Strontium Isotopic Identification of an Early Classic Migrant to Punta De Chimino, Guatemala
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Figure 1. Location of Burial PC103 at Punta de Chimino and photograph of the burial during excavation. Maya Archaeology Reports Strontium Isotopic Identification of anEarly ClassicMigrant toPuntadeChimino,Guatemala Lori E.Wright Bruce R.Bachand n recent years, studies of ancient migration have been skeletons buried at a site. Strontium isotope ratios have now revolutionized by the application of stable isotopic been used to document prehistoric migration in a variety of techniques that permit the assessment of place of origin archaeological contexts around the world (Bentley et al. 2002; Ifor individual human skeletons. The ratio between two of Grupe et al. 1997; Knudson and Price 2007; Knudson et al. 2004; the stable isotopes of strontium, 87Sr and 86Sr, is an especially Knudson et al. 2005; Montgomery et al. 2003; Montgomery et al. useful measure because the 87Sr/86Sr values of human remains 2005; Price et al. 1998; Price et al. 1994). are determined by the geology of the region in which a person In Mesoamerica, the volcanic highlands of Mexico and lived. While 86Sr is not radiogenic, 87Sr is produced by the decay Guatemala have 87Sr/86Sr ratios near .7045, while the limestones of rubidium (Rb), which has an extremely long half-life. Hence of the Maya lowlands have much higher 87Sr/86Sr ratios, ranging volcanic rocks, which contain little Rb due to their origin in the from .7075 to .7090. The southeastern periphery of the Maya earth’s mantle, have low 87Sr/86Sr ratios. By contrast, crustal lowlands has intermediate values, around .7069 at Copan, while sedimentary rocks have higher 87Sr/86Sr, due to their greater very high ratios (.7127) are seen in the metamorphic Maya Rb content and age (Faure 1986). Strontium is taken into the Mountains (Hodell et al. 2004; Price et al. 2008; Price et al. 2000; body through food and water, and substitutes for calcium in Wright 2005a). Hodell et al. (2004) defined five strontium isotopic the mineral structure of tooth enamel and bone. Because tooth regions through survey of environmental 87Sr/86Sr ratios in the enamel forms during childhood and is not remodeled later in life, Maya area: the Northern Lowlands, the Southern Lowlands, the it retains through life a ratio of 87Sr to 86Sr which represents the Maya Mountains, the Metamorphic Province, and the Volcanic values of foods consumed during childhood. Hence it is possible Highlands and Pacific Coast. Although there is some variability to identify the skeletons of immigrants to an archaeological within each of these regions, most of the Southern Lowlands site by comparing their dental 87Sr/86Sr with that of other local (from Alta Verapaz north to Campeche) show values ranging ©29 2009 In Maya Archaeology 1, edited by Charles Golden, Stephen Houston, and Joel Skidmore, pp. 28-35. San Francisco: Precolumbia Mesoweb Press. [electronic facsimile: www.mesoweb.com/articles/Wright-Bachand-2009.pdf] from .7069 to .7084, a fairly narrow range. Environmental data gouged-incised design depicting four curl-nosed saurian are helpful in defining expectations for local signatures; however, creatures (Figure 3). The vessel’s fine gray paste and volcanic dietary factors may also influence 87Sr/86Sr ratios of human ash temper suggest a highland manufacture. Mending holes skeletons. Thus measurement of local human 87Sr/86Sr ratios is below the rim indicate that this vessel had been repaired at important to define local ranges (Wright 2005a). some time prior to deposition. Thermoluminescence dating of This note reports on the stable strontium analyses of nine the polychrome vessel yielded a date of 180 BC ± 520 (University burials excavated by the Aguateca Archaeological Project in of Washington, UW-1152), for which the Bayesian adjusted range the Petexbatun region of the Department of Peten, Guatemala. is AD 325-504. Two of these are from Punta de Chimino and include an Early The skeleton in Burial PC103 is that of an adult, probably Classic mortuary deposit believed to contain the remains of a less than 50 years of age at death, judging from the dentition. possible foreigner, Burial PC103 (Bachand 2006, 2008; Bachand Although the orbital margins and the mental area appear et al. 2006). The second, Burial PC106, is from a contemporary masculine, long bone dimensions are intermediate between termination deposit. The remaining seven skeletons sampled those of males and females from the Pasión region of Guatemala are from domestic burials at the site of Aguateca, located (Wright 2006). Pelvic remains are very fragmentary, thus sex 4.5 km from Punta de Chimino on the margins of Lake and age cannot be determined with confidence. The maxillary Petexbatun (Figure 2). No aspects of their mortuary contexts central incisors and the canines are filed to Romero’s (1986) type suggest a non-local origin. Using the Aguateca data, we test B4 and A4, respectively. The lateral incisors show marked