- 期刊
縱谷斷層南段的階地對比及新構造運動研究
The Study of River Terraces and the Neotectonic Implications of the Southern Huatung Longitudinal Valley
摘要
本區的階地分布及特徵在歷年來的調查已有相對完整的成果，然而在階地對比及地形演育過程方面卻出現了不同的看法。由於對比結果的不同會造成在斷層的活動性推論結果的差異，因此，本文試圖由野外進行階地等地形面的調查、對比分析，再配合現有之階地定年資料加以探討斷層及其他構造線的活動性。研究結果顯示：1.在階地對比方面，依紅土分布階地比高、崖高及階地類型等特徵可將鹿野溪南、北岸及卑南溪東岸之階地均對比為四期河階發育，由定年資料可知卑南溪東岸階地的第二期發育年代約為2000-3000yr B. P.，第三期約在1000 yr. B. P.，第四期則在近千年之內發育而成；2.在構造抬升速率方面，依據年代及比高、崖高等資料可推估鹿野溪南岸的抬升量大於北岸；3.由利吉斷層東西兩側的一帶的抬升速率推估發現利吉斷層在全新世的最近期應有活動，應歸於最近一萬年以內曾活動的『第一類活動斷層』。
並列摘要
In recent fieldworks and researches, the investigation of the distrubution and characteristics of the terraces in the area of the Southern Huatung Longitudinal Valley has already obtained a relatively complete results, however, there still exist very different views about the river evolution and the tectonic activities in this area. In this study, we attempt to raise a more detail investigated result and terraces correlations, and infer the different result of the river evolution. The result showed that four stages of terraces were developed in the area of the Southern Huatung Longitudinal Valley. The highest surface is covered by lateritic soils and have been deformed by active faults and folds. the second phase era is about 2000-3000yr B.P., the third is about close to 1000 yr.B.P. and the fourth maybe occurs in recent centuries . According to the datas of terraces, datings, cliffs heights, and the forms, we can indicate that the tectonic uplift in south river bank of Luya river is higher than of north. In tectonic uplift rate, we estimating that the uplift rate of south shore of the Luye River was larger than the north shore, and the Lichi fault should classified as an active fault of the first category.