| 摘要: | 海洋蘊藏豐富的多金屬熱液硫化礦床，而這些海底硫化物資源主要集中在洋中脊和弧後盆地，是海底熱液活動的主要產物，因其富含銅、鋅、鉛、金、銀、鐵等金屬元素而成為一種潛在的海底礦產資源。本計畫為執行中央地質調查所推動之4年期（2016-2019）『臺灣東北海域礦產資源潛能調查—高解析聲納及磁力調查研究』工作，將使用多音束水深系統、高解析聲納系統、磁力儀與海底地震儀等探測儀器與方法，進行多金屬熱液硫化礦床之相關調查研究。本（105）年度計畫之主要調查研究區域位在南沖繩海槽張裂中心的海底火山群。 藉由研究區域的多音束水深資料和高解析聲納資料提供的海底地形圖資，可以判釋南沖繩海槽張裂中心與海底火山群區域內的海底地貌特徵，以瞭解海底火山的分布範圍與型態。磁力資料的收集及分析，則可建立磁化強度分布概況、辨識熱液噴口的位置。海底地震儀所記錄到的地動訊號則可用以評估火成及熱液噴泉活動的活躍程度。綜合這些地球物理研究相關資料，進而瞭解火成岩體與熱液硫化礦床的可能分布、海底淺部地層沉積物之沉積特徵及特殊構造現象，並研判熱液硫化礦床在地層中可能的通道或路徑。再進一步配合地球物理、地球化學及海床觀測等探測結果，評估多金屬熱液硫化礦床的分布範圍及資源潛能。此外，本計畫也將同時建置東北海域火成及熱液作用活躍區的多音束精密水深資料，並繪製全區水深圖，作為相關研究所需之精密海底地形圖，建立東北海域基礎地質資料。 ;Deep-sea hydrothermal vents, found along mid-ocean ridges and back-arc basins, spew out sulfide-rich fluids from which metal sulfides precipitate. Due to the rich concentrations of metals , such as copper, zinc, lead, gold, silver, and iron, the submarine hydrothermal activity area become a potential undersea mineral resources. This proposal aims to execute the 4-years (2016-2019) program “Investigation of Mineral Resource Potential in the Offshore Northeastern Taiwan—High-resolution Sonar and Magnetic Surveys”, funded by the Central Geological Survey (CGS). The key aspect of the proposed projects is to collect the high-resolution sonar (including sub-bottom profiler and side-scan sonar), multi-beam echo sounder data, magnetometer and ocean bottom seismometer data for the investigation of hydrothermal vents characteristics and activity. The target area of this year is located in the Okinawa Trough, offshore NE Taiwan, including the active submarine volcano group. Based on the high-resolution bathymetric data, the geologic features related to diking, faulting, and lava flow emplacement would be identified. The distribution of hydrothermal systems could provide the physical pathway for fluids from the subsurface to the seafloor. The high-resolution magnetic field mapping can image the effects of hydrothermal venting on the crust - by finding areas where the corrosive vent fluid has demagnetized the crust through chemical alteration. The seismic ground movement recorded by the ocean bottom seismometer should provide the activity level of such hydrothermal system. The combination of all these geophysical and chemical result, we can get more understanding about the sedimentary features in the submarine strata, the distribution of the volcanic rock and hydrothermal deposits, and the possible fluid pathway underneath the research area. Then, we estimate the potential of the mineral resource by integrating our results with chemical observations. In addition, the detailed multi-beam bathymetry data acquired during this project will also be used to compile a regional bathymetry map, as a part of the submarine geological map in the area. ;研究期間：10501 ~ 10512 |
