頁籤選單縮合
題名 | 花東海岸全新世地殼上升速率的再檢討=A New Version of Holocene Tectonic Uplift Rates Along the Hua-Tung Coast of Eastern Taiwan |
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作者姓名(中文) | 謝孟龍; 劉平妹; | 書刊名 | 經濟部中央地質調查所彙刊 |
卷期 | 23 2010.12[民99.12] |
頁次 | 頁165-199 |
分類號 | 351.3 |
關鍵詞 | 地殼隆升速率; 海階; 花東海岸; Tectonic uplift rate; Marine terrace; Coastal range; |
語文 | 中文(Chinese) |
中文摘要 | 本研究利用定年大於3 ka的海相、濱海相沉積物(包括原地生長的珊瑚與鑽孔貝),並採用來自澎湖(0-5 ka)、新加坡(6-9.5 ka)與Sunda Shelf(11-20 ka)的古海水面曲線,來計算花東海岸的地殼隆升速率。計算結果發現:海岸大部分的區段(新社以南),都擁有每年至少四、五公厘的隆升速率。這段快速隆升的海岸呈現兩個北緩南陡、不對稱的大型背斜:背斜軸部分別位於長濱、膽曼之間以及杉原、富山一帶;前者隆升速率達每年八公厘,後者約每年一公分多。疊加在這兩個主要背斜之上仍有幾處小幅度的褶皺。以上構造形態大致和此間海階地形資料吻合(或至少不違背),但後者呈現更為複雜的序列與形態,暗示除了構造隆升之外,更多的因素(如基盤岩性與沿岸沉積物供應)也影響著該海岸的形貌與演育。本研究所得到的兩個主要背斜大致對應海岸山脈南、北不同的地形區塊:位於北方的主要背斜包含幾個雁行排列的火山岩山脊,南方的背斜則對應泰源盆地及其東緣的弧形火山岩山脊。幾處隆升速率出現局部轉折的地點也發生在不同種類基盤岩石的交界地帶,且泥岩區(包括利吉混同層)的上升速率均大於火山岩區者。這些現象似乎暗示:花東海岸新期的構造運動相當程度受到原本島弧系統岩性分布的影響。 |
英文摘要 | Dated (>3 ka) marine/coastal sediments and in-situ organisms (mainly corals and boring shells) were used to calculate tectonic uplift rates on the Hua-tung coast fringing the Coastal Range in eastern Taiwan. The global sea-level data applied for this calculation include those derived from Penghu Islands off Taiwan (0-5 ka), Singapore (6-9.5 ka), and Sunda Shelf (11-20 ka). The results show that, except for its northernmost 32-km long section, the remaining coast has been uplifted at rates of 5-10 mm/yr, on which two anticlinal structures with the axes located north of Tan-man (on the middle part of the coast) and around Fu-shan (on the southernmost part of the coast) are recognized. This uplift pattern is generally consistent with the elevation pattern of marine terraces or the highest marine sediments exposed along the coast. However, the marine terraces show complex sequences in detail, demonstrating the importance of factors other than tectonic uplift, such as bedrock type and along-shore sediment transport, in governing the local morphology and evolution of the coast. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。