本研究係利用南海北部之岩心及沉積物收集器樣本，分析岩心中Pb-210活度之垂直分佈以估計沉積速率和質量通量以及沉降顆粒之顆粒通量和Pb-210活度之時序變化。主要目的是比較並探討由沉積物收集器所得之顆粒質量通量及Pb-210活度與其通量和由岩心在此區域分析所得結果之質量平衡問題。
位於南海北部的M3S、M1T二測站收集器之時序平均顆粒通量皆隨深度增加，深層收集器受到側向傳輸影響，顆粒質量通量明顯高於上層；上層與中層收集器之間其顆粒質量通量在時序變化則較有同步性的趨勢。位於呂宋海峽附近之S5測站則因地形及底流影響，其平均顆粒通量明顯高於其他兩測站。Pb-210活度的分佈受顆粒清除作用影響，沉降顆粒在沉降過程中滯留時間愈長，其清除周圍水體中Pb-210的機會就愈大。M3S站沉降顆粒之Pb-210活度在時序變化大致上有同步變化趨勢，且隨深度增加。M1T站由於分析樣品較少，不易見其Pb-210活度之時序變化。在邊緣海大都可見Pb-210活度和質量通量在時序變化上呈現負相關，本研究亦如此。
南海北部陸棚外緣岩心I之含水量平均為28%，L.O.I.值為3.2%，和前人於南海北部近岸地區所得之岩心含水量25% ~37%及L.O.I.值3% ~8%的結果相似。本研究區域之沉積速率藉由岩心I中超量Pb-210分佈所估得，其值為18cm/100yr，此值與吳(2006)於南海北部岩心所得之16~52 cm/100yr之下限相當。由Pb-210存量(I)求得之沉積物通量和沉積速率皆和由沉積速率上限所估之值相同，皆為0.32 g/cm2/yr及18 cm/100yr，表示I站之混合作用可忽略。
深層收集器(2163米)(M3S)之Pb-210通量(77.4 dpm/m2/d)遠小於由沉積物(F：吳，2006)所得者(761.1 dpm/m2/d)，雖Pb-210在顆粒上的比活度遠大於表層沉積物活度，但因質量通量遠小於由沉積物所得之通量，顯示岩心中有外來沉積物及Pb-210之側向輸入與堆積，造成沉降顆粒與沉積物兩者間有極大的質量與Pb-210不平衡。

In this study, the sediment cores taken in the northern South China Sea (SCS) as well as the settling particulates collected from time-series sediment traps deployed in the same area have been analyzed for Pb-210 activities in order to estimate the sedimentation rate and mass flux from core data and to obtain temporal variations in mass flux and Pb-210 from the time-series sediment traps. The main purposes are to compare and to discuss the mass balance problem between the sediment trap and core results in terms of mass flux, Pb-210 activity and its fluxes.
The time-averaged particulate fluxes measured from different depths at M3S and M1T sites in the northern SCS generally increase with depth, reflecting an increasing effect of the lateral transport. The upper and middle traps display a synchronous trend in mass flux variations. The mean particulate flux at S5 site near Luzon Strait is clearly higher than the two sites mentioned above probably because of the effect of topography and bottom current. Distributions of Pb-210 are influenced by particulate scavenging: the longer the settling particles stay in the water column the more the surrounding Pb-210 will be scavenged. The temporal variations of Pb-210 at M3S show a similar trend and an increase with depth. At M1T site, the temporal variations of Pb-210 show no clear trend due to insufficient samples. It has been commonly observed in the marginal sea that Pb-210 activity is inversely correlated with the associated mass flux, i.e. higher Pb-210 is associated with lower mass flux in terms of their temporal variations. This study is also in line with such observations.
