中大沉積暨盆地研究室Sedimentology and Basin Research Group, NCU

~歡迎轉發~

英國牛津大學 Prof. Watts來台訪問，有一場短期課程，二場演講(如下)。歡迎地科界學生、朋友踴躍參加。

2024/10/28 (Monday): 2-5 PM
Short course (S135, Dept. Earth Sciences, NCU)
Plate Flexure, Isostasy and Earth's Gravity Field
此短期課程需報名：
https://docs.google.com/forms/d/e/1FAIpQLScxMynx53FDV1ye-6H_CelS2wWgZtSwfqTE-xjBcxpFKOZC6g/viewform

2024/10/29 (Tuesday): 2-3 PM
Lecture (Second Floor Lecture Hall, Institute of Earth Sciences, Academia Sinica)
Plate Flexure and the Origin of the Sedimentary Basins

2024/10/31 (Thursday): 4-5 PM
Lecture (S135, Department of Earth Sciences, National Central University)
Mountains in the Sea

詳細摘要可以參考演講網頁：
https://basin.earth.ncu.edu.tw/Meetings/2024-Watts-Lectures/Watts-Lectures-in-Taiwan.htm

或是以下資訊：
2024/10/28 (Monday): 2-5 PM
Short course (S135, Dept. Earth Sciences, NCU)
Plate Flexure, Isostasy and Earth's Gravity Field

The aim of this short course is to explore the phenomenon of plate flexure and how it has impacted our understanding of the geological record, the rheological properties of Earth’s tectonic plates, and the geoid and gravity field.

In Part 1, we will discuss the historical development and the theory that underlies plate flexure and give examples of some of the loads that drive flexure at ocean islands and seamounts, large river deltas, and deep-sea trenches and outer rises.

In Part 2, wewill discuss how the lithosphere responds to loading on short-term (i.e. > tens of years) seismic to long-term (i.e. > 1 Ma) geologic time-scales and give examples of how observations of flexure have been used to infer the relationship between the
plate rigidity and age, constrain brittle and ductile flow laws derived from experimental rock mechanics data, and estimate the rate at which isostatic adjustment takes place in different tectonic settings.

Finally, in Part 3 we will examine the relative contribution of plate flexure and mantle dynamics in contributing to Earth’s gravity and topography fields. We will show that the long wavelength gravity field (i.e. wavelength > ~1000 km) cannot be attributed to plate
flexure and is most likely caused instead by some form of mantle dynamics and that stratigraphic data (e.g. through global mapping of hiatuses, pinch-outs, onlap and offlap patterns) offers the most potential to isolate the magnitude of any dynamically driven topography.

2024/10/29 (Tuesday): 2-3 PM
Lecture (Second Floor Lecture Hall, Institute of Earth Sciences, Academia Sinica)
Plate Flexure and the Origin of the Sedimentary Basins

Plate flexure is a universal phenomenon that describes how planetary lithospheres responds to large loads imposed on their surface such as those associated with glaciation/deglaciation, volcanism and sedimentation. Backstripping of well data reveals that sediment loading, for example, contributes significantly to the formation of rift-type basins, amplifying the subsidence caused by stretching, heating and thinning of the lithosphere during rifting by up to a factor of 2.5. The actual response depends, however, on knowing the sediment thickness at the time of deposition, the
paleobathymetry, the sea level and, importantly, the thermal and mechanical properties of the underlying lithosphere. Simple models of progradation and aggradation show that sediment-driven plate flexure contributes to the stratigraphic ‘architecture’ of sedimentary basins, including patterns of onlap and offlap. In addition, process-oriented gravity and flexure modeling of sedimentary basins shows
that the effective elastic thickness, a proxy for the long-term strength of the lithosphere, increases with age since rifting and is given approximately by the depth to the 450o C isotherm based on cooling plate models. Arguably the best examples of flexure are foreland-type basins that form in front of migrating thrust/fold loads. Simple models show that flexure produces a wedge-shape depression and a flanking bulge and controls the depth and width of the depression and drainage patterns in bulge regions. The lithosphere retains a ‘memory’ of past loading events, which
allows sedimentary basins to morph from rift-type to foreland-type and for the strength of the lithosphere acquired in one event to be inherited by a future event. Flexure likely plays a significant role in the development of cratonic-type basins although their association with thick seismic lithosphere, long-lived stratigraphic sequences, little or no rifting and a deep-sourced gravity anomaly make it difficult to resolve.

