The Great Maya Droughts in Cultural Context: Case Studies in Resilience and Vulnerability

11: Oxygen Isotopes from Maya Archaeological Deer Remains

231 DOI: 10.5876_9781607322801.c011 11 Oxygen Isotopes from Maya Archaeological Deer Remains Experiments in Tracing Droughts Using Bones Antoine Repussard, Henry P. Schwarcz, Kitty F. Emery, and Erin Kennedy Thornton An increasing number of studies support the concordance between dry episodes in the Circum-Caribbean Basin and the political disruption of Maya society at the end of the Terminal Classic, during the period often called the “Classic Collapse” (e.g., Haug et al. 2003; Hodell, Brenner, and Curtis 2007; Neff et al. 2006). However, the exact sequence of events and their impacts on the Maya people are still largely debated (see Iannone [Chapter 1],Aimers and Iannone [Chapter 2], Iannone, Yaeger, and Hodell [Chapter 3], this volume). The aim of this chapter is not to discuss these issues, but rather to examine the potential of using archaeological bone from white-tailed deer (Odocoileus virginianus) as an additional climatic proxy to track droughts in the Maya area. The archaeological remains are especially promising for this purpose because (1) they are relatively abundant in the Maya archaeological record; (2) they are associated with cultural remains,allowing them to be easily and accurately dated; and, most important, (3) they are considered as a very local recorder of past meteorological conditions. maTeRial The studied material consists of a total of eightythree bones of white-tailed deer (Odocoileus virginianus sp.) that were excavated from the archaeological sites of Piedras Negras (PN) by the Piedras Negras Archaeological Project directed by Stephen Houston and Hector Escobedo (71 bones), and Motul de San Jose (MSJ) by the Motul de San Jose Regional Archaeo-Ecological Project directed by Antonia Foias and Kitty Emery (12 bones). Both sites are located in 232 REPUSSARD, SCHWARCZ, EMERY, AND THORNTON Figure 11.1. Topographical map of the Maya region, showing the southern cordillera of the Sierra Madre de Chiapas (corresponding to the Maya highlands), the relatively flat lowlands in the northern part of the peninsula, and the lowaltitude Maya Mountains of southern Belize. The location of the studied sites, the major modern city of Flores, as well as the direction of the prevailing easterly winds, are shown. Background: SRTM shaded relief map of Central America (Courtesy NASA/JPL-Caltech). the Departamento del Peten, Guatemala; Piedras Negras along the shores of the Usumacinta River in western Peten; and Motul de San Jose a few kilometers from the Peten Itza Lake in Central Peten (Figure 11.1). Bones were identified to taxon, element, side, and age by Thornton and Emery (project zooarchaeologists for both the Piedras Negras and Motul de San Jose projects) using the comparative collections of the Florida Museum of Natural History (Environmental Archaeology Program). Only samples from separate adult individuals were selected by Emery and Thornton for this study. This determination was based on contextual and chronological separation between specimens or overlapping unique elements (e.g., two adult right deer femurs) within the same context. Context information was derived from published archaeological reports from the archaeological sites with assistance from archaeological project personnel. All bones are from assemblages well dated by stratigraphic and ceramic analysis by archaeologists associated with the two projects, and range from Preclassic (Piedras Negras) to Postclassic periods (Motul de San Jose and Piedras Negras; Table 11.1). OXYGEN ISOTOPES FROM MAYA ARCHAEOLOGICAL DEER REMAINS 233 backgRound Bioapatite, the mineral fraction of bone and teeth, has been described as a distinctive type of hydroxylapatite (Ca10 (PO4 )6 (OH)2 ), in which phosphate groups (PO4 3- ) are frequently (~7%) substituted by carbonate groups (CO3 2- ; Table 11.1 Origin, age, type, and number of bones analyzed in this study. Cultural phase Years (AD) ~Major period Number of bones Bone types Motul de San Jose Late Classic 600–800 6 Femur Terminal Classic 800–1000 5 Coxa, humerus, rib, tibia Early Postclassic 1000–1250 1 Metatarsal All phases 12 Piedras Negras Abal/Pom 300 BC–350 2 Ilium, metatarsal Naba 350–560 Early Classic 4 Humerus, ilium, mandible Balche 560–620 Early Classic 12 Acetabulum, calcaneus, femur, mandible, scapula, tibia, vertebrae Yaxche 620–750 Late Classic 26 Astragalus, calcaneus, femur, Humerus, Ilium, ischium, mandible, phalanx, pubis, radius, scapula Chacalhaaz 750–850 Late Classic 24 Astragalus, femur, humerus, ilium, ischium, mandible, metacarpal, metapodial, metatarsus, phalanx, radius, scapula, tibia Kumche 850–900 Terminal Classic 3 Metatarsal, tibia All phases 71 234 REPUSSARD, SCHWARCZ, EMERY, AND THORNTON Wright and Schwarcz 1996). Analyses of bioapatite oxygen isotopic composition (δ18 O) can thus...