OPTICAL DATING OF GRANITIC STONE SURFACES*

A novel luminescence methodology for dating surfaces of granitoid rocks is presented, with encouraging results for archaeological stone structures. It is based on the zeroing of the latent signal of optically stimulated luminescence (OSL) in feldspar and quartz grains of the stone surface during exposure to daylight. When after bleaching the surface is shielded from light, the OSL signal builds up again, such that its intensity provides an age for the event of the last exposure to light. This event could be the construction or the destruction of stone structures or, for example, sedimentary deposition of granitic boulders, such as in fan deposits. The experimental approach utilizes a high spatial resolution detection technique (HR‐OSL) for OSL of minerals that are left in their original petrological context; that is, without any mineral separation. With this approach, steep gradients in microdosimetry at the surface and at grain boundaries become important and are discussed in detail. The new dating technique is successfully applied to a stone wall of the medieval castle of Lindenfels in southwestern Germany and the pre‐Columbian Nasca lines (geoglyphs) around Palpa in southern Peru.     

Tracing the clay source of Nasca polychrome pottery: results from a preliminary raw material survey

This paper describes the results of the first season of a survey in which clays suitable for the production of Nasca polychrome pottery were collected in an effort to (1) determine the geological variability of clay sources in the Nasca region and (2) match clays compositionally to paste groups from previous provenance analyses. Clays were collected, processed, fired, and analyzed using neutron activation. The results demonstrate that clays in the region were compositionally heterogeneous, and that the clay source for the majority of Nasca polychrome pottery sampled thus far can be traced to lower valleys in the region near the ancient ceremonial center Cahuachi. The results have implications for understanding the nature of polychrome pottery production in the Nasca region, and suggest centralized production near the ceremonial center of the majority of painted ceramics consumed in the Southern Nasca Region.     

A compositional perspective on the origins of the “Nasca cult” at Cahuachi

We provide a compositional perspective on the origins of the Cahuachi cult in Nasca, south coast of Peru. Instrumental Neutron Activation Analysis of ceramics from the Formative site of La Puntilla demonstrate that a small group of pottery known as Nasca 1 blackwares are compositionally consistent with Early Nasca polychromes originating at Cahuachi. These data suggest that the patterns of pilgrimage and group ceremonies exhibited at Cahuachi during Early Nasca began at least in the proto-Nasca phase of Nasca 1 during the Formative. We use these data to further document the Paracas to Nasca transition, a complex and dynamic period in south coastal prehistory.     

Obsidian hydration dating on the South Coast of Peru

We compare over 230 obsidian hydration readings from 30 individual site components from the Southern Nasca Region (SNR) with independent age estimates based on radiocarbon dates and temporally diagnostic artifacts. Although there are problems with small sample sizes, and readings must be adjusted for elevation, a very strong relationship accounting for nearly 90% of the total variation in the data set is found. This suggests that obsidian hydration dating (OHD) works in the SNR and is a viable means of independently estimating age. Residual values from our regression suggest that hydration age estimates are usually within 15% of the radiocarbon estimates. Finally, we present an equation other scholars can use to estimate age for Quispisisa obsidian in the SNR.     

The geographic origins of Nasca trophy heads using strontium,oxygen, and carbon isotope data

Scholars continue to debate the identity of individuals curated as trophy heads in the Nazca Drainage of southern Peru (c. 1–800 AD). What was the role of trophy heads in Nasca society? Were they victims of warfare or venerated ancestors? Strontium, oxygen, and carbon isotope data from archaeological human tooth enamel from Nasca trophy heads from Aja, Cahuachi, Cantayo, Majoro Chico and Paredones, and from individuals buried in Nasca cemeteries at Cahuachi, Cantayo, and Majoro Chico elucidate the geographic origins and paleodiet of trophy heads in the Nazca Drainage. The ⁸⁷Sr/⁸⁶Sr and δ¹⁸O_c(V-PDB) data from both the trophy heads and the Nazca Drainage burials are all quite variable, and do not support the hypothesis that the Nasca trophy heads were obtained from a geographically-distinct population. Similarly, the δ¹³C_c(V-PDB) data demonstrates that the individuals included in this study consumed similar diets. These data suggest that the Nasca trophy heads likely derive from the local Nasca population. Rather than obtain heads from enemy warriors through geographic expansion or warfare as seen in other parts of the world, this complex social practice existed within the Nasca polity throughout space and time.     