2024/10/31 (Thursday): 4-5 PM
Lecture (S135, Department of Earth Sciences, National Central University)
Mountains in the Sea

One of the mysteries of the sea are the large number of seamounts that rise on the seabed and, in a few cases, break surface to form oceanic islands. Volcanic in origin, seamounts are widely scattered throughout the world’s ocean basins, especially in the Pacific. Recent estimates suggest that there maybe as many as 200,000 seamounts with heights that range from 0.1 to 6.7 km above the surrounding seafloor. Seamounts are generally circular in shape,
have pointed, star-shaped, curved, or flat tops, and are often capped by a coral reef. They are of geological interest because they record the motions and the mechanics of Earth’s tectonic plates and the magmatic ‘pulse’ of its deep interior. They are also significant as ocean ‘stirring rods’, biodiversity ‘hotspots’, and hazards for earthquakes and tsunamis, submarine landslides,
and navigation. Statistical studies suggest that there are as many as 24,000 seamounts higher than 1 km still to be discovered. The charting of these seamounts and the determination of their morphology, structure, and evolution is one of the many challenges facing marine geologists in the future.

2024/3/19
德國萊布尼茲應用地球物理研究所（Leibniz Institute for Applied Geophysics, LIAG)研究員Christian Zeeden來訪，洽談台灣前陸盆地科學深鑽井可能性。

Christian 是循環地層學（cyclostratigraphy)代表性學者，擅長用統計方法找出地層紀錄的規律與週期性，由地層紀錄解析古氣候、天文軌道週期對地球氣候的影響。

萊布尼茲應用地球物理研究所：
https://www.leibniz-liag.de/en/home.html

Christian Zeeden循環地層：
https://blogs.egu.eu/divisions/ssp/author/zeeden/

#碳封存及地熱研究中心

【徵求單位】國立中央大學碳封存及地熱研究中心(主任：林殿順 教授)
【職缺】博士後研究員2名、研究助理2名、行政助理1名
【工作內容】碳封存及地熱研究中心為新成立單位，目的為協助國家及企業減碳並開發地熱能源，為國家「2050淨零排放」目標努力。在碳封存研究部分，本中心致力於二氧化碳地質封存之三維地下地質模型建置、二氧化碳封存量評估、封存場址規劃、二氧化碳灌注及監測技術建置與開發、二氧化碳地下移棲模擬、風險評估與管理等工作。在地熱研究部分，於地熱潛能區，進行地表地質調查與地球物理探勘、地下地質模型建置、地熱模型建置以及地熱流體模擬等工作。徵聘人員為研究中心編制內約聘人員。除行政助理外，博士後及研究助理將負責研究計畫資料收集、處理、解釋等研究相關工作，協助報告撰寫及其他交辦事項。除了1名研究助理工作地點為國立成功大學外，其餘人員工作地點為國立中央大學。
【工作時間】中華民國111年9月起
【工作待遇】比照國立中央大學專任人員報酬標準表
【應徵條件】
A. 博士後研究員(2名)
1. 具國內外地球科學、水文地質、環境地質等相關系所博士學位。
2. 認真、負責、誠懇，具溝通協調能力，能完成交辦工作。
B. 研究助理(2名)
1. 具國內外地球科學、水文地質、環境地質等相關系所碩士學位。
2. 認真、負責、誠懇，具溝通協調能力，能完成交辦工作。
C. 行政助理(1名)
1. 具國內外地球科學、水文地質、環境地質等相關系所之學士學位或教育部認可之國內外大學學士學位。
2. 認真、負責、誠懇，具溝通協調能力，能完成交辦工作。
【應徵方式】請將附照片之履歷寄至[email protected]，主旨註明「應徵碳封存及地熱研究中心專任人員」。 截止時間為111年8月31日中午前。

Open access to full-texts for all journals collected in Lyell Collections:
https://www.lyellcollection.org/

Full access is available in Taiwanese academic institutions until 30 September 2021.

恆春 消失的 "滿州湖"!

