A Precise Chronology for Polynesian Monumental Architecture via Th-230 Coral Dating

在整个旧大陆和新大陆，纪念性建筑的发展，如宗教寺庙和神殿，提供了最明确的考古信号之一，表明复杂的、分层的社会从主要以亲属关系为基础的较简单的社会中出现。特别是，复杂的酋长和由此产生的早期古代国家通常通过与宗教仪式和寺庙相联系的控制等级来行使权力。因此，对这种仪式性建筑进行精确和准确的年代测定，可以提供前所未有的洞察，了解缺乏日历和文字记录的古代社会的经济、社会和政治发展的速度。在与欧洲人接触之前，对波利尼西亚建造的这种不朽建筑进行年代测定的传统方法主要依赖于口头传统和放射性碳年代测定，并辅之以对建筑风格和建造方法的考虑。然而，未经证实的口头传统的准确性是不确定的，关键时间间隔内的放射性碳日期的精度可能会因为将放射性碳日期转换为日历年所遇到的固有困难而严重下降，而且对建筑风格和技术的考虑没有揭示相关社会变化的节奏。然而，在东波利尼西亚，珊瑚与仪式地点和结构之间广泛而古老的联系使得使用适用于珊瑚供品的高级放射性同位素测年技术来精确和准确地确定各种仪式建筑的年代成为可能。该项目的主要研究人员Patrick Kirch教授和Warren Sharp博士最近表明，古代夏威夷人将一种分支珊瑚作为祭品放置在沿海渔业神社和内陆农业寺庙中，通过使用一种基于珊瑚骨骼中微量铀元素在生长过程中放射性衰变的技术，可以测定出大约+或-10年的精确度。考古珊瑚上精致的表面结构被保存下来，这证实了古代夏威夷人收集了活珊瑚。因此，记录珊瑚骨骼生长的珊瑚日期与珊瑚放置在祭坛上或寺庙墙壁上的位置密切相关。因此，Kirch和Sharp提出了一个全面的珊瑚年代测定计划，应用于两个东波利尼西亚社会--夏威夷和社会群岛--的纪念性仪式建筑，那里的仪式建筑与社会政治复杂性的出现密切相关。Kirch在这两个领域都有丰富的经验，我们建议的测年研究将建立在成熟的考古学背景之上，基于他与其他合作者T.Ladeoged(奥克兰大学)、L.Holm和J.Kahn(加州大学伯克利分校博士生)和其他人在之前和正在进行的研究中开发的广泛的测绘、遗址研究和放射性碳测年。拟议研究的广泛影响将包括开发强大的铀衰变珊瑚测年技术在考古学中的应用，其潜在的广泛应用于波利尼西亚和古人类使用活珊瑚的考古研究。这项拟议的研究还将加强对加州大学伯克利分校两名考古学博士候选人的培训，并为加州大学伯克利分校的本科生提供“动手”的实验室研究经验。该项目的协会岛屿部分将与L的波利尼西亚法语大学进行协调，并将加强该机构与美国考古学家最近的学术合作

Throughout both the Old and New Worlds, the development of monumental architecture, such as religious temples and shrines, provides one of the clearest archaeological signals of the emergence of complex, stratified societies from simpler societies organized primarily around kinship. In particular, complex chiefdoms and the early archaic states that emerged from them typically exercised power through a control hierarchy linked to religious ritual and temples. Precise and accurate dating of such ceremonial architecture can therefore provide unprecedented insight into the pace of economic, social, and political developments in ancient societies that lacked calendars and written records. Conventional approaches to dating such monumental architecture constructed in Polynesia prior to European contact have relied principally on the use of oral traditions and radiocarbon dating, supplemented by considerations of architectural style and construction methods. However, the accuracy of uncorroborated oral traditions is uncertain, the precision of radiocarbon dates within key intervals can be severely degraded by the inherent difficulty encountered in converting radiocarbon dates to calendar years, and considerations of construction style and technique do not reveal the tempo of related social changes. In Eastern Polynesia, however, a widespread and ancient association between coral and ritual sites and structures makes it possible to precisely and accurately date a variety of ceremonial architecture using superior radio-isotopic dating techniques applicable to coral offerings. Prof. Patrick Kirch and Dr. Warren Sharp, the principal investigators on this project, have recently shown that a species of branch coral placed by ancient Hawaiians as dedicatory offerings on coastal fishing shrines and inland agricultural temples may be dated with precisions of circa + or - 10 years by using a technique based on the radioactive decay of minute amounts of the element uranium incorporated into coral skeletons during their growth. Preservation of delicate surface structures on archaeological corals selected for dating confirms that ancient Hawaiians collected living corals. Thus the coral dates, which record growth of the coral skeleton, closely correspond to placement of corals on altars or in temple walls. Accordingly, Kirch and Sharp propose a comprehensive program of coral dating applied to monumental ritual structures in two Eastern Polynesian societies, Hawai'i and the Society Islands, where ritual architecture was closely associated with the emergence of sociopolitical complexity. Kirch has extensive experience in both areas and our proposed dating study will build on well-established archaeological contexts based on extensive mapping, site studies and radiocarbon dating developed during previous and ongoing studies by himself, additional collaborators T. Ladefoged (U. of Auckland), L. Holm and J. Kahn (doctoral candidates, U.C. Berkeley), and others.Broader impacts of the proposed research will include developing the application to archaeology of the powerful uranium-decay coral dating technique, with its potentially widespread application to archaeological studies in Polynesia and elsewhere that ancient humans used live corals. The proposed research will also enhance the training of two U.C. Berkeley doctoral candidates in archaeology, and provide "hands-on" laboratory research experience for a U.C. Berkeley undergraduate student. The Society Islands component of the project will be coordinated with l'Universite de Polynesie Francaise, and will enhance recent academic collaborations between that institution and U. S. archaeologist