| 摘要: | 以地質圖呈現區域地質與構造可以幫助地質學家了解整個海岸山脈的地體架構。過去地質圖的產製工作主要透過直接的野外露頭觀察與解釋進行，雖然傳統的調查方法所獲得的資料可靠，但受限於海岸山脈地形險阻以及植被覆蓋密集等限制，使得大規模有效的調查成為困難，繪製高解析度且可靠的地質圖也充滿挑戰。近年來光達與遙測技術的進步，使得在合理資源的使用下應用空載光達產製高解析度的數值高程模型成為可能，地質學家也意識到使用不受植被影響的數值高程模型可以直接用做於地質的判釋與分析。本研究使用2公尺解析度的數值高程模型，針對海岸山脈秀姑巒溪以北的區域進行地質判釋和分析。研究流程大致包含數值高程模型視覺化的資料處理、三維製圖工作包含岩層等線型的判釋以及構造的位態等分析、野外調查工作包含傳統方法以及無人飛行載具的空拍等地質資訊的查核、並綜合以上資訊互相核實，以產製一張1:50000的海岸山脈地質圖及相關剖面。研究結果去除資料品質不佳者共判釋四千餘條代表岩層的線型構造，並提供研究區域內分布均勻且高密度的位態資料；研究區域內出露由老至新包含都鑾山層、蕃薯寮層、八里灣層、以及舞鶴礫岩等地層，構造分析的部分顯示區域內存在九條斷層，將研究區域區分為七個斷塊，由地層與斷塊間的關係最終認為海岸山脈北段出露共34的地質單位；此外區域內共存在七條褶皺，本研究詳細分析每條褶皺的幾何形貌，其中奇美向斜更進一步依其幾何變化由南至北分為六段。研究結果提供更可靠且更精準的地層單元邊界，並確立了例如十二分坑斷層、水璉斷層、以及灣潭斷層的存在。構造分析也由於均勻分布且高密度的位態而在區域尺度下更具有代表性。地質圖的單元更是基於地層間的層位關係更詳細的將地層分層，也加上不同岩相的測繪與查核，使地質圖同時包含時間與沉積環境兩個維度的資訊。本研究也確立了海岸山脈北段構造的幾何形貌，可提供未來建立整個造山的架構的時空分析有更全面的資訊。;Presenting regional geology and structures through geologic maps can assist geologists in understanding the tectonic framework of the entire Coastal Range. In the past, the production of geologic maps primarily relied on direct field observation and interpretation. Although data obtained through traditional survey methods are reliable, due to rugged terrain and dense vegetation cover, that decrease the effectiveness of large-scale surveys in Coastal Range. Since of that, it is challange to generate high-resolution and reliable geologic maps. In recent years, advancements in LiDAR and remote sensing technologies have made it possible to produce high-resolution digital elevation model. Geologists have alse recognized the value of utilizing vegetation-independent digital elevation model directly for geological interpretation and analysis. In this study, 2-meter resolution digital elevation model was adopted to conduct geological interpretation and analysis in the northern part of Coastal Range. The research process involved various steps, including data processing to visualize the digital elevation model, three-dimensional mapping tasks encompassing the interpretation of lineament such as rock formations and the analysis of structural geometry, field surveys utilizing both traditional methods and aerial surveys with unmanned aerial vehicles for verifying geological information. Integrating these information and generate a 1:50,000-scale geologic map and profile of the Northern part of Coastal Range. The research results involved the interpretation of over 4000 lineament representing rock formations after excluding data of poor quality. The study provided uniformly distributed and high-density attitude data within the research area. The lithostratigraphy unit exposed in the study area include Tuluanshan Formation, Fanshuliao Formation, Paliwan Formation, and Wuho conglomerate ranging from the oldest to the youngest. The structural analysis suggest the existence of nine faults, leading to the subdivision of the study area into seven fault blocks. Considering the distribution of rock formation and fault blocks, a total of 34 geological units were identified in the Northern part of Coastal Range. Furthermore, the study identified seven folds with detailed analysis of geometry, with the Chimei Syncline further divided into six segments based on its geometric variations from the spatial characteristics. The results have contributed to more reliable and precise mapping of lithostratigraphic unit, establishing the existence of structures such as the Shierfenkeng Fault, Shuilian Fault, and Wantan Fault. The structural analysis holds greater representativeness at the regional scale, benefitting from the uniformly distributed and high-density structural attitude data. Based on more detailed mapping and verification of different lithofacies by field surveys, the geologic map provide more comprehensive information in both temporal and depositional environment changes. Furthermore, this study has solidified the geomety in the Northern part of the Coastal Range. This provides a more comprehensive information for future spatio and temporal analysis aiming to establish the framework of the orogeny. |