中大沉積暨盆地實驗室
期刊論文發表：台灣南部造山帶伴隨海岸抬升的的暫態地形演育
Giletycz, S.J., Lin, A.T.*, Yamada, K., Wang, L.-C., Chien, C.-W., Lou, J.-Y. et al. (2021) Ephemeral landform development following rapid coastal uplift in the southern orogen of Taiwan. Earth Surface Processes and Landforms, 1–16, DOI:10.1002/esp.5183.

Publisher website:
http://doi.org/10.1002/esp.5183

Full-text download:
http://basin.earth.ncu.edu.tw/publications/papers/Giletycz_etal_2021_Ephemeral%20landform%20development%20Hengchn%20Peninsula_online%20version.pdf

台灣南部恆春半島在地質史上是剛從海裡抬升、出露至地表的地形，這地形承接了原本還是海床的地形，抬升至地表後，因陸上侵蝕作用，將地形塑造成陸上造山帶的地形。所以幾萬年來的恆春半島有所謂的「暫態地形」演育。中大沉積暨盆地實驗室承接中興工程的研究計畫，協助分析於恆春半島港口溪鑽探的幾口全新世沉積物鑽井。鑽井分析結果(沉積相、介形蟲、有孔蟲、花粉)，加上Giletycz博士早期於恆春跑野外所發現的「滿州湖」沉積物，二項不同地質證據，指出在6000年前，港口溪流域其實是一個大湖泊，稱為「滿州湖」。位於恆春斷層上盤的滿州湖，因為斷層抬升與往東傾斜作用，使得在約6000年前，湖泊潰堤消失，湖水往東、向太平洋流出，古代的「滿州湖」成為今日的港口溪流域。

本研究發表於SCI Q1期刊Earth Surface Processes and Landforms。本文寫作過程中，西班牙Prof. Dennis Brown以及法國Prof.Frederic Mouthereau給了極多的幫助。

本文第一作者是波蘭籍張文和博士(Dr. Slawomir Jack Giletycz，人稱Jack)。他自2004年來台，會說流利的國語，還與屏東排灣族長老成拜把兄弟，每年全家人都會上山與族人一同過節。因為熱愛台灣，決定與波蘭籍的太太一同定居台灣，並在中大地科系念了地質博士(指導教授為張中白老師)。Jack專長為地形學、構造地質學、構造地形學、野外地質學。對於台灣南部地質與地形非常熟悉。

Abstract
Newly emerged landscapes above sea level are characterized by rapidly evolving geomorphic systems where the initial fluvial pattern adapts to a former submarine topography. Such an early formed fluvial system establishes drainage basins and unstable landforms that characterize high topographic asymmetry which are prone to fast removal or reorganization. Transitional landscapes might form depositional systems as lakes or ponds that subsequently are incised, captured and incorporated into drainage basins. In this study we focus on the recently emerged Hengchun Peninsula to survey its paleoenvironment evolution. Three drillings performed in the Gangkou basin with fieldwork revealed several indicators that reconstructed stages of the landscape reorganization. The major finding shows an ephemeral large lake in the central part of the Hengchun Peninsula that was drained to the Pacific c. 6000 BP. The lake belonged to an ephemeral lakeland that was created after the emergence of the peninsula. Currently, several areas as relict landforms indicate this stage of topography evolution that through high rates of incision and subsequent captures, transforms into drainage basins. Furthermore, two drillings show brackish waters at the present estuary of the Gangkou basin. These two different paleoenvironments today build one system – Gangkou catchment. Long-term uplift rates show that a hanging wall of the Hengchun Fault plays a significant role in the creation of a lakeland by tilting the peninsula’s surface. The tilt impacts on asymmetrical emergence of the peninsula and catchment development. Our study shows that a new geomorphic system might create depositional ephemeral landforms (lakes) that represent phases of early topography evolution after emergence above a sea level that are subjected to instantaneous rearrangement and evolves through large-scale phases before it
reaches a topographic steady-state.

黏土礦物在沉積物搬運與堆積的應用實例

Nayak, K., Lin, A.T*., Huang, K.-F., Liu, Z., Nathalie, B., Ratzov, G., Pillutla, R.K., Das, P., Hsu, S.-K. 2021.Clay-mineral distribution in recent deep-sea sediments around Taiwan: Implications for sediment dispersal processes. Tectonophysics 814, DOI: 10.1016/j.tecto.2021.228974.

