台灣西南部麓山帶下部上新統之沉積環境及地層對比研究

Sedimentary environments and stratigraphic correlation of the lower Pliocene Series in the southwestern foothill, Taiwan

廖明威(Ming-wei Liao)

指導教授 ： 林殿順

國立中央大學/地球科學學院/地球科學系/碩士(2014年)

摘要

台灣西南部岩層岩性側向變化大，地層間對比不易。本研究於嘉義台南麓山帶地區，研究早上新統之沉積環境及地層對比，共有四個剖面，包括內麓山帶沄水溪剖面，其地層為中崙層、鳥嘴層、沄水溪層；及內麓山帶大埔橋剖面、曾文溪剖面、後堀溪剖面地層之鹽水坑頁岩、隘寮腳層與茅埔頁岩。本研究以三個面相進行：1、解釋沉積環境：將野外露頭區分出十七個岩相，包括二個泥岩相、五個砂泥紋層相、六個砂岩相、MTD及泥粒相，組合岩相為：遠濱相、遠濱過度帶、濱相、水道主導濱相、水道主導遠濱過渡帶，沉積環境則分屬波浪影響的開放淺海系統，及水道主導淺海系統。2、超微化石生物地層：鑑定超微化石種屬，訂定超微化石帶，指準化石Reticulofenestra pseudoumbilica之末現面NN15與NN16之介面，位於鳥嘴層與隘寮腳層最頂部。3、層序地層，以沉積環境為基礎，利用次層序疊加法推演層序地層進行地層對比，由中崙層、鳥嘴層至沄水溪層及鹽水坑頁岩、隘寮腳層至茅埔頁岩，共劃分三次層序循環，剖面間層序及體系域亦可互相對應。本研究顯示藉由生物地層、岩性地層及層序地層對比，顯示台灣西南部內外麓山帶早上新世兩套地層之，中崙層與鹽水坑頁岩對應，鳥嘴層則相當於隘寮腳層。

關鍵字

西南部麓山帶 ； 地層對比 ； 沉積環境 ； 鳥嘴層 ； 隘寮腳層 ； 下部上新統

並列摘要

Lithosfacies change dramatically //in Chiayi Tainan area southwestern Taiwan foothill. The objective is to study sedimentary environments on four outcrop section and correlation between two // stratigraphic system of lower Pliocene series. Formations of Yunshuichi section from are Chunlung formation, Niaotsui formation and Yunshuichi formation in outer foothill. Formations of Tsenwenchi Hokuchi and Dapu section are Tangenshan sandstone, Yenshuikeng shale, Ailiaochiao formation and Maopu shale belong to inner footfill.
By employing Facies analysis identify 17 facies combine to 6 sedimentary environments：upper shoreface, lower shoreface, offshore transition, offshore, channel-dominated shoreface channel-dominated offshore transition belong two sedimentary systems 1.wave dominated shallow marine 2. Channel dominated shallow marine system. Result of calcareous nannofossil shows LOD datum of Reticulofenestra pseudoumbilica boundary between NN15 and NN16 (3.75Ma) // locate at top of Ailiaochiao Niaotsui formation. Sequence stratigraphy 3 sequence from Chunlung formation to Yunshuichi formation and Yenshuikeng shale to Maopu shale based on facies analysis. According to lithostratigrahy, biostratigraphy and sequence stratigraphy chunlung formation correlate with Yenshuikeng shale and Niaotsui formation correlate with Ailiaochiao formation.

參考文獻

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