John W. Rick

Dates as Data: An Examination of the Peruvian Preceramic Radiocarbon Record

Radiocarbon dates can provide an effective overview of regional trends in non-complex societies when treated in a quantitative manner. In spite of intervening biases, numbers of radiocarbon dates should reflect the patterns of occupation across time. Using the date record ofpreceramic Peru, I illustrate very different radiocarbon trends for highland and coastal zones. These suggest exponential growth, equilibrium, and altitude shift for the occupations of coastal, puna, and highland valley regions. Biases caused by variation in temporal and geographic investigation, and the effects of sea-level rise are considered, but I argue that general occupational patterns overshadow distortions of the date record.

Downslope Movement and Archaeological Intra-Site Spatial Analysis

Erosion can produce heterogeneous distributions of cultural materials of differing densities, weights, and shapes within an archaeological site. A large, provenienced surface collection from a preceramic site in highland Pertu is examined for evidence of downslope movement as an explanation for observed heterogeneity in artifact distribution. Statistical methods of spatial analysis are used to define the extent of movements of surface materials in this site. For this particular area of Perti, critical angles for downslope movement will limit the site areas in which analysis of horizontal distributions can be expected to produce culturally significant information.

Conveying shape and features with image-based relighting

Hand-crafted illustrations are often more effective than photographs for conveying the shape and important features of an object, but they require expertise and time to produce. We describe an image compositing system and user interface that allow an artist to quickly and easily create technical illustrations from a set of photographs of an object taken from the same point of view under variable lighting conditions. Our system uses a novel compositing process in which images are combined using spatially-varying light mattes, enabling the final lighting in each area of the composite to be manipulated independently. We describe an interface that provides for the painting of local lighting effects (e.g. shadows, highlights, and tangential lighting to reveal texture) directly onto the composite. We survey some of the techniques used in illustration and lighting design to convey the shape and features of objects and describe how our system can be used to apply these techniques.

Projectile Points, Style, and Social Process in the Preceramic of Central Peru

This paper argues that, to move forward in research on stone tool style, we must supplement theoretical discussion with examination of large data sets for stylistic patterning. Using a large projectile point collection excavated from cave sites in the high altitude region of central Peru, I demonstrate the presence of robust patterning at a number of levels of stylistic resolution. I use hierarchy of stylistic subdivisions within the projectile point class to evaluate key variables at a number of stylistic scales, including measures of diversity and continuity. The analysis produces evidence of stylistic foci and transitions between them that reflect social process: the evolving social conditions which affect the material output of identity. I argue that there is evidence of complex residential and interactional relationships across time and among the occupants of these Andean sites.

On the Acoustics of the Underground Galleries of Ancient Chavín de Huántar, Peru

Chavin de Huantar is a monumental World Heritage archaeological site in the Peruvian highlands predating Inca society by over 2000 years. The importance of site acoustics is suggested by distinctive architectural features, notably an extensive network of underground galleries used in part for ritual purposes. The labyrinthine galleries are arranged in a series of small rectangular alcoves off narrow corridors. Here we focus on measuring and modeling the acoustics at Chavin to understand the implications of auditory experiences within the galleries as related to the sites role in developing religious authority. Acoustic measurements and models of a site can be used to archive site acoustics, estimate the acoustics of inaccessible or alternative site architectures, and reconstruct original site acoustics; they may also be used to corroborate aspects of rituals suggested by other archaeological data. Preliminary acoustic measurements at Chavin show a short reverberation time, dense and energetic early refle...

Characteristics and speculations on the uses of Strombus trumpets found at the ancient Peruvian center Chavín de Huántar

A cache of 20 Strombus shell trumpets was excavated in 2001 from an underground gallery at Chavin de Huantar, the type site of the Peruvian Early Horizon period (ca. 1200 to 400 B.C.). Strombus shell usage stretches from antiquity to present day Peru, with the trumpet function showing remarkable continuity. Soon after their discovery, a dozen of the ancient shells were played to an enthusiastic audience at Lima’s National Museum of Archaeology, Anthropology and History. Evidence suggests that Strombus trumpets are, and were, used as ritual instruments for the legitimization of political and religious power. Those uses may have developed from earlier practical uses for ritual and communication. This paper describes measured acoustical properties of a Strombus horn. Strombus blasts are rich in overtones. Source strengths as high as 111 dBA @ 1 M were observed. These high source levels support speculation that shell trumpets could have been used for signaling over great distances. The trumpets can produce strong combination tones, which, accompanied by likely ingestion of local hallucinogenic substances, the use of reflected light, and other sound manipulation, suggests that early leaders in Chavin were using a range of methods to help establish early religious and political authority.

A modular computational acoustic model of ancient Chavín de Huántar, Perú.

Inspired by on‐site observations and measurements, a computational acoustic model of the interior architecture of the 3000‐year‐old ceremonial center at Chavin de Huantar, Peru is presented. The model addresses the foundational study by Lumbreras et al. (1976) which posited an acoustic system integral to Chavin architecture involving “a network of resonance rooms connected by sound transmission tubes.” We propose a translation of the topology of Chavin gallery forms to a modular computational acoustic model based on bi‐directional digital waveguides, representing the corridors and ducts, connected through reverberant scattering junctions, representing the small rooms. This approach combines known architectural dimensional and material data with representative measured acoustic data, thus economizing the collection of impulse response measurements required to accurately simulate site acoustics. Applications include virtual acoustic reconstruction of inaccessible or demolished site structures, and auralizations of hypothesized architectural forms, allowing any desired sound sample to be “played back” in the modeled acoustic context.

Acoustic analysis of the Chavín pututus (Strombus galeatus marine shell trumpets).

In 2001, a group of twenty Strombus galeatus marine shell trumpets were excavated at the 3000‐year‐old ceremonial center at Chavin de Huantar, Peru, marking the first documented contextual discovery of intact sound producing instruments at this Formative Period site in the Andean highlands. These playable shells are decorated, use‐polished, and additionally modified with a V‐shaped cut to the outer apical lip. We present an acoustic analysis of the measured response of each instrument, to a variety of excitations, at microphones placed in the mouthpiece, bore, bell, and surrounding near‐field. From these measurements we characterize each instrument’s sounding frequency, radiation pattern, and impedance, and estimate its bore area function. Knowledge of the specific acoustic capabilities of these pututus allows us to understand and test their potential as sound sources in the ancient Chav\’{i}n context, whose architectural acoustics are simultaneously studied by our research group.

Early Highland Andean Archaic

relative time period: Follows the Late Andean Hunting-Collecting tradition and is followed by the Late highland Andean Archaic tradition.

Punas, Pundits, and Prehistory: Comment on Wheeler's Review of “Prehistoric Hunters of the High Andes”

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