibley, and R. W. Yerkes. 1994. A Comparative Collection for the Sudy of Fibers Used in Prehistoric Textiles from Eastern North America. Journal of Archaeological Science21:641-650
Martin, Alexander C. and William D. Barkley. 1973. Seed Identification Manual. University of California Press, Berkeley.
Montgomery, Frederick H. 1977. Seeds and Fruits of Plants of Eastern Canada and Northeastern United States. University of Toronto Press, Toronto.
Panshin, A.J., and Carl de Zeeuw. 1980. Textbook of Wood Technology.McGraw-Hill, New York.
Pearsall, Deborah M. 1989. Paleoethnobotany: A Handbook of Procedures. Academic Press, San Diego.
Roberts, W.L., J. Campbell, and G. R. Rapp. 1990. Encyclopedia of Minerals, 2nded. Van Nostrand, Reinhold, New York.
Sibley, L. R., and K.A. Jakes. 1984. Survival of Protein Fibers in Archaeological Contexts. Science and Archaeology26:17-27.
Sibley, L. R., K. A. Jakes, andJ. E. Katon. 1992. Etowah Feather Remains from Burial 57: Identification and Context. Clothing and Textiles Research Journal10(3):21-28.
Song, Cheusoon Ahn. 1991. Variations in Fiber Morphology on Prehistoric Textiles fromthe Seip Group of Mounds: A Model of Explanation. Unpublished doctoral dissertation, Department of Consumer and Textile Sciences, The Ohio State University, Columbus.
Srinivasan, R., and K.A. Jakes. 1997. Optical and Scanning Elecron Microscopic Study of the Effects of Charring on Indian Hemp (Apocynum cannibinum L.) fibers. Journal of Archaeological Science24:517-527.
United States Department of Agriculture, Forest Service. 1974. Seeds and Woody Plants in the United States. Agricultural Handbook450. United States Government Printing Office, Washington, D.C.
Weishaupt, Clara G. 1971. Vascular Plants of Ohio. Kendall/Hunt Publishing Co., Iowa.
Wymer, Dee Anne. 1990. Archaeobotany. In Childers and Woods: Two Late Woodland Sites in the Upper Ohio Valley, Mason County, West Virginia, edited by Michael J. Shott, pp. 402-535. University of Kentucky, CulturalResource Assessment Archaeological Report 200.