本期刊論文第一作者為中大"沉積暨盆地研究室"印度籍Nayak小姐，由本人與中研院黃國芳博士共同指導，以及多位共同作者協助而完成。

深海沉積物以泥岩為主，泥岩中又以黏土礦物以及非常細粒的石英為主。這些深海的泥(深海泥)的黏土礦物可能是由原本飄浮在海水中的泥沉澱下來，或者經由深海濁流由陸地搬運至深海堆積。在台灣周遭深海區的黏土礦物主要分三大類：伊萊石+綠泥石、膨潤石、高嶺石。剛好，這三大類分別來自不同的地質區：(1) 伊萊石+綠泥石來自台灣島、(2) 膨潤石來自呂宋火山島(由黑潮帶來)、(3)高嶺石來自中國大陸。

所以研究台灣海域的海床黏土礦物，可以推測這些深海沉積物的來源以及沉積物搬運/沉積作用。本研究室TIGP-ESS博士學位學程的Nayak同學，她利用本研究室歷年來收集的海床岩心，加上2018年台法合作的MD214航次的岩心，研究海床下0-50公分的濁流岩以及半遠洋泥的黏土礦物組成，搭配台灣河口沉積物黏土礦物組成的研究，討論台灣周圍深海沉積物的來源以及濁流的作用。
研究結果發現這黑潮(Kuroshio Current)的影響可真是大，台灣的西南外海、南部外海、東部外海，通通有膨潤石的蹤跡。只有在海底峽谷流域，膨潤石才顯著減少，變成以伊萊石+綠泥石為主。在峽谷流域，因為大量台灣來的沉積物，而稀釋了膨潤石的含量。顯示台灣周圍的海底峽谷，深海濁流可以將台灣來的沉積物非常有效率的輸送(外銷)至深海。而這些峽谷以高屏峽谷流域伊萊石+綠泥石的含量最高，暗示高屏峽谷是這幾千年來，濁流最活躍的峽谷。

Share link (full-text download until August 15, 2021):
https://authors.elsevier.com/a/1dIr598wdwBX0
Publisher link:
https://www.sciencedirect.com/science/article/pii/S0040195121002560
Sedimentology and Basin Research Group (SBRG) NCU link:
http://basin.earth.ncu.edu.tw/People/principal.htm

Abstract
Clay-mineralogy study of Taiwanese river-mouth sediments, recent deep-water seafloor sediments around Taiwan, along with sediments collected from the Tainan shelf edge, have been investigated to access the source and transport of detrital fine-grained sediments. We determined the clay mineralogy in both hemipelagites and turbidites in the top 50 cm of the deep-sea sediment cores to infer how sediments are dispersed through river-fed turbidity currents, hypopycnal plumes, and oceanic currents. Our results show that the clay mineral assemblages in both hemipelagites and turbidites of different provinces change gradually between two major end-members: illite+chlorite and smectite. They are predominantly sourced from Taiwan and Luzon, respectively. The relative abundances of clay minerals in turbidites and hemipelagites are quite similar in most of the cores. Therefore, we argue that the adjacent turbidites and hemipelagites of a core share common detrital clay sources. We found that smectite is relatively abundant around Taiwan, indicating that the Kuroshio Current is an important transportation system, which brings smectite from Luzon. Besides, the river-related canyon systems consist dominantly of illite and chlorite, and less smectite, indicating that the smectite brought about by the Kuroshio Current is diluted by river-fed hyperpycnal and hypopycnal flows. This also implies that flood-induced turbidity currents are efficient agents for transporting Taiwan-derived sediments into the neighboring deep-sea basins.