The mean water content of the core at I located near the shelf break in the northern SCS is about 28%, and its mean loss on ignition (L.O.I.) is 3.2%. These are similar to those observed previously in the northern SCS (water content: 25-37%; L.O.I.: 3%-8%). The sedimentation rate as determined from the excess Pb-210 profile at core I is 18cm/100yr which is at the lower end of the previous study (16-52 cm/100yr) (Wu, 2006). The sediment flux and sedimentation rate estimated from both the Pb-210 inventory (I) and the upper limit of sedimentation rate are identical, respectively, at 0.32 g/cm2/yr and 18cm/100yr. Thus the mixing effect could be neglected. The Pb-210 flux estimated from the deep sediment trap at 2163m (M3S, 77.4 dpm/m2/d) is much lower than that observed from the core sediment (F, 761.1 dpm/m2/d). Although the specific Pb-210 activity of the particles is much greater than that in the surface sediment, the particle flux is too small relative to the mass flux of the sediment, suggesting that additional sediment with Pb-210 has been transported laterally from elsewhere and deposited here. This results in a large imbalance between the sinking particulates and the underlying sediment in mass flux and Pb-210 flux.

頁碼
中文摘要………………………………………………………..………..I
英文摘要………………………………………………………………..III
目錄………………………………………………………………….......V
圖目錄………………………………………………………………...VIII
表目錄…………………………………………………………………...X

一、緒論…………………………………………………………………..1
1.1研究背景………………………………………………………….1
1.2研究目的………………………………………………………….4
二、研究方法及材料……………………………………………………..5
2.1 採樣地點………………………………………………………...5
2.2 核種分析………………………………………………………...9
2.2.1 前處理……………………………………………………9
2.2.2 燒失量(L.O.I.)…………………………………………..11
2.2.3 酸煮樣品………………………………………………..11
2.2.4 Po-210自鍍方法………………………………………12
2.2.5 再生Bi-210測量法(β法) ……………………………..14
2.2.6 以α法偵測Pb-210活度之計算方法…………………..17
2.2.7 以β法偵測Pb-210活度之計算方法…………………..18
2.2.8 不同分析方法偵測Pb-210之比較……………………..20
三、結果與討論…………………………………………………………22
3.1沉降顆粒部分…………………………………………………...22
3.1.1顆粒通量(particulate flux)……………………………….22
3.1.1.1 M3S錨碇站各深度顆粒通量之時序變化………..22
3.1.1.2 M1T錨碇站顆粒通量之時序變化………………..28
3.1.1.3 S5錨碇站各深度顆粒通量之時序變化………….31
3.1.2各測站之Pb-210活度之時序變化……………………...33
3.1.2.1 M3S各深度Pb-210活度之時序變化………….…33
3.1.2.2 M1T 各深度Pb-210活度之時序變化……………34
3.1.2.3 S5錨錠站Pb-210活度之時序變化……………….34
3.1.3顆粒通量與Pb-210活度變化之相關性………………...38
3.1.4各測站之時序平均Pb-210通量………………………...42
3.1.5南海北部各錨錠站時序平均顆粒通量及時序平均Pb-210通量之比較.…………………………………………...…42
3.2 岩心部分……………………………………………………….45
3.2.1 測站I岩心含水率之變化……………………………....45
3.2.2 各測站岩心有機質含量之變化………………………..45
3.2.3 各測站岩心Pb-210之活度分佈………………………..52
