清水海岸平原之地下地質

Subsurface Geology of the Ching-shui Coastal Plain, Western Taiwan

謝英宗(Ying-Tzung Shieh)

《國立臺灣博物館學刊》 59卷2期 (2006/12) Pp. 1-17

摘要

經濟部中央地質調查所執行「臺灣地區地下水觀測網」水文地質調查研究，於2005年在臺中縣梧棲國小鑽一口深井，作為清水海岸平原地下地質研究之用。本文利用該鑽井岩心沉積物從事古生物學研究並探討本區之古環境。超微化石生物地層和放射性碳十固定年結果顯示，該地區在第四紀中期至今至少有二次海進和一次的海退。岩心下段所代表的第一次海進時代和原因並不清楚，值得更進一步探討。岩心上段所代表的第二次海進應屆全新世中期全球隨著末次冰盛期之後的氣候暖化導致海平面上升所造成。

關鍵字

清水海岸平原 ； 地下地質 ； 超微化石 ； 古環境

並列摘要

For understanding subsurface geology and stratigraphic correlation of hydrological in vestigation of the Underground Water Observation Network of Taiwan, there was an observation well drilled at Wu-chi primary school campus by the Central Geological Survey, MOEA, in 2005. Based on nannofossil biostratigraphy and AMS C^(14) dating results, there have been two transgression and one regression cycles since Mid-Quaternary in the Ching-shui coastal plain of mid-western Taiwan. The first transgress ion phase was identified by nannofossil in the lower sediments of the observation well; however, the age and cause of this transgression event are not clearly understood yet. The second transgression period was recorded in the upper sediments of the observation well, according to the nannofossil biostratigraphy and AMS C^(14) dating results; this second transgression period occurred during the Holocene Optimum Period. Between the first and second transgression events evidenced in the observation well, a regression phase identified by deposited terrestrial facies sediment was apparent.

並列關鍵字

Ching-shui coastal plain ； subsurfcae geology ； nannofossil biostratigraphy ； paleoenvironment ； Taiwan