台灣二氧化碳地質封存系列2：
台灣主要二氧化碳排放源與排放量以及地理分布
======

本系列文1提到台灣年碳排約二億六千萬噸。本系列2探討主要二氧化碳排放源是那些公司/工廠？年排放量？地理分布？這些資訊關係到未來碳捕存的可能位置。

根據環保署環境資源資料開放平台(https://opendata.epa.gov.tw/Data/Contents/GreenhouseGas/?fbclid=IwAR1zlxGemAwEZ3pTcU_TYnSGiamCMDvfeL9--ipkk3AL8qTahAYi57ZfzaA)
的2019年二氧化碳排放資料。該年台灣年碳排為259百萬噸(2億5千9百萬噸)，其中能源/工業部門的排放量為218百萬噸左右，佔比為84%。所以能源/工業部門的碳排放比例最高，且為固定排放源。若未來進行碳捕存是最理想的排放源。

統計結果發現2019年台灣年排碳前10名如下列(如圖一)。括號內為2019年排碳量，百分比為此排放量佔能源/工業部門的排放比例：
1. 台電(90.48百萬噸，41.32%)
2. 台塑(40.41百萬噸，18.46%)
3. 中鋼(29.24百萬噸，13.36%)
4. 和平電廠(7.6百萬噸，3.47%)
5. 台灣中油(6.71百萬噸，3.07%)
6. 台化纖(5.15百萬噸，2.35%)
7. 台泥(4.26百萬噸，1.94%)
8. 亞泥(2.93百萬噸，1.34%)
9. 南亞塑(2.63百萬噸，1.2%)
10. 華亞(2.39百萬噸，1.09%)

如果再細究這些公司有哪些主要排放源，我們由環保署網站，可整理出28個排放源。其2019年之年碳排大於1百萬噸，如圖二所示。如果用排放源碳排量來排名，前10名分別是：
1. 麥寮石化廠(27.14百萬噸)
2. 台中發電廠(26.67百萬噸)
3. 中鋼小港廠(20.29百萬噸)
4. 興達發電廠(17.72百萬噸)
5. 林口發電廠(12.07百萬噸)
6. 大林發電廠(11.44百萬噸)
7. 大潭發電廠(10.73百萬噸)
8. 麥寮汽電廠(9.59百萬噸)
9. 中龍鋼鐵龍井廠(8.83百萬噸)
10. 和平發電廠(7.60百萬噸)

圖三顯示主要排碳源的分布、台灣陸上地質、活動斷層與油氣封閉構造。圖中顯示，排源源主要位於台灣西北部、西部、西南部，且鄰近海岸。台灣東北部也有零星分布。

台灣二氧化碳地質封存系列1：
台灣二氧化碳1990-2020年排放量以及2021-2070預測排放量與IEA建議減碳策略

近幾年來，台灣一年排放二氧化碳約二億六千萬噸，佔全世界二氧化碳排放量約0.7-0.8%，排碳量世界排名介於第20-30名之間。平均每人每年排放約11-12公噸之間(全球人均年排碳量約4-5公噸之間)。我國在2010年的「溫室氣體減量法」中，明訂於2050年二氧化碳排放量要回到台灣2005年排放量的一半，就是希望在2050年時年碳排為1億4千萬噸。然而，最近國際減碳動作更加積極。歐盟在2019年底，提出2050淨零碳排（碳中和)，緊接著，也有120個國家跟進、提出2050年達到淨零碳排。據說歐盟也即將開始課徵碳關稅，幾個跨國企業/品牌(如Google, Apple, Microsoft)也做出淨零碳排的承諾。我國政府面對國際大環境，也決定要積極減碳。

4/22是地球日，蔡總統也在臉書宣誓「2050淨零轉型」。她說：「全世界的目標，也是台灣的目標，把握國際趨勢，規劃2050年達到淨零排放的路徑」。圖一顯示台灣過去1990-2020的碳排放量，以及未來2021-2070的年碳排趨勢(圖中最上面的那條黑線)，未來年排碳量則利用國際能源總署（International Energy Agency, IEA, https://www.iea.org/）
所提出的全球年碳排預測趨勢來估計(圖一)。我國「溫室氣體減量法」預期於2050年碳排為1億4千萬噸的目標，也用紅色虛線標示。圖一顯示，若在2050年要達到「溫室氣體減量法」所宣示的排放量，要每年減碳約1億6千萬噸，若要達到蔡總統與國際趨勢所宣示的2050淨零碳排，那要在2050這年，年減碳約2億8千萬噸。用台中火力發電廠2019年排碳量2千6百萬噸來算，等於是把台中電廠關掉，只減少十分之一，可見減碳工程的艱難與遙不可及。但是現在不減碳，碳排永遠居高不下。