A comprehensive numerical chronology for the pre-Columbian cultures of the Palpa valleys,south coast of Peru

Before the arrival of the Spaniards in Peru in 1532, many different societies flourished in the coastal desert of southern Peru. Of these, one of the best known is the Nasca culture (living in the area between about 260 cal BC and 640 cal BC.), which created the famous geoglyphs on the desert floor. In this paper we present a numerical chronology for the cultural development in the valleys of Palpa, in the northern part of the Nazca region, which spans the time from the Archaic Period (starting there around 3760 cal BC) to the Late Intermediate Period (terminating with the arrival of the Spaniards in 1532 AD). The chronology is based on more than 150 ¹⁴C samples collected by our project from well-documented archaeological excavations of 17 different sites in and around Palpa. Thanks to the advanced AMS-¹⁴C dating technique, demanding only few milligrams of organic material, we could focus on samples of plants, like beans, corn, or reed, representing single years of growth or use, and also on delicate materials like straw from clay bricks (adobe) and textiles. All single ¹⁴C dates were combined to cultural phases using a Bayesian statistical model, implementing the a priori information of the archaeological contexts, and adopting the relative ceramic chronologies available for this area.     

Iron isotope analysis of red and black pigments on pottery in Nasca,Peru

The Nasca culture of the south coast of Peru developed during the first millennium ad and is known internationally for its elaborately decorated polychrome pots. Despite decades of iconographic analysis, little is known about the more technological aspects of Nasca pigment production and application. We present results from a pilot study on iron isotopes as a potential line of inquiry into the differences between red and black pigments in Nasca pigments. As well, we conduct a small firing experiment to examine potential changes in isotope composition. Our analyses show three significant results. First, firing does not change the isotopic ratios of Fe in pigments. Second, red and black pigments show differences in their iron isotope composition, which relate to differences in the minerals used to make the different colors. Third, naturally available hematite samples show greater isotopic variation than pigment samples, suggesting that people selected a limited range of iron oxides to produce pigments.     

Integrating radar and laser-based remote sensing techniques for monitoring structural deformation of archaeological monuments

Ground-Based Synthetic Aperture Radar Interferometry (GBInSAR) and Terrestrial Laser Scanning (TLS) were purposely integrated to obtain 3D interferometric radar point clouds to facilitate the spatial interpretation of displacements affecting archaeological monuments. The paper describes the procedure to implement this integrated approach in the real-world situations of surveillance of archaeological and built heritage. Targeted tests were carried out on the case study of the Domus Tiberiana sited along the northern side of the Palatino Hill in the central archaeological area of Rome, Italy, and displacements of the monument were monitored over almost one year of acquisition. The GBInSAR – TLS integration provided updated information about the condition of the archaeological structures in relation to their history of instability mechanisms, and did not highlighted a general worsening for the stability of the entire monument. Point-wise and prompt detection of displacement anomalies and/or sudden changes in displacement trends proved the suitability of the method to support early warning procedures, also to evaluate effects on the masonry due to human activities.     

Identifying foreigners versus locals in a burial population from Nasca, Peru: an investigation using strontium isotope analysis

During the several thousand years of human occupation in the Nasca drainage on the south coast of Peru, population movement into and out of the region impacted the formation and organization of society, as well as contributed to major cultural transformations. This study identifies foreign versus local individuals through the investigation of burial practices and strontium isotope analysis of human remains from the sites of La Tiza and Pajonal Alto dating from the Early Intermediate Period through the Late Intermediate Period (A.D. 1–1476). Of the ten samples analyzed, two individuals dating to the Middle Horizon were identified as foreigners. One of these individuals was buried in a new elite tomb type providing additional evidence that the Wari state incorporated Nasca into its realm. Two headless individuals, one dating to Middle Nasca with clear evidence of decapitation, and another dating to the Late Intermediate Period who was likely decapitated, were both locals. This suggests the practice of decapitation took place among local groups, and that the practice of decapitation and the use of heads as ritual items or trophies may have continued later in time than previously thought.     

Diversity of Pre-colonial Earthworks in the Brazilian State of Acre,Southwestern Amazonia

Amazonian earthworks, which are an important testimony to ancient anthropogenic landscape modifications, have a significant variety of structures and sizes, and are found in different geographical and ecological locations that indicate separate time periods, distinct cultural affiliations, and diverse purposes. We introduce data from diverse archaeological earthwork sites, geoglyphs, mound sites, and walled enclosures situated in the interfluves of the Purus River in the Brazilian state of Acre and propose a type definition for these sites. The abundant anthropogenic landscape features and their associated material culture indicate considerable human-induced environmental alterations and diverse earthworking traditions that are characteristic of the region of eastern Acre from at least ca. 2000 b.p. onwards.     