wear, the hypothesis that the individual in Burial PC103 was not a antemortem fractures, and large caries that may be secondary to local Petexbatun child but instead migrated into the region the filing decoration. An AMS date of 1634 ± 53 BP (cal AD 250- at some point prior to his or her death and burial at Punta de 550, 2-sigma, University of Arizona, AA-66263) was obtained Chimino. from a cortical diaphyseal sample of the skeleton’s left femur. Burial PC103 was contained within a cylindrical stone- Bayesian analyses of the radiometric data place the individual’s lined crypt or cist that penetrated the east-west axis of the late death date between AD 400 and 450. Protoclassic basal platform of Mound 7, the main pyramid on Burial PC103’s grave style and body posture are rather Punta de Chimino’s acropolis (Figure 1). Although its lateral uncharacteristic for the Pasión region (Wright 2006) and for dimensions were not determined, the platform itself contained the Early Classic Maya at large (Welsh 1988). Indeed, across several burials and extended eastward, away from the pyramid, the Southern Maya Lowlands the deceased were generally laid somewhat resembling contemporaneous adosada platforms at out in an extended and supine position or placed on one side Kaminaljuyu and Teotihuacan (Bachand 2006:183). The cist was in a flexed position in Early Classic times. Heads were usually 50 cm in diameter by 60 cm deep, ringed with limestone blocks positioned north, south, or east and covered with a single bowl, from top to bottom, and covered by several limestone slabs. often with a “kill hole” in the bottom. Seated burials occur at a Inside the cylindrical cavity, excavators found a fairly number of sites in diverse contexts and with variable offerings; complete human skeleton, an unmodified shell of the Atlantic however, they are quite rare. No Early Classic seated burials or great heart cockle, Dinocardium robustum (Kitty Emery, personal circular stone crypts were excavated at Altar de Sacrificios, the communication 2007), and three Early Classic ceramic vessels. only Pasión-zone site with a sizeable Early Classic burial series Despite modest bone preservation, the skeleton’s articulation (Smith 1972), and none have been found in the Petexbatun sites indicated that the deceased was seated with knees bent to the (Wright 2006). In addition to the Motmot tomb at Copan (Fash chest and hands placed near the face. The spine and cranium and Fash 2000; Fash 1998), Early Classic stone-lined cylindrical were located against the northeastern wall of the cist, with the cists or crypts are known from Chac II (Smyth and Rogart skeleton facing southwest; however, the skeleton may have 2004); both sites have demonstrable material ties to Central shifted somewhat following decomposition, so it is difficult to Mexico or Teotihuacan. Importantly, no circular stone-lined ascertain its exact orientation, which originally may have been cist burials have been documented at Teotihuacan (George more westward. Cowgill, personal communication 2005). Instead, the dominant Three ceramic vessels were located to the southeast of the Early Classic mortuary pattern at Teotihuacan was interment skeleton. Two of the vessels are drinking cups; one is a red- in a somewhat irregular oval earthen pit or fosa; the body was on-cream polychrome, the other a black-slipped vase from the seated vertically with legs tightly flexed and head positioned Balanza ceramic group. The third vessel is a highly polished toward the east (Cabrera Castro 1999; Sempowski and Spence yet unslipped, thin-walled cylinder tripod with a repetitive 1994). This burial pattern was replicated at large Teotihuacan- MAYA ARCHAEOLOGY 30 Itzan Pasión a t n i c a m u s U La Amelia Sayaxche Seibal Altar de Sacrificios Tamarindito n ArroyodePiedra tu n a ac DosPilas L Salinas PuntadeChimino LakePetexbatun Aguateca P a s i ó n 0 3 6 9 12km Cancuen Figure 2. Map showing the location of Punta de Chimino and Aguateca. affiliated centers in western Chiapas (Agrinier 1970, 1975). from Early Classic Teotihuacan where they are believed to have Marine bivalve shells are almost exclusively associated with been locally made (Rattray 2001). Burial PC103’s body position, adult males at Teotihuacan, and direct-rim cylinder tripods with circular shape, and bivalve shell fit within the Teotihuacan well executed plano-relief designs are restricted to elaborate tradition, but the stone-lined circular cist does not. As for body graves (Sempowski and Spence 1994). Tripod cylinder vases orientation, there is another important difference: Teotihuacanos first appeared at Tikal around the time of the famed Teotihuacan face east, not west. entrada of AD 378 (Laporte and Fialko 1990). The repetitive In summary, Burial PC103 appears to be a Lowland Maya serpent motif on the Punta de Chimino cylinder tripod is interment with some Mexican characteristics. Burial PC103 distinctively Maya; however, similar designs have been reported was sealed with thick capstones but was left uncovered by 31 Lori E.