那要如何大量減碳呢？國際能源總署(IEA)建議8項方法/技術，來降低碳排，期望在2070年(注意，不是2050年)達到淨零碳排。這8項方法/技術，由高到低減碳比例，分別為：(1) Electrification (電氣化24.5%)、(2) Carbon Capture Utilization and Storage (CCUS二氧化碳捕獲、再利用及封存19.15%)、(3) Other renewables (再生能源19.07%)、(4) Bioenergy (生質能11.87%)、(5) Technology performance (技術性能9.18%)、(6) Hydrogen(氫能7.68%)、(7) Avoided demand (節約能源6.86%)、(8 ) Other fuel shifts (其他能源轉換1.69%)。

上述減碳技術/方法，碳捕存與再利用(CCUS)在全球已有多項大型計畫，進行大規模碳捕存。如果台灣依據IEA建議，有約19%的減碳量，來自碳捕存技術，預估在2070年，CCUS可幫助減碳約5千萬噸。若一口井平均一年灌注1百萬噸，大約要有50口灌注井，以及數十個二氧化碳捕獲廠。這種規模，如果政府/企業有決心減碳，以台灣的地質條件，應該不難達成。

A research paper from our lab:

Lin, A.T., Yang, C.-C., Wang, M.-H., Wu, J.-C. (2021) Oligocene-Miocene sequence stratigraphy in the northern margin of the South China Sea: An example from Taiwan. Journal of Asian Earth Sciences 213, 104765.

Free download from the publisher (until 2021/5/26): https://authors.elsevier.com/a/1csdI4t1lM68DC　

Download pdf file from research group homepage: http://basin.earth.ncu.edu.tw/....../LinAT_etal_2021......
Visit my lab page: http://basin.earth.ncu.edu.tw/People/principal.htm

台灣的漸新世至中新世地層(地層年代大約3000萬年前至650萬年前)，乃是堆積於南中國海北坡的被動大陸邊緣。一般堆積於被動大陸邊緣的地層不容易出露於地表，但因650萬年開始的呂宋島弧與南海北坡碰撞，使得南海北坡的地層出露在寶島台灣。因此，台灣成為研究被動大陸邊緣地層的寶地。

本研究室與台灣中油合作，利用中油在台灣西部麓山帶、平原區與台灣海峽的200多口油氣探勘井與反射震測資料，利用層序地層觀念，以及中油先前建立的各井生物地層，建立台灣漸新世至中新世的地層對比，解析地體構造演育。研究成果將於2021年6月發表於Journal of Asian Earth Sciences期刊，全文下載網址如下(免費下載直到2021/5/26)：https://authors.elsevier.com/a/1csdI4t1lM68DC

台灣的漸新世至中新世地層因為側向岩性改變，即所謂有「同時異相」的現象，於各地區有不同地層名稱。大家最熟悉的地層名稱，由老至新分別為：五指山層、木山層、大寮層、石底層、北寮層、打鹿頁岩、觀音山砂岩、南莊層等。在濁水溪以南、或是台灣海峽南部，因為岩性改變，上述地層名稱，大多已不適用。由於岩性地層南北對比困難，使得漸新世至中新世地層的區域性研究以及沉積體系暨構造演育一直困擾地質學家。

本研究打破岩性地層框架，成功利用層序地層(sequence stratigraphy)觀念，輔以井下生物地層，進行全台灣陸海域的漸新世至中新世地層對比。本研究重要成果如下：

1. 將台灣漸新世地層分為北台灣的O2與O4兩個層序(O代表Oligocene)、南臺灣的TO0與TO2(T代表台南盆地、O表示Oligocene)、中新世地層分成14個層序(M0、M2、M4、M6、M8、M10、M12、M14、M16、M18、M20、M22、M24、M26，其中M代表Miocene)。

2. 前述層序，由老到新，可再組成A、B、C、D四個層序組(sequence set)。

3. A層序組(3000萬年至2100萬年之間)，包含北台灣的O2+O4+M0等三層序(相當於五指山層+木山層)，以及台南盆地的TO0+TO2+TM0等三層序(為中油內部通稱的漸新世海進基底砂岩、漸新世頁岩與早期中新世地層等)。A層序組堆積於張裂盆地，在台灣北部伴隨的火成活動，稱為公館火成活動期。台灣南部的火成岩體，主要出現於台南盆地大陸斜坡之下。本期地層是台灣的重要生油岩與油氣儲集層。