Ceramic production in ancient Nasca: provenance analysis of pottery from the Early Nasca and Tiza cultures through INAA

We report the results of an instrumental neutron activation analysis (INAA) undertaken on a regional sample of pottery from the Southern Nasca Region. The samples included specimens primarily from the Early Nasca (ca. A.D. 1–450) and Tiza (ca. A.D. 1000–1476) cultures from a total of 16 different prehispanic sites. The results of the analysis demonstrate centralized production of Early Nasca polychromes and decentralized production of pottery from the Tiza culture. The results of this analysis confirm previous conclusions about the organization of these two indigenous cultures of the south coast of Peru and support the hypothesis of an excess production of polychromes at the ceremonial center Cahuachi for Early Nasca, and multiple centers of production for the Tiza culture.     

Wari’s imperial influence on local Nasca diet: The stable isotope evidence

The highland Wari Empire established a presence within the Nasca region of south coastal Peru during the Middle Horizon period. To clarify the nature of this interaction, we analyzed stable carbon and nitrogen isotope ratios of human bone collagen from individuals living in the Southern Nasca Region (SNR) before (1–750 AD) and during (750–1000 AD) imperial influence. The stable isotope data do not indicate that the Wari Empire transformed maize agricultural labor in the Las Trancas Valley of the SNR. In fact, during both time periods, Nasca people had access to a wide range of food items.     

Pilgrimage as costly signal: Religiously motivated cooperation in Chaco and Nasca

Religiously motivated cooperation in the form of pilgrimage is a neglected element in discussions of the dynamics of cooperative behavior among humans. In this paper, we invoke costly signaling theory to propose how pilgrimage centers emerge in some contexts. On one hand, as has been suggested by other scholars, monumental centers are costly signals of the authority and influence of competing centers’ leadership, which can include the leaders’ influence over supernatural forces. We argue that equally important is the pilgrimage itself, which serves as a costly signal of the pilgrims’ commitment to the religious system and the beliefs and values associated with it; this in turn facilitates cooperation and other prosocial behaviors among pilgrims who otherwise might be strangers. To explore the utility of this approach to pilgrimage, we compare Chaco Canyon in the US Southwest and Cahuachi in the Nasca region of Peru, two prestate sociocultural settings in which pilgrimage was an important component in maintaining cooperation, group cohesion, and identity. While specific patterns are distinct in each society, we argue that pilgrimage had a significant impact in the development of both prosocial behavior and religious leadership in Chaco and Nasca.     

A pilot compositional analysis of Nasca ceramics from the Kroeber collection

In this paper we report on Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) of a sample of ceramics from Nasca, Peru collected by Alfred Kroeber in the 1920’s and curated at the Field Museum of Natural History in Chicago. The analysis was conducted for two principal reasons: (1) to test the efficacy of LA-ICP-MS when compared to INAA; and (2) to evaluate samples that post-date Early Nasca (where focus has primarily been placed). We show here that LA-ICP-MS is a viable alternative to INAA, present some of the compositional variability in the Kroeber samples, and propose some explanations for this variability.     

Refining oxygen isotope analysis in the Nasca region of Peru: An investigation of water sources and archaeological samples

The development of complex societies, irrigation agriculture and sociopolitical transitions are of interest to researchers working in the Nasca region on the south coast of Peru. Occupied for thousands of years, many questions regarding the circumstances of these changes in the area are being investigated. Oxygen isotope analysis provides a method for exploring residential mobility of past peoples during these transitions. This study presents new δ¹⁸O data from water sources that would have been used by the ancient inhabitants, providing important information regarding the oxygen isotope variability in the region and the necessary baseline data for migration studies in this region. Our results suggest that the isotopic composition of water sources in the Nasca region is not highly variable. In addition, archaeological human tooth enamel samples from the sites of La Tiza and Pajonal Alto are analysed. The δ¹⁸O_c results of the human enamel samples confirm the local nature of the burial population, as suggested by previous strontium isotope analysis (⁸⁷Sr/⁸⁶Sr). Copyright © 2010 John Wiley & Sons, Ltd. This article was published online on 13 January 2010. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected 15 January 2010.     

