臺灣中部南港溪－濁水溪地區的地質構造研究

A Study on Geological Structures in Areas of the Nangkang River and the Choushiui River, Central Taiwan

林啟文(Chii-Wen Lin) ； 周稟珊(Ping-Shan Chou)

《臺灣鑛業》 68卷3期 (2016/09) Pp. 29-50

摘要

本研究調查南港溪與濁水溪流域白冷層與其相當地層的層序與地質構造，以期瞭解雪山山脈的地質構造特性。經地層的岩性特徵、層位與放射性定年結果比對，水長流層時代可能向下延伸至漸新世早期甚至更老，因此可能對比地利斷層以東的廬山層及其下伏包括眉溪砂岩與佳陽層，而達見砂岩（包含玉山主山層）只可能對比白冷層上部，十八重溪層則可能對比白冷層下部。經由地層與中尺度地質構造的研究，雪山山脈包含兩個複向斜與一個複背斜構造，若以地層對比的結果推論，那麼地利斷層東側構成最東側的另一個複背斜，而該斷層可能是截切複背斜前翼的截穿逆衝斷層。地利斷層以東，依序出露的地層構成同斜構造，與地利斷層以西的複向斜與複背斜構造明顯不同。

關鍵字

雪山山脈 ； 白冷層 ； 地質構造 ； 南港溪 ； 濁水溪

並列摘要

The present study focuses on the sequence and structural characteristics of the Paileng Formation and its equivalents in order to unravel the structural pattern of the Hsuehshan Range. Based on the lithologic characteristics of strata and radiometric dating data, the Shuichangliu Formation has the age from late Oligocene to Early Oligocene or even older, can be correlated to, in a descending order, including the Lushan Formation, the Meichi Sandstone and the Chiayang Formation. The upper part of the Paileng Formation which underlies the Shuichangliu Formation is correlated to the Tachien Sandstone and the Yushanchushan Formation, while the latter is suggested to be abandoned. In addition, the lower part of the Paileng Formation is correlated to the Shihpachungchi Formation. According to the stratigraphic sequence and the mesoscale structures, it is suggested that the study area of the Hsuehshan Range is constituted by two synclinoria and one anticlinorium. East of the Tili fault constitutes another easternmost anticlinorium, and the fault may serve as a break-through thrust which cutting the frontal limb of the anticlinorium. Strata exposed in the eastern limb of the former anticlinorium constitute a homocline structure which is obviously different from the area west of the Tili fault.

並列關鍵字

Hsuehshan Range ； Paileng Formation ； Geological structure ； Nankangchi area ； Choushuichi area