臺灣雪山西稜線史前石屋遺址群的年代及選址探討

Dating and Siting of the Prehistoric Stone Houses on the West Ridge of Syue Mountain in Taiwan

雪霸國家公園之雪山西稜於海拔2,800至3,600公尺間沿線分布多處史前石屋遺址。鄰近的泰雅族及賽夏族曾流傳，於其傳統領域內居住著其他異族群。然而，考古證據的缺乏使得這些史前石屋遺址的所屬族群、選址與建造原因至今仍未釐清。放射性碳14定年結果表明遺址年代屬金屬器時代晚期。石屋遺址的建築係由塊狀、長方體或厚板狀之變質砂岩所堆疊而成。基於建材鑑定與地層岩性的對比，不排除為就地取材。根據空載光達測製之1公尺數值地形模型顯示，這些石屋遺址多數建於雪山西稜線的平緩崩塌地，且鄰近於溪流最上游，選址可能與地勢及取水考量有關。值得注意的是多戶數的大型遺址群，如志樂溪遺址、火石山及奇峻山遺址，皆分布於志樂溪不同支流的上游處，暗示志樂溪一帶可能為選址的核心區域。其他如翠池、可汗池、拾丸谷遺址為孤立或零星石屋，其特徵為周邊皆有高山湖泊。大型遺址群中，奇峻山遺址年代（西元648-718）早於志樂溪與火石山遺址（西元1292-1400）。這兩個年代皆對應著古氣候史上較為溫暖的時期，尤其後兩個遺址年代介於中世紀暖期與小冰河期的過渡期間，推測這些史前聚落可能伴隨著小冰河期的到來而遷離。

Numerous prehistoric stone houses are located along the west ridge of Syue Mountain (2,800-3,600m above sea level) in Shei-Pa National Park in Taiwan. According to legends, people of different ethnic groups dwelt in the traditional territory of Atayal and Saisiyat peoples adjacent to the west ridge. However, because of the lack of relevant archaeological evidence, the sites and reasons for the construction of these prehistoric stone houses, as well as the ethnic groups by which they were constructed, remain unknown. The results of carbon-14 dating indicated that these houses were constructed in the Late Metal Age. The structures of these stone houses consist of different shapes of metasandstone blocks, such as cuboids and slabs. According to the building materials and a lithologic comparison of the strata, the materials were presumably collected on site. According to images from a 1-m digital elevation model (DEM) constructed using airborne light detection and ranging (LiDAR), these stone houses were mostly constructed on gentle landslide terrain along the west ridge of Syue Mountain and adjacent to the uppermost streams of Zhile Creek. Therefore, the sites were probably selected on the basis of topography and water accessibility. Notably, the large-scale sites with numerous households, such as the Zhile Creek, Huoshi Mountain, and Qijun Mountain sites, are all distributed around the upper-stream tributaries of Zhile Creek, suggesting that the construction of the houses was most concentrated around the creek. At other sites, such as the Cuei Pond, Kehan Pond, and Shi-Wan Valley sites, the stone houses are isolated or dispersed and surrounded by high mountains and lakes. Among the large-scale sites, the Qijun Mountain site (648-718 A.D.) predates those of the Zhile Creek and Huoshi Mountain sites (1292-1400 A.D.). The construction of the Zhile Creek and Huoshi Mountain sites coincided with relatively warm climatological periods, specifically during the transition period between the Medieval Warm Period and the Little Ice Age. Therefore, these prehistoric settlements may have moved away following the arrival of the Little Ice Age.