[H-CG30] 考古科学：地球科学と考古学

[HCG30-P12] カナリア諸島テネリフェ島の先スペイン期における黒曜石利用：現地踏査と元素分析による黒曜石産出地推定の暫定結果

*中沢 祐一¹、ベガ・マエソ クリスティーナ²、隅田 まり³、カルモナ・バレステロ エドワルド⁴、リゼト ジョン⁵、ベルソーサ・オルダス アルベルト⁴、直江 康雄⁶、研晶 土肥⁷、新家 水奈⁷、デル・アルコ・アギラール メルセデス⁸、シュミンケ ハンス-ウルリッヒ³ (1.北海道大学大学院医学研究院、2.カンタブリア大学、3.キール大学ヘルホルツ海洋科学研究所、4.ブルゴス大学、5.ネブラスカ州歴史協会、6.千歳市教育委員会、7.北海道埋蔵文化財センター、8.テネリフェ考古博物館)

キーワード：カナリア諸島、テネリフェ島、踏査、黒曜石、EPMA、L-ICP-MS

The Canary archipelago comprises seven major islands located approximately 27 – 29 degrees N, stretching for 490 km on the eastern Atlantic, off the shore of northwestern North Africa. Tenerife, the highest and largest volcanic island among the Canary Islands was occupied by the indigenous people called the Guanches, until the 15^th Century when the Spanish colonizers arrived. In November 2016, a group of the authors have conducted a pedestrian survey of obsidian outcrops and archaeological sites on the surface of Tenerife, as well as an observation on excavated obsidian artifacts from major archaeological sites at the Tenerife Archaeological Museum. The purpose of this research was to investigate the human exploitation of obsidian to elucidate how the Guanches survived in this active volcanic landscape during the Pre-Hispanic times. Island of Tenerife provides an ideal setting to address this research question, because of its unique biogeographic settings: diverse ecological zones characterized by northern humid region and southern dryland, and altitudinal difference created by Mt. Teide (3718m asl) in the middle of the Island. The survey was conducted at the southern dryland (“barranco”) of Tenerife, and we identified a total of 32 artifact scatters, principally consisting of obsidian artifacts, pot sherds, and marine shells. Among the surface scatters, 29 of them have obsidian artifacts. Besides these archaeological surface scatters, we also located three obsidian outcrops: Tabonal Negro (a part of phonolitic dome in Mt. Teide), Tabonal los Guanches (northern skirt of Mt. Teide), and Chalco de Viento (north coast). Some obsidian artifacts were collected for further geochemical study of obsidian and hydration measurements. Besides, obsidian artifacts from Estacas 1 and Guargacho were also sampled for comparison. Among these samples, we specifically chose 11 samples from a combination of surface localities, excavated archaeological sites, and obsidian outcrops. In this paper, we report a preliminary result of EPMA and Laser ICP-MS analysis of these obsidian samples. The result will provide a variation in geochemical signatures of obsidian and an implication of Pre-Hispanic human use of obsidian in Tenerife.