- 期刊
台灣西南海域義竹斷層是否為古第三紀台南盆地的邊界斷層？
Is the Yi-Chu Normal Fault the Border Fault of the Paleocene Tainan Basin, Offshore SW Taiwan?
摘要
古第三紀台灣西南海域－中國大陸的裂谷盆地自珠江口盆地向東北方向發育，地殼張裂的時間分別為古新世與始新世，依據拉張盆地的觀念，邊界斷層的一側是在中國大陸的一方，邊界斷層的斷面向東或東南方向傾斜；則在台灣的這一方，邊界斷層的斷面應是向西或西北方向傾斜。義竹斷層是一個斷面向南（陸上）或東南方向（海域）傾斜，與剛才所指的方向完全相反，因此，義竹斷層在白堊紀至漸新世時期應不是台南盆地的邊界斷層。那古第三紀台南盆地的邊界斷層應在何處？ 本研究透過台南盆地西部井下地質、震測資料解釋、建立台南盆地西部地體架構的研究認為台南盆地西部古第三紀的邊界斷層位於JB-1井之北側。與珠江口盆地間之構造型式是左向滑移之關係。
並列摘要
The rift basin from the Mainland China to the offshore Southwestern Taiwan was developed northeastward from the Pearl River Mouth Basin during the Paleocene and the Eocene respectively. According to the concept of rift basin, since the border fault near the Mainland China dips to the east or southeast, then the one near Taiwan should dip to the west or northwest. In fact, the Yi-Chu Fault dips southward on land or southeastward at sea, and does not coincide with the dipping direction predicted above. Thus, the Yi-Chu Fault shall not be the border fault of the Tainan Basin from the Cretaceous Period to the Oligocene Epoch. Then, where is the border fault of the Tainan Basin during the Paleocene? Using the subsurface geology and seismic data interpretation, this study has established the tectonic framework of the Western Tainan Basin, and concluded that the border fault of the Paleocene Tainan Basin is located to the north of Well JB-1. There is a left-lateral strike-slip fault between the Tainan Basin and the Pearl River Mouth Basin.