3.2.4岩心之沉積速率與測站I之結果……………………….55
3.2.5 Pb-210之存量(inventory)和通量(flux)…………………58
3.3 沉降顆粒與岩心之質量通量及Pb-210通量比較……………..61
四、結論…………………………………………………………………62
伍、參考文獻…………………………………………………..………..64
中文部分…………………………………………………………..64
英文部分…………………………………………………………..66
圖目錄
頁碼
圖1.1、海洋中Po-210與Pb-210來源及傳輸示意圖…………...….……3
圖2.1、研究區域之海底地形及站位圖……………………………….....6
圖2.2、樣品分析流程簡圖……………………………………………...16
圖2.3、Pb-210射源因自我吸收效應而改變效率之校正曲線..20
圖3.1、M3S錨錠站沉降顆粒質量通量之時序變化圖………………..27
圖3.2、M1T錨錠站沉降顆粒質量通量之時序變化圖………………..27
圖3.3、S5(2911m)錨錠站沉降顆粒質量通量之時序變化圖………….32
圖3.4、M3S錨錠站沉降顆粒Pb-210活度之時序變化圖……………36
圖3.5、M1T錨錠站沉降顆粒Pb-210活度之時序變化圖……………36
圖3.6、S5錨錠站淺層(2911米)沉降顆粒Pb-210活度之時序變化圖..37
圖3.7、M3S錨錠站沉降顆粒Pb-210活度與質量通量之相關性圖…..40
圖3.8、M1T錨錠站沉降顆粒Pb-210活度與質量通量之相關性圖…..40
圖3.9、S5(2911米)錨錠站沉降顆粒Pb-210活度與質量通量之相關
性圖……………………...…………………………..………….41
圖3.10、岩心I之含水率分佈剖面圖…………………………………..50
圖3.11、岩心I之L.O.I.分佈剖面圖……………………………………50
圖3.12、岩心17922-2之L.O.I.分佈剖面圖……………………………51
圖3.13、岩心17941-2之L.O.I.分佈剖面圖……………………………51
圖3.14、岩心I之Pb-210活度分佈剖面圖……………………………..53
圖3.15、岩心17922-2之Pb-210活度分佈剖面圖……………………..53
圖3.16、岩心17941-2之Pb-210活度分佈剖面圖……………………..54
圖3.17、岩心I超量Pb-210之自然對數分佈…………………………..57
表目錄
頁碼
表2.1、沉積物時序收集器錨錠站之相關資料………………………….7
表2.2、岩心採樣位置及相關資料……………………………………….8
表2.3、M1站相同岩心樣本以α法分析之Pb-210活度比較……...…13
表2.4、β計數儀偵測效率測定結果…………………………………...19
表2.5、以α法及β法分析I站岩心Pb-210活度之比較………………21
表3.1、各錨錠串列樣品之重量、顆粒通量及210Pb活度………………24
表3.2、M1T錨錠站所有樣本之質量通量……………………………..30
表3.3、南海北部錨錠測站之顆粒時序平均通量與時序平均Pb-210活
度及通量之比較……………………………………………….44
表3.4.1、岩心I之含水率、L.O.I.及210Pb活度分析結果……………...47
表3.4.2、岩心17922-2之L.O.I.及210Pb活度分析結果……..…………48
表3.4.3、岩心17941之L.O.I.及210Pb活度分析結果…………….…....49
表3.5、簡單模式計算所得之沉積速率、超量Pb-210存量及超量Pb-210通量之比較……………………………………………………..60

中文部分
王平，2006，南海北部及呂宋海峽海域浮游生物之釙-210與鉛-210分佈及其活度不平衡，國立中山大學海洋地質研究所碩士論文，共65頁。
朱燐烽，2000，南沖繩海槽西端之鉛-210與釙-210：分佈型態及其活性不平衡現象，國立中山大學海洋地質研究所碩士論文，共53頁。
李粹中，1991，南海深海沉積物14C測年和近代沉積物速率的研究，海洋學報，12(3)，340-346。
吳政臻，2006，南海北部沉降顆粒及沉積物中Pb-210與質量通量之比較，國立中山大學海洋地質研究所碩士論文，共53頁。
邱薰慧，2000，台灣周圍海域浮游生物之釙-210和鉛-210含量及釙-210之富集現象，國立中山大學海洋地質研究所碩士論文，共61頁。
張婉琪，1993，台灣東北海域沉積物鈾釷系列核種之地球化學，國立中山大學海洋地質研究所碩士論文，共43頁。
張慧貞，2002，南海北部海域及高屏峽谷之沈降顆粒及沈積物：通量、粒徑與鉛、釙不平衡，國立中山大學海洋地質及化學研究所碩士論文，共51頁。
陳平，1996，台灣海域及高雄地區大氣懸浮微粒之粒徑分析與鉛-210活度分佈，國立中山大學海洋地質及化學研究所碩士論文，共70頁。
蔡守文，1989，台灣海峽沈積物鉛-210定年法之應用，國立中山大學海洋地質及化學研究所碩士論文，共51頁。
蔡雅婷，1999，鉛-210及鈾釷同位素在沉降顆粒中不同粒徑上之分佈及其意義，國立中山大學海洋地質及化學研究所碩士論文，共62頁。
英文部分
Anderson, R. F. and S. L. Schiff, 1987. Determining sediment accumulation and mixing rates using 210Pb, 137Cs, and other tracers: Problems due to post depositional mobility or coring artifacts. Can. J. Fish. Aquat. Sci., 44, 231-250.