Regional integration and the built environment in middle-range societies: Paracas and early Nasca houses and communities

We use the built environment of residential sites (house form and community layout) to investigate the effects of increasing regional integration at the level of the community in middle-range societies. We consider spatial data on house form, arrangement of residences within settlements, site location, and organization of non-residential spaces to reveal specific social phenomena linked with pan-regional political organization and ethnic identity formation, and evaluate how macro-scale processes affect micro-scale phenomena. Specifically, we argue that architecture reflects different community patterns of ritual, integration, and inequality. As a case study, we employ a diachronic perspective for two periods in Peruvian south coastal prehistory to assess the magnitude of changes implied by the genesis of Nasca society out of the preceding Paracas. Survey and excavation data from residential sites in the southern Nasca region indicate that important modifications in local community organization accompanied the regional, wide-ranging effects of Nasca society and its innovative form of regional integration. Comparison of the residential built environment from both periods suggests important changes in ritual and patterns of status acquisition and maintenance. In addition, house form indicates that a greater level of household autonomy accompanied increasing regional integration and a decrease in conflict.     

Exploring Geographic Origins at Cahuachi using Stable Isotopic Analysis of Archaeological Human Tissues and Modern Environmental Waters

In this study, we used oxygen‐ and hydrogen‐isotope data from human bone (δ¹⁸O) and modern environmental water samples (δ¹⁸O and δD) to investigate geographic origins of individuals buried at Cahuachi, a ceremonial centre in the Nasca region of Peru (c.AD1‐1000). Our objective was to characterise the natural variation in water stable isotopic composition in the Rio Grande de Nasca drainage, and then to use these data to better infer place of origin for 30 adults interred at Cahuachi. Using the δ¹⁸O and δD values of 63 modern environmental water samples, it was possible to differentiate among the northern and southern river middle valleys, and to infer the isotopic composition of drinking water at higher elevations. Over half of the individuals included in this study had drinking water oxygen‐isotope compositions consistent with places of origin away from Cahuachi during the last 10 to 25 years of life, perhaps in the northern river middle valleys or in the upper valleys/sierra. The environmental water stable isotopic baseline developed in this study enabled a better understanding of the natural variation of waters in the Rio Grande de Nasca drainage. As a result, it was possible to assess the geographic range of place of origin for these individuals with greater certainty. Taken together, these data support the idea of Cahuachi as a place of both local and regional significance, with individuals from distant parts of the Rio Grande de Nasca drainage travelling to and/or transporting the dead to the site for death or burial. Copyright © 2011 John Wiley & Sons, Ltd.     

Geochemical analysis of Late Classic and Post Classic Maya marketplace activities at the Plazas of Cobá, Mexico

Abstract

Lines of evidence for ancient exchange plazas may include trade routes and trade artifacts, urban open space near public structures, and rock alignments denoting market stalls, but regular patterns in soil chemical concentrations also point to marketplace use. We applied geochemical and geospatial analysis of the floors of the main Plaza of Group B and Plazas A, H, and J of Group D at Cobá, Mexico, to discover the chemical residues of phosphorus (P) and metals associated with the exchange of foodstuffs and mineral workshop items that may have been marketed there. The patterns of chemical residues in the floor of the Group B Plaza suggest ritual activities while the linear, parallel patterns of elevated Mehlich phosphorus and chelate extractable zinc concentrations in Plaza A support the hypothesis of market exchange at that location. Plaza H is associated with several Postclassic buildings, including the Pinturas Structure D-33. During the Postclassic period, Cobá had lost much of its population, though chemical residues from Plaza H are congruent with marketing. We argue that Plazas A and H were not permanent marketplaces but rather multi-purpose locations that also hosted large ceremonies.     

A NEW THERMOLUMINESCENCE DATING TECHNIQUE FOR HEATED FLINT*

A new thermoluminescence (TL) technique for determining the age of heated flint artefacts from archaeological sites is presented. It is a variant of the SAR protocol, which is usually used for OSL dating of sediment, but it is not based on a presumed model for fitting the dose–response curve. Dose recovery tests as well as comparisons with standard protocols show the accuracy of the new technique. It is found that the sensitivity of the thermoluminescence (TL) signal of flint in the orange–red waveband does not show severe changes due to the heating process while measuring the TL. This allows the application of a short SAR procedure, which requires only two dose points. The technique does not require as much instrument time as other SAR techniques, and thus is advantageous for dating very old samples. The major advantage of this new technique is the small amount of sample material required, which allows the dating of samples that are too small for standard TL dating techniques.