4. B層序組(2100萬年至1730萬年之間)南北對比良好，包含M2+M4+M6+M8+M10+M12+M14等層序，相當於大寮層+石底層+北寮層下部等岩性地層單位。本層序組堆積於緩慢沉陷的被動大陸邊緣，沒有明顯的張裂作用。B層序組分布最廣的地層面為大寮層(或碧靈頁岩)的Mollusca Limestone(於北港高區命名，本文稱為M-L-M面，M-L-M為Miogypsina-Lepidocyclina-Mollusca的縮寫)，為M2層序的最大海漫面(maximum flooding surface)。此M-L-M地層面，大約相當於野柳的女王頭層位。

5. C層序組(1730萬年至1250萬年之間)南北可對比，包含M16+M18+M20等三層序，相當於北寮層(上部)+打鹿頁岩+觀音山砂岩等三地層。C層序組堆積於緩慢沉陷的被動大陸邊緣，沒有明顯的張裂作用。本層序組分布最廣的地層面，分別為M16的最大海漫面(稱為H-O面，H-O為Heterolepa-Orbitoid縮寫)與M20的最大海漫面(稱為Oa-O面，Oa-O為Operculina ammonoides-Operculina縮寫)。其中H-O面於台灣西北部麓山帶以及北港高區為北寮層與打鹿頁岩交界；於台灣海峽北部則位於打鹿頁岩內；此地層面於台南盆地，中油內部報告的震測解釋，稱為green horizon。Oa-O面即為觀音山砂岩內的Operculina有孔蟲富集帶。

6. C層序組在台灣北部之岩性地層為打鹿頁岩與觀音山砂岩，打鹿頁岩在台灣西北部為三角洲沉積，因此發育多層厚層砂岩。在台灣西北部，中油內部報告將打鹿頁岩細分為下部頁岩、打鹿砂岩、上部頁岩等三個地層單位，其中的打鹿砂岩為台灣西北部油氣構造的主要生產層。本研究利用層序地層概念，建立各砂岩層的正確時空關係。

7. D層序組(1250萬年至650萬年之間)，包含M22+M24+M26等三層序，相當於南莊層。本層堆積於張裂盆地中，在北台灣伴隨角板山火成活動。在台南盆地，沉積物堆積於北部凹陷，北界是義竹斷層，南界是中央隆起帶。義竹斷層以北以及中央隆起帶，分別為北部凹陷邊界斷層的下盤，因此成為侵蝕性高區。

8. 本研究成功利用層序地層對比台灣陸海域的漸新世至中新世岩性地層，成為石油探勘、二氧化碳地質封存、地質研究的重要參考資料。

Abstract

Oligocene-Miocene sediments in the Taiwan region were accumulated in the NE passive-continental margin of the South China Sea. We utilized around ~200 boreholes and reflection seismic data to study the Oligo-Miocene sequence stratigraphic framework in the Taiwan region. Major sequence boundaries are used to map out various sediment isopach maps, enabling us to decipher dominant tectonic events during the course of passive-margin evolution.

The Oligocene-Miocene succession is divided into 16 sequences on the basis of well-log correlation. These 16 sequences can be grouped into four (A, B, C, D) sequence sets. Isopach maps of sequence sets B and C (~21–12.5 Ma) show that they blanket the west Taiwan basins with relatively uniform thickness deposited during uniform and slow basement subsidence. Sequence sets A (~30–21 Ma) and D (~12.5–6.5 Ma), however, thickened into fault-bounded troughs, recording two extensional events that were especially active in the outer margin (i.e., the Tainan Basin). There is a general correlation between the Taiwan Miocene sequences and the glacioeustasy during the interval ~21–6.5 Ma. Therefore, eustasy is the dominant control on the Taiwan Miocene stratigraphic development. The deposition of the sequence set A during ~30–21 Ma and possibly the sequence set D in the outer margin during the late Miocene, however, appears to have been strongly modulated by extensional tectonics and local sedimentary factors (e.g., rates of basin subsidence, sediment supply and basin physiography, etc.).