Benninger, L. K. and S. Krishnaswami, 1981. Sedimentary processes in the inner New York Bight：evidence from excess Pb-210 and Pu-239,Pu-240. Earth Planet. Sci. Lett., 53, 158-174.
Chen, C.- T. A. and S. L. Wang, 1998. Influence of Intermediate water in the western Okinawa Trough by the outflow from the South China Sea. J. Geophys. Res., 103, 12,683-12,688.
Chung, Y. and W. C. Chang, 1996. Uranium and Thorium isotopes in marine sediments off northeastern Taiwan. Marine Geology, 133, 89-102.
Chung, Y. and G. W. Hung, 2000. Particulate fluxes and transports on the slope between the southern East China Sea and the South Okinawa Trough. Continental Shelf Research, 20, 571-597.
Chung, Y., K. Chung, H. C. Chang, L. W. Wang, C. M. Yu, and G. W. Hung, 2003. Variabilities of particulate flux and 210Pb in the southern East China Sea and Western South Okinawa Trough. Deep-Sea Research Part II, 50, 1163-1178.
Chung, Y., H. C. Chang, and G. W. Hung, 2004. Particulate flux and 210Pb determined on the sediment trap and core samples from the northern South China Sea. Continental Shelf Research, 24, 673-691.
Flynn, W. W., 1968. The determination of low levels of polonium-210 in
environmental materials. Anal. Chimica Acta., 43, 221-227.
Gong, G. C., K. K. Liu, C. A. Liu, and S.C. Pai, 1992. The chemical hydrography of the South China Sea west of Luzon and a comparison with the west Philippine Sea. Terrestrial, Atmospheric and Oceanic Science (TAO), 3, 587-602.
Heussner S., R. D. Cherry, and M. Heyraud, 1990. 210Po, 210Pb in sediment trap particles on a Mediterranean continental margin. Continental Shelf Research, 10, 989-1004.
Heyraud, M. and R. D. Cherry, 1983. Correlation of Po-210 and Pb-210 enrichments at the sea-surface microlayer with neuston biomass. Continental Shelf Research, 1, 283-293.
Lee, H. J. and S. K. Chough, 1987. Technical Note: bulk density, void ratio and porosity determined from average grain density and water content: an evaluation of errors. Marine Geotechnology, 7, 53-62.
Liang, Y., and B. Lu, 1986. Acoustic environment and physicomechanical properties of the shelf seabed off the Pearl river mouth. Marine Geotechnology, 6, 377-392.
Nozaki, Y., F. Dobashi, Y. Kato, and Y. Yamamoto, 1998. Distribution of Ra isotopes and the 210Pb and 210Po balance in surface seawaters of the mid Northern Hemisphere. Deep-Sea Research I, 45, 1263-1284.
Tsai, S. W. and Y. Chung, 1989. Pb-210 in the sediments of Taiwan Strait. Acta Oceanogr. Taiwan., 22, 1-13.
Turekian, K. K., L. K. Benninger and E. P. Dion, 1983. 7Be and 210Pb total deposition fluxes at New Haven, Connecticut and at Bermuda J. Geophys. Res., 20, 5411-5415.
Warren, L. A. and A. P. Zimmermann, 1994. Suspended particulate grain size dynamics and their implications for trace metal sorption in the Don River. Aquatic Sciences-Research Across Boundaries, 56, 348-362.
Wetzel, A., 1990. Interrelationships between porosity and other geotechnical properties of slowly deposited, fine-grained marine surface sediments. Marine Geology, 92, 105-113.
Wiesner, M. G., L. F. Zheng, H. K. Wong, Y. Wang and W. Chen, 1996. Fluxes of particulate matter in the South China Sea in：Particle Flux in the ocean. SCOPE Report, 57, 293-312, eds. V. Ittekot, P. Schafer, SS. Honjo and P. J. Depetris.
Wyrtki, K., 1961. Physical Oceanography of the Southeast Asian Waters. NAGA Report, 2, Scripps Institution of Oceanography, La Jolla, California, 195pp.
Yang, H. S., Y. Nozaki, H. Sakai, Y. Nagaya and K. Nakamura, 1986.
Natural and man-made radionuclide distributions in Northwest
Pacific deep-sea sediments: rate of sedimentation, bioturbation and
Ra-226 migration. Geochemical Journal, 20, 29-40.